RecyclerView的使用教程1
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http://blog.csdn.net/lmj623565791/article/details/45059587；
本文出自:【张鸿洋的博客】
概述
RecyclerView出现已经有一段时间了，相信大家肯定不陌生了，大家可以通过导入support-v7对其进行使用。
据官方的介绍，该控件用于在有限的窗口中展示大量数据集，其实这样功能的控件我们并不陌生，例如：ListView、GridView。
那么有了ListView、GridView为什么还需要RecyclerView这样的控件呢？整体上看RecyclerView架构，提供了一种插拔式的体验，高度的解耦，异常的灵活，通过设置它提供的不同LayoutManager，ItemDecoration , ItemAnimator实现令人瞠目的效果。
- 你想要控制其显示的方式，请通过布局管理器LayoutManager
- 你想要控制Item间的间隔（可绘制），请通过ItemDecoration
- 你想要控制Item增删的动画，请通过ItemAnimator
- 你想要控制点击、长按事件，请自己写（擦，这点尼玛。）
基本使用
鉴于我们对于ListView的使用特别的熟悉，对比下RecyclerView的使用代码：
<code class="language-java hljs has-numbering">mRecyclerView = findView(R.id.id_recyclerview);<span class="hljs-comment">//设置布局管理器</span>mRecyclerView.setLayoutManager(layout);<span class="hljs-comment">//设置adapter</span>mRecyclerView.setAdapter(adapter)<span class="hljs-comment">//设置Item增加、移除动画</span>mRecyclerView.setItemAnimator(<span class="hljs-keyword">new</span> DefaultItemAnimator());<span class="hljs-comment">//添加分割线</span>mRecyclerView.addItemDecoration(<span class="hljs-keyword">new</span> DividerItemDecoration( getActivity(), DividerItemDecoration.HORIZONTAL_LIST));</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li></ul><div class="save_code tracking-ad" data-mod="popu_249" style="display: none;"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>
ok，相比较于ListView的代码，ListView可能只需要去设置一个adapter就能正常使用了。而RecyclerView基本需要上面一系列的步骤，那么为什么会添加这么多的步骤呢？
那么就必须解释下RecyclerView的这个名字了，从它类名上看，RecyclerView代表的意义是，我只管Recycler View，也就是说RecyclerView只管回收与复用View，其他的你可以自己去设置。可以看出其高度的解耦，给予你充分的定制自由（所以你才可以轻松的通过这个控件实现ListView,GirdView，瀑布流等效果）。
Just like ListView
- Activity
<code class="language-java hljs has-numbering"><span class="hljs-keyword">package</span> com.zhy.sample.demo_recyclerview;<span class="hljs-keyword">import</span> java.util.ArrayList;<span class="hljs-keyword">import</span> java.util.List;<span class="hljs-keyword">import</span> android.os.Bundle;<span class="hljs-keyword">import</span> android.support.v7.app.ActionBarActivity;<span class="hljs-keyword">import</span> android.support.v7.widget.LinearLayoutManager;<span class="hljs-keyword">import</span> android.support.v7.widget.RecyclerView;<span class="hljs-keyword">import</span> android.support.v7.widget.RecyclerView.ViewHolder;<span class="hljs-keyword">import</span> android.view.LayoutInflater;<span class="hljs-keyword">import</span> android.view.View;<span class="hljs-keyword">import</span> android.view.ViewGroup;<span class="hljs-keyword">import</span> android.widget.TextView;<span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">HomeActivity</span> <span class="hljs-keyword">extends</span> <span class="hljs-title">ActionBarActivity</span>{</span> <span class="hljs-keyword">private</span> RecyclerView mRecyclerView; <span class="hljs-keyword">private</span> List<String> mDatas; <span class="hljs-keyword">private</span> HomeAdapter mAdapter; <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">protected</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onCreate</span>(Bundle savedInstanceState) { <span class="hljs-keyword">super</span>.onCreate(savedInstanceState); setContentView(R.layout.activity_single_recyclerview); initData(); mRecyclerView = (RecyclerView) findViewById(R.id.id_recyclerview); mRecyclerView.setLayoutManager(<span class="hljs-keyword">new</span> LinearLayoutManager(<span class="hljs-keyword">this</span>)); mRecyclerView.setAdapter(mAdapter = <span class="hljs-keyword">new</span> HomeAdapter()); } <span class="hljs-keyword">protected</span> <span class="hljs-keyword">void</span> <span class="hljs-title">initData</span>() { mDatas = <span class="hljs-keyword">new</span> ArrayList<String>(); <span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> i = <span class="hljs-string">'A'</span>; i < <span class="hljs-string">'z'</span>; i++) { mDatas.add(<span class="hljs-string">""</span> + (<span class="hljs-keyword">char</span>) i); } } class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.MyViewHolder> { <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> MyViewHolder <span class="hljs-title">onCreateViewHolder</span>(ViewGroup parent, <span class="hljs-keyword">int</span> viewType) { MyViewHolder holder = <span class="hljs-keyword">new</span> MyViewHolder(LayoutInflater.from( HomeActivity.<span class="hljs-keyword">this</span>).inflate(R.layout.item_home, parent, <span class="hljs-keyword">false</span>)); <span class="hljs-keyword">return</span> holder; } <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onBindViewHolder</span>(MyViewHolder holder, <span class="hljs-keyword">int</span> position) { holder.tv.setText(mDatas.get(position)); } <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">int</span> <span class="hljs-title">getItemCount</span>() { <span class="hljs-keyword">return</span> mDatas.size(); } class MyViewHolder extends ViewHolder { TextView tv; <span class="hljs-keyword">public</span> <span class="hljs-title">MyViewHolder</span>(View view) { <span class="hljs-keyword">super</span>(view); tv = (TextView) view.findViewById(R.id.id_num); } } }}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li><li>32</li><li>33</li><li>34</li><li>35</li><li>36</li><li>37</li><li>38</li><li>39</li><li>40</li><li>41</li><li>42</li><li>43</li><li>44</li><li>45</li><li>46</li><li>47</li><li>48</li><li>49</li><li>50</li><li>51</li><li>52</li><li>53</li><li>54</li><li>55</li><li>56</li><li>57</li><li>58</li><li>59</li><li>60</li><li>61</li><li>62</li><li>63</li><li>64</li><li>65</li><li>66</li><li>67</li><li>68</li><li>69</li><li>70</li><li>71</li><li>72</li><li>73</li><li>74</li><li>75</li><li>76</li><li>77</li><li>78</li><li>79</li><li>80</li><li>81</li><li>82</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>- Activity的布局文件
<code class="language-xml hljs has-numbering"><span class="hljs-tag"><<span class="hljs-title">RelativeLayout</span> <span class="hljs-attribute">xmlns:android</span>=<span class="hljs-value">"http://schemas.android.com/apk/res/android"</span> <span class="hljs-attribute">xmlns:tools</span>=<span class="hljs-value">"http://schemas.android.com/tools"</span> <span class="hljs-attribute">android:layout_width</span>=<span class="hljs-value">"match_parent"</span> <span class="hljs-attribute">android:layout_height</span>=<span class="hljs-value">"match_parent"</span> ></span> <span class="hljs-tag"><<span class="hljs-title">android.support.v7.widget.RecyclerView</span> <span class="hljs-attribute">android:id</span>=<span class="hljs-value">"@+id/id_recyclerview"</span> <span class="hljs-attribute">android:divider</span>=<span class="hljs-value">"#ffff0000"</span> <span class="hljs-attribute">android:dividerHeight</span>=<span class="hljs-value">"10dp"</span> <span class="hljs-attribute">android:layout_width</span>=<span class="hljs-value">"match_parent"</span> <span class="hljs-attribute">android:layout_height</span>=<span class="hljs-value">"match_parent"</span> /></span><span class="hljs-tag"></<span class="hljs-title">RelativeLayout</span>></span></code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>
- Item的布局文件
<code class="language-xml hljs has-numbering"><span class="hljs-pi"><?xml version="1.0" encoding="utf-8"?></span><span class="hljs-tag"><<span class="hljs-title">FrameLayout</span> <span class="hljs-attribute">xmlns:android</span>=<span class="hljs-value">"http://schemas.android.com/apk/res/android"</span> <span class="hljs-attribute">android:layout_width</span>=<span class="hljs-value">"match_parent"</span> <span class="hljs-attribute">android:background</span>=<span class="hljs-value">"#44ff0000"</span> <span class="hljs-attribute">android:layout_height</span>=<span class="hljs-value">"wrap_content"</span> ></span> <span class="hljs-tag"><<span class="hljs-title">TextView</span> <span class="hljs-attribute">android:id</span>=<span class="hljs-value">"@+id/id_num"</span> <span class="hljs-attribute">android:layout_width</span>=<span class="hljs-value">"match_parent"</span> <span class="hljs-attribute">android:layout_height</span>=<span class="hljs-value">"50dp"</span> <span class="hljs-attribute">android:gravity</span>=<span class="hljs-value">"center"</span> <span class="hljs-attribute">android:text</span>=<span class="hljs-value">"1"</span> /></span><span class="hljs-tag"></<span class="hljs-title">FrameLayout</span>></span></code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>
这么看起来用法与ListView的代码基本一致哈~~
看下效果图：
看起来好丑，Item间应该有个分割线，当你去找时，你会发现RecyclerView并没有支持divider这样的属性。那么怎么办，你可以给Item的布局去设置margin，当然了这种方式不够优雅，我们文章开始说了，我们可以自由的去定制它，当然我们的分割线也是可以定制的。
ItemDecoration
我们可以通过该方法添加分割线： mRecyclerView.addItemDecoration()
该方法的参数为RecyclerView.ItemDecoration，该类为抽象类，官方目前并没有提供默认的实现类（我觉得最好能提供几个）。
该类的源码：
<code class="language-java hljs has-numbering"><span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">abstract</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">ItemDecoration</span> {</span><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onDraw</span>(Canvas c, RecyclerView parent, State state) { onDraw(c, parent); }<span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onDrawOver</span>(Canvas c, RecyclerView parent, State state) { onDrawOver(c, parent); }<span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">getItemOffsets</span>(Rect outRect, View view, RecyclerView parent, State state) { getItemOffsets(outRect, ((LayoutParams) view.getLayoutParams()).getViewLayoutPosition(), parent);}<span class="hljs-annotation">@Deprecated</span><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">getItemOffsets</span>(Rect outRect, <span class="hljs-keyword">int</span> itemPosition, RecyclerView parent) { outRect.set(<span class="hljs-number">0</span>, <span class="hljs-number">0</span>, <span class="hljs-number">0</span>, <span class="hljs-number">0</span>); }</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>当我们调用mRecyclerView.addItemDecoration()方法添加decoration的时候，RecyclerView在绘制的时候，去会绘制decorator，即调用该类的onDraw和onDrawOver方法，
- onDraw方法先于drawChildren
- onDrawOver在drawChildren之后，一般我们选择复写其中一个即可。
- getItemOffsets 可以通过outRect.set()为每个Item设置一定的偏移量，主要用于绘制Decorator。
接下来我们看一个RecyclerView.ItemDecoration的实现类，该类很好的实现了RecyclerView添加分割线（当使用LayoutManager为LinearLayoutManager时）。
该类参考自：DividerItemDecoration
<code class="language-java hljs has-numbering"><span class="hljs-keyword">package</span> com.zhy.sample.demo_recyclerview;<span class="hljs-comment">/* * Copyright (C) 2014 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * limitations under the License. */</span><span class="hljs-keyword">import</span> android.content.Context;<span class="hljs-keyword">import</span> android.content.res.TypedArray;<span class="hljs-keyword">import</span> android.graphics.Canvas;<span class="hljs-keyword">import</span> android.graphics.Rect;<span class="hljs-keyword">import</span> android.graphics.drawable.Drawable;<span class="hljs-keyword">import</span> android.support.v7.widget.LinearLayoutManager;<span class="hljs-keyword">import</span> android.support.v7.widget.RecyclerView;<span class="hljs-keyword">import</span> android.support.v7.widget.RecyclerView.State;<span class="hljs-keyword">import</span> android.util.Log;<span class="hljs-keyword">import</span> android.view.View;<span class="hljs-javadoc">/** * This class is from the v7 samples of the Android SDK. It's not by me! * <p/> * See the license above for details. */</span><span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">DividerItemDecoration</span> <span class="hljs-keyword">extends</span> <span class="hljs-title">RecyclerView</span>.<span class="hljs-title">ItemDecoration</span> {</span> <span class="hljs-keyword">private</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span>[] ATTRS = <span class="hljs-keyword">new</span> <span class="hljs-keyword">int</span>[]{ android.R.attr.listDivider }; <span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL; <span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> VERTICAL_LIST = LinearLayoutManager.VERTICAL; <span class="hljs-keyword">private</span> Drawable mDivider; <span class="hljs-keyword">private</span> <span class="hljs-keyword">int</span> mOrientation; <span class="hljs-keyword">public</span> <span class="hljs-title">DividerItemDecoration</span>(Context context, <span class="hljs-keyword">int</span> orientation) { <span class="hljs-keyword">final</span> TypedArray a = context.obtainStyledAttributes(ATTRS); mDivider = a.getDrawable(<span class="hljs-number">0</span>); a.recycle(); setOrientation(orientation); } <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setOrientation</span>(<span class="hljs-keyword">int</span> orientation) { <span class="hljs-keyword">if</span> (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) { <span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> IllegalArgumentException(<span class="hljs-string">"invalid orientation"</span>); } mOrientation = orientation; } <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onDraw</span>(Canvas c, RecyclerView parent) { Log.v(<span class="hljs-string">"recyclerview - itemdecoration"</span>, <span class="hljs-string">"onDraw()"</span>); <span class="hljs-keyword">if</span> (mOrientation == VERTICAL_LIST) { drawVertical(c, parent); } <span class="hljs-keyword">else</span> { drawHorizontal(c, parent); } } <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">drawVertical</span>(Canvas c, RecyclerView parent) { <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> left = parent.getPaddingLeft(); <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> right = parent.getWidth() - parent.getPaddingRight(); <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> childCount = parent.getChildCount(); <span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> i = <span class="hljs-number">0</span>; i < childCount; i++) { <span class="hljs-keyword">final</span> View child = parent.getChildAt(i); android.support.v7.widget.RecyclerView v = <span class="hljs-keyword">new</span> android.support.v7.widget.RecyclerView(parent.getContext()); <span class="hljs-keyword">final</span> RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child .getLayoutParams(); <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> top = child.getBottom() + params.bottomMargin; <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> bottom = top + mDivider.getIntrinsicHeight(); mDivider.setBounds(left, top, right, bottom); mDivider.draw(c); } } <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">drawHorizontal</span>(Canvas c, RecyclerView parent) { <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> top = parent.getPaddingTop(); <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> bottom = parent.getHeight() - parent.getPaddingBottom(); <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> childCount = parent.getChildCount(); <span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> i = <span class="hljs-number">0</span>; i < childCount; i++) { <span class="hljs-keyword">final</span> View child = parent.getChildAt(i); <span class="hljs-keyword">final</span> RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child .getLayoutParams(); <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> left = child.getRight() + params.rightMargin; <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> right = left + mDivider.getIntrinsicHeight(); mDivider.setBounds(left, top, right, bottom); mDivider.draw(c); } } <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">getItemOffsets</span>(Rect outRect, <span class="hljs-keyword">int</span> itemPosition, RecyclerView parent) { <span class="hljs-keyword">if</span> (mOrientation == VERTICAL_LIST) { outRect.set(<span class="hljs-number">0</span>, <span class="hljs-number">0</span>, <span class="hljs-number">0</span>, mDivider.getIntrinsicHeight()); } <span class="hljs-keyword">else</span> { outRect.set(<span class="hljs-number">0</span>, <span class="hljs-number">0</span>, mDivider.getIntrinsicWidth(), <span class="hljs-number">0</span>); } }}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li><li>32</li><li>33</li><li>34</li><li>35</li><li>36</li><li>37</li><li>38</li><li>39</li><li>40</li><li>41</li><li>42</li><li>43</li><li>44</li><li>45</li><li>46</li><li>47</li><li>48</li><li>49</li><li>50</li><li>51</li><li>52</li><li>53</li><li>54</li><li>55</li><li>56</li><li>57</li><li>58</li><li>59</li><li>60</li><li>61</li><li>62</li><li>63</li><li>64</li><li>65</li><li>66</li><li>67</li><li>68</li><li>69</li><li>70</li><li>71</li><li>72</li><li>73</li><li>74</li><li>75</li><li>76</li><li>77</li><li>78</li><li>79</li><li>80</li><li>81</li><li>82</li><li>83</li><li>84</li><li>85</li><li>86</li><li>87</li><li>88</li><li>89</li><li>90</li><li>91</li><li>92</li><li>93</li><li>94</li><li>95</li><li>96</li><li>97</li><li>98</li><li>99</li><li>100</li><li>101</li><li>102</li><li>103</li><li>104</li><li>105</li><li>106</li><li>107</li><li>108</li><li>109</li><li>110</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>该实现类可以看到通过读取系统主题中的 android.R.attr.listDivider作为Item间的分割线，并且支持横向和纵向。如果你不清楚它是怎么做到的读取系统的属性用于自身，请参考我的另一篇博文：Android 深入理解Android中的自定义属性
获取到listDivider以后，该属性的值是个Drawable，在getItemOffsets中，outRect去设置了绘制的范围。onDraw中实现了真正的绘制。
我们在原来的代码中添加一句：
<code class="language-java hljs has-numbering">mRecyclerView.addItemDecoration(<span class="hljs-keyword">new</span> DividerItemDecoration(<span class="hljs-keyword">this</span>,DividerItemDecoration.VERTICAL_LIST));</code><ul class="pre-numbering"><li>1</li><li>2</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>
ok，现在再运行，就可以看到分割线的效果了。
该分割线是系统默认的，你可以在theme.xml中找到该属性的使用情况。那么，使用系统的listDivider有什么好处呢？就是方便我们去随意的改变，该属性我们可以直接声明在：
<code class="language-xml hljs has-numbering"> <span class="hljs-comment"><!-- Application theme. --></span> <span class="hljs-tag"><<span class="hljs-title">style</span> <span class="hljs-attribute">name</span>=<span class="hljs-value">"AppTheme"</span> <span class="hljs-attribute">parent</span>=<span class="hljs-value">"AppBaseTheme"</span>></span><span class="css"> <<span class="hljs-tag">item</span> <span class="hljs-tag">name</span>="<span class="hljs-tag">android</span><span class="hljs-pseudo">:listDivider"</span>><span class="hljs-at_rule">@<span class="hljs-keyword">drawable/divider_bg</item></span> </span></span><span class="hljs-tag"></<span class="hljs-title">style</span>></span></code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>
然后自己写个drawable即可，下面我们换一种分隔符：
<code class="language-java hljs has-numbering"><?xml version=<span class="hljs-string">"1.0"</span> encoding=<span class="hljs-string">"utf-8"</span>?><shape xmlns:android=<span class="hljs-string">"http://schemas.android.com/apk/res/android"</span> android:shape=<span class="hljs-string">"rectangle"</span> > <gradient android:centerColor=<span class="hljs-string">"#ff00ff00"</span> android:endColor=<span class="hljs-string">"#ff0000ff"</span> android:startColor=<span class="hljs-string">"#ffff0000"</span> android:type=<span class="hljs-string">"linear"</span> /> <size android:height=<span class="hljs-string">"4dp"</span>/></shape></code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>
现在的样子是：
当然了，你可以根据自己的需求，去随意的绘制，反正是画出来的，随便玩~~
ok，看到这，你可能觉得，这玩意真尼玛麻烦，完全不能比拟的心爱的ListView。那么继续看。
LayoutManager
好了，上面实现了类似ListView样子的Demo，通过使用其默认的LinearLayoutManager。
RecyclerView.LayoutManager吧，这是一个抽象类，好在系统提供了3个实现类：
- LinearLayoutManager 现行管理器，支持横向、纵向。
- GridLayoutManager 网格布局管理器
- StaggeredGridLayoutManager 瀑布就式布局管理器
上面我们已经初步体验了下LinearLayoutManager，接下来看GridLayoutManager。
- GridLayoutManager
我们尝试去实现类似GridView，秒秒钟的事情：
<code class="language-java hljs has-numbering"><span class="hljs-comment">//mRecyclerView.setLayoutManager(new LinearLayoutManager(this));</span> mRecyclerView.setLayoutManager(<span class="hljs-keyword">new</span> GridLayoutManager(<span class="hljs-keyword">this</span>,<span class="hljs-number">4</span>));</code><ul class="pre-numbering"><li>1</li><li>2</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>
只需要修改LayoutManager即可，还是很nice的。
当然了，改为GridLayoutManager以后，对于分割线，前面的DividerItemDecoration就不适用了，主要是因为它在绘制的时候，比如水平线，针对每个child的取值为：
<code class="language-java hljs has-numbering"><span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> left = parent.getPaddingLeft();<span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> right = parent.getWidth() - parent.getPaddingRight();</code><ul class="pre-numbering"><li>1</li><li>2</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>
因为每个Item一行，这样是没问题的。而GridLayoutManager时，一行有多个childItem，这样就多次绘制了，并且GridLayoutManager时，Item如果为最后一列（则右边无间隔线）或者为最后一行（底部无分割线）。
针对上述，我们编写了DividerGridItemDecoration。
<code class="language-java hljs has-numbering"><span class="hljs-keyword">package</span> com.zhy.sample.demo_recyclerview;<span class="hljs-keyword">import</span> android.content.Context;<span class="hljs-keyword">import</span> android.content.res.TypedArray;<span class="hljs-keyword">import</span> android.graphics.Canvas;<span class="hljs-keyword">import</span> android.graphics.Rect;<span class="hljs-keyword">import</span> android.graphics.drawable.Drawable;<span class="hljs-keyword">import</span> android.support.v7.widget.GridLayoutManager;<span class="hljs-keyword">import</span> android.support.v7.widget.RecyclerView;<span class="hljs-keyword">import</span> android.support.v7.widget.RecyclerView.LayoutManager;<span class="hljs-keyword">import</span> android.support.v7.widget.RecyclerView.State;<span class="hljs-keyword">import</span> android.support.v7.widget.StaggeredGridLayoutManager;<span class="hljs-keyword">import</span> android.view.View;<span class="hljs-javadoc">/** * *<span class="hljs-javadoctag"> @author</span> zhy * */</span><span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">DividerGridItemDecoration</span> <span class="hljs-keyword">extends</span> <span class="hljs-title">RecyclerView</span>.<span class="hljs-title">ItemDecoration</span>{</span> <span class="hljs-keyword">private</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span>[] ATTRS = <span class="hljs-keyword">new</span> <span class="hljs-keyword">int</span>[] { android.R.attr.listDivider }; <span class="hljs-keyword">private</span> Drawable mDivider; <span class="hljs-keyword">public</span> <span class="hljs-title">DividerGridItemDecoration</span>(Context context) { <span class="hljs-keyword">final</span> TypedArray a = context.obtainStyledAttributes(ATTRS); mDivider = a.getDrawable(<span class="hljs-number">0</span>); a.recycle(); } <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onDraw</span>(Canvas c, RecyclerView parent, State state) { drawHorizontal(c, parent); drawVertical(c, parent); } <span class="hljs-keyword">private</span> <span class="hljs-keyword">int</span> <span class="hljs-title">getSpanCount</span>(RecyclerView parent) { <span class="hljs-comment">// 列数</span> <span class="hljs-keyword">int</span> spanCount = -<span class="hljs-number">1</span>; LayoutManager layoutManager = parent.getLayoutManager(); <span class="hljs-keyword">if</span> (layoutManager <span class="hljs-keyword">instanceof</span> GridLayoutManager) { spanCount = ((GridLayoutManager) layoutManager).getSpanCount(); } <span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (layoutManager <span class="hljs-keyword">instanceof</span> StaggeredGridLayoutManager) { spanCount = ((StaggeredGridLayoutManager) layoutManager) .getSpanCount(); } <span class="hljs-keyword">return</span> spanCount; } <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">drawHorizontal</span>(Canvas c, RecyclerView parent) { <span class="hljs-keyword">int</span> childCount = parent.getChildCount(); <span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> i = <span class="hljs-number">0</span>; i < childCount; i++) { <span class="hljs-keyword">final</span> View child = parent.getChildAt(i); <span class="hljs-keyword">final</span> RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child .getLayoutParams(); <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> left = child.getLeft() - params.leftMargin; <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> right = child.getRight() + params.rightMargin + mDivider.getIntrinsicWidth(); <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> top = child.getBottom() + params.bottomMargin; <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> bottom = top + mDivider.getIntrinsicHeight(); mDivider.setBounds(left, top, right, bottom); mDivider.draw(c); } } <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">drawVertical</span>(Canvas c, RecyclerView parent) { <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> childCount = parent.getChildCount(); <span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> i = <span class="hljs-number">0</span>; i < childCount; i++) { <span class="hljs-keyword">final</span> View child = parent.getChildAt(i); <span class="hljs-keyword">final</span> RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child .getLayoutParams(); <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> top = child.getTop() - params.topMargin; <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> bottom = child.getBottom() + params.bottomMargin; <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> left = child.getRight() + params.rightMargin; <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> right = left + mDivider.getIntrinsicWidth(); mDivider.setBounds(left, top, right, bottom); mDivider.draw(c); } } <span class="hljs-keyword">private</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">isLastColum</span>(RecyclerView parent, <span class="hljs-keyword">int</span> pos, <span class="hljs-keyword">int</span> spanCount, <span class="hljs-keyword">int</span> childCount) { LayoutManager layoutManager = parent.getLayoutManager(); <span class="hljs-keyword">if</span> (layoutManager <span class="hljs-keyword">instanceof</span> GridLayoutManager) { <span class="hljs-keyword">if</span> ((pos + <span class="hljs-number">1</span>) % spanCount == <span class="hljs-number">0</span>)<span class="hljs-comment">// 如果是最后一列，则不需要绘制右边</span> { <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>; } } <span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (layoutManager <span class="hljs-keyword">instanceof</span> StaggeredGridLayoutManager) { <span class="hljs-keyword">int</span> orientation = ((StaggeredGridLayoutManager) layoutManager) .getOrientation(); <span class="hljs-keyword">if</span> (orientation == StaggeredGridLayoutManager.VERTICAL) { <span class="hljs-keyword">if</span> ((pos + <span class="hljs-number">1</span>) % spanCount == <span class="hljs-number">0</span>)<span class="hljs-comment">// 如果是最后一列，则不需要绘制右边</span> { <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>; } } <span class="hljs-keyword">else</span> { childCount = childCount - childCount % spanCount; <span class="hljs-keyword">if</span> (pos >= childCount)<span class="hljs-comment">// 如果是最后一列，则不需要绘制右边</span> <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>; } } <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>; } <span class="hljs-keyword">private</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">isLastRaw</span>(RecyclerView parent, <span class="hljs-keyword">int</span> pos, <span class="hljs-keyword">int</span> spanCount, <span class="hljs-keyword">int</span> childCount) { LayoutManager layoutManager = parent.getLayoutManager(); <span class="hljs-keyword">if</span> (layoutManager <span class="hljs-keyword">instanceof</span> GridLayoutManager) { childCount = childCount - childCount % spanCount; <span class="hljs-keyword">if</span> (pos >= childCount)<span class="hljs-comment">// 如果是最后一行，则不需要绘制底部</span> <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>; } <span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (layoutManager <span class="hljs-keyword">instanceof</span> StaggeredGridLayoutManager) { <span class="hljs-keyword">int</span> orientation = ((StaggeredGridLayoutManager) layoutManager) .getOrientation(); <span class="hljs-comment">// StaggeredGridLayoutManager 且纵向滚动</span> <span class="hljs-keyword">if</span> (orientation == StaggeredGridLayoutManager.VERTICAL) { childCount = childCount - childCount % spanCount; <span class="hljs-comment">// 如果是最后一行，则不需要绘制底部</span> <span class="hljs-keyword">if</span> (pos >= childCount) <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>; } <span class="hljs-keyword">else</span> <span class="hljs-comment">// StaggeredGridLayoutManager 且横向滚动</span> { <span class="hljs-comment">// 如果是最后一行，则不需要绘制底部</span> <span class="hljs-keyword">if</span> ((pos + <span class="hljs-number">1</span>) % spanCount == <span class="hljs-number">0</span>) { <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>; } } } <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>; } <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">getItemOffsets</span>(Rect outRect, <span class="hljs-keyword">int</span> itemPosition, RecyclerView parent) { <span class="hljs-keyword">int</span> spanCount = getSpanCount(parent); <span class="hljs-keyword">int</span> childCount = parent.getAdapter().getItemCount(); <span class="hljs-keyword">if</span> (isLastRaw(parent, itemPosition, spanCount, childCount))<span class="hljs-comment">// 如果是最后一行，则不需要绘制底部</span> { outRect.set(<span class="hljs-number">0</span>, <span class="hljs-number">0</span>, mDivider.getIntrinsicWidth(), <span class="hljs-number">0</span>); } <span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (isLastColum(parent, itemPosition, spanCount, childCount))<span class="hljs-comment">// 如果是最后一列，则不需要绘制右边</span> { outRect.set(<span class="hljs-number">0</span>, <span class="hljs-number">0</span>, <span class="hljs-number">0</span>, mDivider.getIntrinsicHeight()); } <span class="hljs-keyword">else</span> { outRect.set(<span class="hljs-number">0</span>, <span class="hljs-number">0</span>, mDivider.getIntrinsicWidth(), mDivider.getIntrinsicHeight()); } }}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li><li>32</li><li>33</li><li>34</li><li>35</li><li>36</li><li>37</li><li>38</li><li>39</li><li>40</li><li>41</li><li>42</li><li>43</li><li>44</li><li>45</li><li>46</li><li>47</li><li>48</li><li>49</li><li>50</li><li>51</li><li>52</li><li>53</li><li>54</li><li>55</li><li>56</li><li>57</li><li>58</li><li>59</li><li>60</li><li>61</li><li>62</li><li>63</li><li>64</li><li>65</li><li>66</li><li>67</li><li>68</li><li>69</li><li>70</li><li>71</li><li>72</li><li>73</li><li>74</li><li>75</li><li>76</li><li>77</li><li>78</li><li>79</li><li>80</li><li>81</li><li>82</li><li>83</li><li>84</li><li>85</li><li>86</li><li>87</li><li>88</li><li>89</li><li>90</li><li>91</li><li>92</li><li>93</li><li>94</li><li>95</li><li>96</li><li>97</li><li>98</li><li>99</li><li>100</li><li>101</li><li>102</li><li>103</li><li>104</li><li>105</li><li>106</li><li>107</li><li>108</li><li>109</li><li>110</li><li>111</li><li>112</li><li>113</li><li>114</li><li>115</li><li>116</li><li>117</li><li>118</li><li>119</li><li>120</li><li>121</li><li>122</li><li>123</li><li>124</li><li>125</li><li>126</li><li>127</li><li>128</li><li>129</li><li>130</li><li>131</li><li>132</li><li>133</li><li>134</li><li>135</li><li>136</li><li>137</li><li>138</li><li>139</li><li>140</li><li>141</li><li>142</li><li>143</li><li>144</li><li>145</li><li>146</li><li>147</li><li>148</li><li>149</li><li>150</li><li>151</li><li>152</li><li>153</li><li>154</li><li>155</li><li>156</li><li>157</li><li>158</li><li>159</li><li>160</li><li>161</li><li>162</li><li>163</li><li>164</li><li>165</li><li>166</li><li>167</li><li>168</li><li>169</li><li>170</li><li>171</li><li>172</li><li>173</li><li>174</li><li>175</li><li>176</li><li>177</li><li>178</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>主要在getItemOffsets方法中，去判断如果是最后一行，则不需要绘制底部；如果是最后一列，则不需要绘制右边，整个判断也考虑到了StaggeredGridLayoutManager的横向和纵向，所以稍稍有些复杂。最重要还是去理解，如何绘制什么的不重要。一般如果仅仅是希望有空隙，还是去设置item的margin方便。
最后的效果是：
ok，看到这，你可能还觉得RecyclerView不够强大？
但是如果我们有这么个需求，纵屏的时候显示为ListView，横屏的时候显示两列的GridView，我们RecyclerView可以轻松搞定，而如果使用ListView去实现还是需要点功夫的~~~
当然了，这只是皮毛，下面让你心服口服。
- StaggeredGridLayoutManager
瀑布流式的布局，其实他可以实现GridLayoutManager一样的功能，仅仅按照下列代码：
<code class="language-java hljs has-numbering"><span class="hljs-comment">// mRecyclerView.setLayoutManager(new GridLayoutManager(this,4));</span> mRecyclerView.setLayoutManager(<span class="hljs-keyword">new</span> StaggeredGridLayoutManager(<span class="hljs-number">4</span>, StaggeredGridLayoutManager.VERTICAL));</code><ul class="pre-numbering"><li>1</li><li>2</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>
这两种写法显示的效果是一致的，但是注意StaggeredGridLayoutManager构造的第二个参数传一个orientation，如果传入的是StaggeredGridLayoutManager.VERTICAL代表有多少列；那么传入的如果是StaggeredGridLayoutManager.HORIZONTAL就代表有多少行，比如本例如果改为：
<code class="language-java hljs has-numbering">mRecyclerView.setLayoutManager(<span class="hljs-keyword">new</span> StaggeredGridLayoutManager(<span class="hljs-number">4</span>, StaggeredGridLayoutManager.HORIZONTAL));</code><ul class="pre-numbering"><li>1</li><li>2</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>
那么效果为：
可以看到，固定为4行，变成了左右滑动。有一点需要注意，如果是横向的时候，item的宽度需要注意去设置，毕竟横向的宽度没有约束了，应为控件可以横向滚动了。
如果你需要一样横向滚动的GridView，那么恭喜你。
ok，接下来准备看大招，如果让你去实现个瀑布流，最起码不是那么随意就可以实现的吧？但是，如果使用RecyclerView，分分钟的事。
那么如何实现？其实你什么都不用做，只要使用StaggeredGridLayoutManager我们就已经实现了，只是上面的item布局我们使用了固定的高度，下面我们仅仅在适配器的onBindViewHolder方法中为我们的item设置个随机的高度（代码就不贴了，最后会给出源码下载地址），看看效果图：
是不是棒棒哒，通过RecyclerView去实现ListView、GridView、瀑布流的效果基本上没有什么区别，而且可以仅仅通过设置不同的LayoutManager即可实现。
还有更nice的地方，就在于item增加、删除的动画也是可配置的。接下来看一下ItemAnimator。
ItemAnimator
ItemAnimator也是一个抽象类，好在系统为我们提供了一种默认的实现类，期待系统多
添加些默认的实现。
借助默认的实现，当Item添加和移除的时候，添加动画效果很简单:
<code class="language-java hljs has-numbering"><span class="hljs-comment">// 设置item动画</span>mRecyclerView.setItemAnimator(<span class="hljs-keyword">new</span> DefaultItemAnimator());</code><ul class="pre-numbering"><li>1</li><li>2</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>
系统为我们提供了一个默认的实现，我们为我们的瀑布流添加以上一行代码，效果为：
如果是GridLayoutManager呢？动画效果为：
注意，这里更新数据集不是用adapter.notifyDataSetChanged()而是 notifyItemInserted(position)与notifyItemRemoved(position)
否则没有动画效果。
上述为adapter中添加了两个方法：
<code class="language-java hljs has-numbering"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">addData</span>(<span class="hljs-keyword">int</span> position) { mDatas.add(position, <span class="hljs-string">"Insert One"</span>); notifyItemInserted(position); } <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">removeData</span>(<span class="hljs-keyword">int</span> position) { mDatas.remove(position); notifyItemRemoved(position); }</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>Activity中点击MenuItem触发：
<code class="language-java hljs has-numbering"> <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">onCreateOptionsMenu</span>(Menu menu) { getMenuInflater().inflate(R.menu.main, menu); <span class="hljs-keyword">return</span> <span class="hljs-keyword">super</span>.onCreateOptionsMenu(menu); } <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">onOptionsItemSelected</span>(MenuItem item) { <span class="hljs-keyword">switch</span> (item.getItemId()) { <span class="hljs-keyword">case</span> R.id.id_action_add: mAdapter.addData(<span class="hljs-number">1</span>); <span class="hljs-keyword">break</span>; <span class="hljs-keyword">case</span> R.id.id_action_delete: mAdapter.removeData(<span class="hljs-number">1</span>); <span class="hljs-keyword">break</span>; } <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>; }</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>好了，到这我对这个控件已经不是一般的喜欢了~~~
当然了只提供了一种动画，那么我们肯定可以去自定义各种nice的动画效果。
高兴的是，github上已经有很多类似的项目了，这里我们直接引用下：RecyclerViewItemAnimators，大家自己下载查看。
提供了SlideInOutLeftItemAnimator,SlideInOutRightItemAnimator,SlideInOutTopItemAnimator,SlideInOutBottomItemAnimator等动画效果。
Click and LongClick
不过一个挺郁闷的地方就是，系统没有提供ClickListener和LongClickListener。
不过我们也可以自己去添加，只是会多了些代码而已。
实现的方式比较多，你可以通过mRecyclerView.addOnItemTouchListener去监听然后去判断手势，
当然你也可以通过adapter中自己去提供回调，这里我们选择后者，前者的方式，大家有兴趣自己去实现。
那么代码也比较简单：
<code class="language-java hljs has-numbering">class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.MyViewHolder>{<span class="hljs-comment">//...</span> <span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">interface</span> <span class="hljs-title">OnItemClickLitener</span> {</span> <span class="hljs-keyword">void</span> onItemClick(View view, <span class="hljs-keyword">int</span> position); <span class="hljs-keyword">void</span> onItemLongClick(View view , <span class="hljs-keyword">int</span> position); } <span class="hljs-keyword">private</span> OnItemClickLitener mOnItemClickLitener; <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setOnItemClickLitener</span>(OnItemClickLitener mOnItemClickLitener) { <span class="hljs-keyword">this</span>.mOnItemClickLitener = mOnItemClickLitener; } <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onBindViewHolder</span>(<span class="hljs-keyword">final</span> MyViewHolder holder, <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> position) { holder.tv.setText(mDatas.get(position)); <span class="hljs-comment">// 如果设置了回调，则设置点击事件</span> <span class="hljs-keyword">if</span> (mOnItemClickLitener != <span class="hljs-keyword">null</span>) { holder.itemView.setOnClickListener(<span class="hljs-keyword">new</span> OnClickListener() { <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onClick</span>(View v) { <span class="hljs-keyword">int</span> pos = holder.getLayoutPosition(); mOnItemClickLitener.onItemClick(holder.itemView, pos); } }); holder.itemView.setOnLongClickListener(<span class="hljs-keyword">new</span> OnLongClickListener() { <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">onLongClick</span>(View v) { <span class="hljs-keyword">int</span> pos = holder.getLayoutPosition(); mOnItemClickLitener.onItemLongClick(holder.itemView, pos); <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>; } }); } }<span class="hljs-comment">//...</span>}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li><li>32</li><li>33</li><li>34</li><li>35</li><li>36</li><li>37</li><li>38</li><li>39</li><li>40</li><li>41</li><li>42</li><li>43</li><li>44</li><li>45</li><li>46</li><li>47</li><li>48</li><li>49</li><li>50</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>adapter中自己定义了个接口，然后在onBindViewHolder中去为holder.itemView去设置相应
的监听最后回调我们设置的监听。
最后别忘了给item添加一个drawable:
<code class="language-xml hljs has-numbering"><span class="hljs-pi"><?xml version="1.0" encoding="utf-8"?></span><span class="hljs-tag"><<span class="hljs-title">selector</span> <span class="hljs-attribute">xmlns:android</span>=<span class="hljs-value">"http://schemas.android.com/apk/res/android"</span> ></span> <span class="hljs-tag"><<span class="hljs-title">item</span> <span class="hljs-attribute">android:state_pressed</span>=<span class="hljs-value">"true"</span> <span class="hljs-attribute">android:drawable</span>=<span class="hljs-value">"@color/color_item_press"</span>></span><span class="hljs-tag"></<span class="hljs-title">item</span>></span> <span class="hljs-tag"><<span class="hljs-title">item</span> <span class="hljs-attribute">android:drawable</span>=<span class="hljs-value">"@color/color_item_normal"</span>></span><span class="hljs-tag"></<span class="hljs-title">item</span>></span><span class="hljs-tag"></<span class="hljs-title">selector</span>></span></code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>
Activity中去设置监听：
<code class="language-java hljs has-numbering"> mAdapter.setOnItemClickLitener(<span class="hljs-keyword">new</span> OnItemClickLitener() { <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onItemClick</span>(View view, <span class="hljs-keyword">int</span> position) { Toast.makeText(HomeActivity.<span class="hljs-keyword">this</span>, position + <span class="hljs-string">" click"</span>, Toast.LENGTH_SHORT).show(); } <span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onItemLongClick</span>(View view, <span class="hljs-keyword">int</span> position) { Toast.makeText(HomeActivity.<span class="hljs-keyword">this</span>, position + <span class="hljs-string">" long click"</span>, Toast.LENGTH_SHORT).show(); mAdapter.removeData(position); } });</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank href="javascript:;" target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" /></a></div>测试效果：
ok，到此我们基本介绍了RecylerView常见用法，包含了：
- 系统提供了几种LayoutManager的使用；
- 如何通过自定义ItemDecoration去设置分割线，或者一些你想作为分隔的drawable，注意这里
巧妙的使用了系统的listDivider属性，你可以尝试添加使用divider和dividerHeight属性。 - 如何使用ItemAnimator为RecylerView去添加Item移除、添加的动画效果。
- 介绍了如何添加ItemClickListener与ItemLongClickListener。
可以看到RecyclerView可以实现：
- ListView的功能
- GridView的功能
- 横向ListView的功能，参考Android 自定义RecyclerView 实现真正的Gallery效果
- 横向ScrollView的功能
- 瀑布流效果
- 便于添加Item增加和移除动画
整个体验下来，感觉这种插拔式的设计太棒了，如果系统再能提供一些常用的分隔符，多添加些动画效果就更好了。
通过简单改变下LayoutManager，就可以产生不同的效果，那么我们可以根据手机屏幕的宽度去动态设置LayoutManager，屏幕宽度一般的，显示为ListView；宽度稍大的显示两列的GridView或者瀑布流（或者横纵屏幕切换时变化，有点意思~）；显示的列数和宽度成正比。甚至某些特殊屏幕，让其横向滑动~~再选择一个nice的动画效果，相信这种插件式的编码体验一定会让你迅速爱上RecyclerView。
参考资料
Android 自定义RecyclerView 实现真正的Gallery效果
A First Glance at Android’s RecyclerView
https://github.com/gabrielemariotti/RecyclerViewItemAnimators
DividerItemDecoration
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