让listview在scrollview中自由滑动

来源：互联网发布：淘宝c店全屏装修编辑：程序博客网时间：2024/05/18 03:40

总有人我listview嵌套scrollview怎么弄。一问就是半天，太耗时，所以写个博客也算是自己总结一下。

目标

scrollview嵌套listview，可以自由的定义listview的大小，而不是展示全部listview。
让listview在scrollview中自由滑动。
当listview滑动到顶端或底端的时候，让scrollview开始滑动

直接上图看效果好了：
这里写图片描述

代码也很简单直接上代码

<code class="hljs xml has-numbering"><span class="hljs-pi"><?xml version="1.0" encoding="utf-8"?></span><span class="hljs-tag"><<span class="hljs-title">ScrollView</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">"wrap_content"</span>    <span class="hljs-attribute">android:background</span>=<span class="hljs-value">"@color/colorPrimary"</span>    <span class="hljs-attribute">android:paddingBottom</span>=<span class="hljs-value">"@dimen/activity_vertical_margin"</span>    <span class="hljs-attribute">android:paddingLeft</span>=<span class="hljs-value">"@dimen/activity_horizontal_margin"</span>    <span class="hljs-attribute">android:paddingRight</span>=<span class="hljs-value">"@dimen/activity_horizontal_margin"</span>    <span class="hljs-attribute">android:paddingTop</span>=<span class="hljs-value">"@dimen/activity_vertical_margin"</span>    <span class="hljs-attribute">tools:context</span>=<span class="hljs-value">"wang.com.scrollholdlistview.MainActivity"</span>></span>    <span class="hljs-tag"><<span class="hljs-title">LinearLayout</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">"wrap_content"</span>        <span class="hljs-attribute">android:orientation</span>=<span class="hljs-value">"vertical"</span>></span>        <span class="hljs-tag"><<span class="hljs-title">TextView</span>            <span class="hljs-attribute">android:layout_width</span>=<span class="hljs-value">"wrap_content"</span>            <span class="hljs-attribute">android:layout_height</span>=<span class="hljs-value">"wrap_content"</span>            <span class="hljs-attribute">android:layout_margin</span>=<span class="hljs-value">"@dimen/activity_vertical_margin"</span>            <span class="hljs-attribute">android:text</span>=<span class="hljs-value">"Hello World!"</span>            <span class="hljs-attribute">android:textSize</span>=<span class="hljs-value">"30sp"</span> /></span>        <span class="hljs-tag"><<span class="hljs-title">TextView</span>            <span class="hljs-attribute">android:layout_width</span>=<span class="hljs-value">"wrap_content"</span>            <span class="hljs-attribute">android:layout_height</span>=<span class="hljs-value">"wrap_content"</span>            <span class="hljs-attribute">android:layout_margin</span>=<span class="hljs-value">"@dimen/activity_vertical_margin"</span>            <span class="hljs-attribute">android:text</span>=<span class="hljs-value">"Hello World!"</span>            <span class="hljs-attribute">android:textSize</span>=<span class="hljs-value">"30sp"</span> /></span>        <span class="hljs-tag"><<span class="hljs-title">TextView</span>            <span class="hljs-attribute">android:layout_width</span>=<span class="hljs-value">"wrap_content"</span>            <span class="hljs-attribute">android:layout_height</span>=<span class="hljs-value">"wrap_content"</span>            <span class="hljs-attribute">android:layout_margin</span>=<span class="hljs-value">"@dimen/activity_vertical_margin"</span>            <span class="hljs-attribute">android:text</span>=<span class="hljs-value">"Hello World!"</span>            <span class="hljs-attribute">android:textSize</span>=<span class="hljs-value">"30sp"</span> /></span>        <span class="hljs-tag"><<span class="hljs-title">TextView</span>            <span class="hljs-attribute">android:layout_width</span>=<span class="hljs-value">"wrap_content"</span>            <span class="hljs-attribute">android:layout_height</span>=<span class="hljs-value">"wrap_content"</span>            <span class="hljs-attribute">android:layout_margin</span>=<span class="hljs-value">"@dimen/activity_vertical_margin"</span>            <span class="hljs-attribute">android:text</span>=<span class="hljs-value">"Hello World!"</span>            <span class="hljs-attribute">android:textSize</span>=<span class="hljs-value">"30sp"</span> /></span>        <span class="hljs-tag"><<span class="hljs-title">wang.com.scrollholdlistview.MyListView</span>            <span class="hljs-attribute">android:id</span>=<span class="hljs-value">"@+id/lv"</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">"400dp"</span>            <span class="hljs-attribute">android:background</span>=<span class="hljs-value">"@color/colorAccent"</span>></span><span class="hljs-tag"></<span class="hljs-title">wang.com.scrollholdlistview.MyListView</span>></span>        <span class="hljs-tag"><<span class="hljs-title">TextView</span>            <span class="hljs-attribute">android:layout_width</span>=<span class="hljs-value">"wrap_content"</span>            <span class="hljs-attribute">android:layout_height</span>=<span class="hljs-value">"wrap_content"</span>            <span class="hljs-attribute">android:layout_margin</span>=<span class="hljs-value">"@dimen/activity_vertical_margin"</span>            <span class="hljs-attribute">android:text</span>=<span class="hljs-value">"Hello World!"</span>            <span class="hljs-attribute">android:textSize</span>=<span class="hljs-value">"30sp"</span> /></span>        <span class="hljs-tag"><<span class="hljs-title">TextView</span>            <span class="hljs-attribute">android:layout_width</span>=<span class="hljs-value">"wrap_content"</span>            <span class="hljs-attribute">android:layout_height</span>=<span class="hljs-value">"wrap_content"</span>            <span class="hljs-attribute">android:layout_margin</span>=<span class="hljs-value">"@dimen/activity_vertical_margin"</span>            <span class="hljs-attribute">android:text</span>=<span class="hljs-value">"Hello World!"</span>            <span class="hljs-attribute">android:textSize</span>=<span class="hljs-value">"30sp"</span> /></span>        <span class="hljs-tag"><<span class="hljs-title">TextView</span>            <span class="hljs-attribute">android:layout_width</span>=<span class="hljs-value">"wrap_content"</span>            <span class="hljs-attribute">android:layout_height</span>=<span class="hljs-value">"wrap_content"</span>            <span class="hljs-attribute">android:layout_margin</span>=<span class="hljs-value">"@dimen/activity_vertical_margin"</span>            <span class="hljs-attribute">android:text</span>=<span class="hljs-value">"Hello World!"</span>            <span class="hljs-attribute">android:textSize</span>=<span class="hljs-value">"30sp"</span> /></span>        <span class="hljs-tag"><<span class="hljs-title">wang.com.scrollholdlistview.MyListView</span>            <span class="hljs-attribute">android:id</span>=<span class="hljs-value">"@+id/lv1"</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">"wrap_content"</span>            <span class="hljs-attribute">android:background</span>=<span class="hljs-value">"@color/colorAccent"</span>></span>        <span class="hljs-tag"></<span class="hljs-title">wang.com.scrollholdlistview.MyListView</span>></span>    <span class="hljs-tag"></<span class="hljs-title">LinearLayout</span>></span><span class="hljs-tag"></<span class="hljs-title">ScrollView</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><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 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<code class="hljs java has-numbering"><span class="hljs-keyword">package</span> wang.com.scrollholdlistview;<span class="hljs-keyword">import</span> android.content.Context;<span class="hljs-keyword">import</span> android.util.AttributeSet;<span class="hljs-keyword">import</span> android.util.Log;<span class="hljs-keyword">import</span> android.view.MotionEvent;<span class="hljs-keyword">import</span> android.widget.ListView;<span class="hljs-javadoc">/** * 创建日期: 16/4/3 下午9:55 * 作者:wanghao * 描述: */</span><span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">MyListView</span> <span class="hljs-keyword">extends</span> <span class="hljs-title">ListView</span> {</span>    <span class="hljs-keyword">private</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">final</span> String TAG = <span class="hljs-string">"MyListView"</span>;    <span class="hljs-keyword">public</span> <span class="hljs-title">MyListView</span>(Context context) {        <span class="hljs-keyword">this</span>(context, <span class="hljs-keyword">null</span>);    }    <span class="hljs-keyword">public</span> <span class="hljs-title">MyListView</span>(Context context, AttributeSet attrs) {        <span class="hljs-keyword">this</span>(context, attrs, <span class="hljs-number">0</span>);    }    <span class="hljs-keyword">public</span> <span class="hljs-title">MyListView</span>(Context context, AttributeSet attrs, <span class="hljs-keyword">int</span> defStyleAttr) {        <span class="hljs-keyword">super</span>(context, attrs, defStyleAttr);    }    <span class="hljs-annotation">@Override</span>    <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onMeasure</span>(<span class="hljs-keyword">int</span> widthMeasureSpec, <span class="hljs-keyword">int</span> heightMeasureSpec) {        <span class="hljs-keyword">int</span> defaultsize=measureHight(Integer.MAX_VALUE >> <span class="hljs-number">2</span>, heightMeasureSpec);        <span class="hljs-keyword">int</span> expandSpec = MeasureSpec.makeMeasureSpec(defaultsize, MeasureSpec.AT_MOST);        <span class="hljs-keyword">super</span>.onMeasure(widthMeasureSpec, expandSpec);    }    <span class="hljs-keyword">private</span> <span class="hljs-keyword">int</span> <span class="hljs-title">measureHight</span>(<span class="hljs-keyword">int</span> size, <span class="hljs-keyword">int</span> measureSpec) {        <span class="hljs-keyword">int</span> result = <span class="hljs-number">0</span>;        <span class="hljs-keyword">int</span> specMode = MeasureSpec.getMode(measureSpec);        <span class="hljs-keyword">int</span> specSize = MeasureSpec.getSize(measureSpec);        <span class="hljs-keyword">if</span> (specMode == MeasureSpec.EXACTLY) {            Log.i(TAG, <span class="hljs-string">"exactly"</span> );            result = specSize;        } <span class="hljs-keyword">else</span> {            result = size;<span class="hljs-comment">//最小值是200px ，自己设定</span>            <span class="hljs-keyword">if</span> (specMode == MeasureSpec.AT_MOST) {                result = Math.min(result, specSize);            }            Log.i(TAG, <span class="hljs-string">"specMode:"</span>+specMode+<span class="hljs-string">"--result:"</span>+result );        }        <span class="hljs-keyword">return</span> result;    }    <span class="hljs-javadoc">/**     * 改listview滑到底端了     *     *<span class="hljs-javadoctag"> @return</span>     */</span>    <span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">isBottom</span>() {        <span class="hljs-keyword">int</span> firstVisibleItem = getFirstVisiblePosition();<span class="hljs-comment">//屏幕上显示的第一条是list中的第几条</span>        <span class="hljs-keyword">int</span> childcount = getChildCount();<span class="hljs-comment">//屏幕上显示多少条item</span>        <span class="hljs-keyword">int</span> totalItemCount = getCount();<span class="hljs-comment">//一共有多少条</span>        <span class="hljs-keyword">if</span> ((firstVisibleItem + childcount) >=totalItemCount) {            <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-javadoc">/**     * 改listview在顶端     *     *<span class="hljs-javadoctag"> @return</span>     */</span>    <span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">isTop</span>() {        <span class="hljs-keyword">int</span> firstVisibleItem = getFirstVisiblePosition();        <span class="hljs-keyword">if</span> (firstVisibleItem ==<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-keyword">float</span> down = <span class="hljs-number">0</span>;    <span class="hljs-keyword">float</span> y;    <span class="hljs-annotation">@Override</span>    <span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">dispatchTouchEvent</span>(MotionEvent event) {        <span class="hljs-keyword">switch</span> (event.getAction()) {            <span class="hljs-keyword">case</span> MotionEvent.ACTION_DOWN:                down = event.getRawY();                getParent().requestDisallowInterceptTouchEvent(<span class="hljs-keyword">true</span>);                <span class="hljs-keyword">break</span>;            <span class="hljs-keyword">case</span> MotionEvent.ACTION_MOVE:                y = event.getRawY();                <span class="hljs-keyword">if</span> (isTop()) {                    <span class="hljs-keyword">if</span> (y - down > <span class="hljs-number">1</span>) {<span class="hljs-comment">//                        到顶端,向下滑动 把事件教给父类</span>                        getParent().requestDisallowInterceptTouchEvent(<span class="hljs-keyword">false</span>);                    } <span class="hljs-keyword">else</span> {                        <span class="hljs-comment">//                        到顶端,向上滑动 把事件拦截 由自己处理</span>                        getParent().requestDisallowInterceptTouchEvent(<span class="hljs-keyword">true</span>);                    }                }                <span class="hljs-keyword">if</span> (isBottom()) {                    <span class="hljs-keyword">if</span> (y - down > <span class="hljs-number">1</span>) {<span class="hljs-comment">//                        到底端,向下滑动 把事件拦截 由自己处理</span>                        getParent().requestDisallowInterceptTouchEvent(<span class="hljs-keyword">true</span>);                    } <span class="hljs-keyword">else</span> {<span class="hljs-comment">//                        到底端,向上滑动 把事件教给父类</span>                        getParent().requestDisallowInterceptTouchEvent(<span class="hljs-keyword">false</span>);                    }                }                <span class="hljs-keyword">break</span>;            <span class="hljs-keyword">default</span>:                <span class="hljs-keyword">break</span>;        }        <span class="hljs-keyword">return</span> <span class="hljs-keyword">super</span>.dispatchTouchEvent(event);    }}</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></ul><div class="save_code tracking-ad" style="display: none;" data-mod="popu_249"><a target=_blank target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" alt="" /></a></div>

上面代码直接用就可以啦。
那么下面说下好多人遇到过的疑惑

为什么这么写就能避免嵌套问题呢
下面代码是网上流传最多的

<code class="hljs java has-numbering"><span class="hljs-annotation">@Override</span><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onMeasure</span>(<span class="hljs-keyword">int</span> widthMeasureSpec, <span class="hljs-keyword">int</span> heightMeasureSpec) {<span class="hljs-keyword">int</span> expandSpec = MeasureSpec.makeMeasureSpec(            Integer.MAX_VALUE >> <span class="hljs-number">2</span>, MeasureSpec.AT_MOST);    <span class="hljs-keyword">super</span>.onMeasure(widthMeasureSpec, expandSpec);}</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></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" alt="" /></a></div>

这样写呢有个弊端，就是在scrollview里面展示了 listview的全部内容。有100条就显示了100条。
Integer.MAX_VALUE >> 2这个呢就是一个值。让你的listview最大值是多大。你可以写成65535，或者其他数值。为什么用 MeasureSpec.AT_MOST呢？
看下super里面

<code class="hljs java has-numbering"><span class="hljs-annotation">@Override</span>    <span class="hljs-keyword">protected</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onMeasure</span>(<span class="hljs-keyword">int</span> widthMeasureSpec, <span class="hljs-keyword">int</span> heightMeasureSpec) {        <span class="hljs-comment">// Sets up mListPadding</span>        <span class="hljs-keyword">super</span>.onMeasure(widthMeasureSpec, heightMeasureSpec);        <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> widthMode = MeasureSpec.getMode(widthMeasureSpec);        <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> heightMode = MeasureSpec.getMode(heightMeasureSpec);        <span class="hljs-keyword">int</span> widthSize = MeasureSpec.getSize(widthMeasureSpec);        <span class="hljs-keyword">int</span> heightSize = MeasureSpec.getSize(heightMeasureSpec);       ...        <span class="hljs-keyword">if</span> (heightMode == MeasureSpec.AT_MOST) {            <span class="hljs-comment">// TODO: after first layout we should maybe start at the first visible position, not 0</span>            heightSize = measureHeightOfChildren(widthMeasureSpec, <span class="hljs-number">0</span>, NO_POSITION, heightSize, -<span class="hljs-number">1</span>);        }        setMeasuredDimension(widthSize, heightSize);        mWidthMeasureSpec = widthMeasureSpec;    }</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 target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" alt="" /></a></div>

再看下measureHeightOfChildren（）的内容

<code class="hljs java has-numbering"><span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> measureHeightOfChildren(<span class="hljs-keyword">int</span> widthMeasureSpec, <span class="hljs-keyword">int</span> startPosition, <span class="hljs-keyword">int</span> endPosition,            <span class="hljs-keyword">int</span> maxHeight, <span class="hljs-keyword">int</span> disallowPartialChildPosition) {        <span class="hljs-keyword">final</span> ListAdapter adapter = mAdapter;        <span class="hljs-keyword">if</span> (adapter == <span class="hljs-keyword">null</span>) {            <span class="hljs-keyword">return</span> mListPadding.top + mListPadding.bottom;        }        <span class="hljs-comment">// Include the padding of the list</span>        <span class="hljs-keyword">int</span> returnedHeight = mListPadding.top + mListPadding.bottom;        <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> dividerHeight = ((mDividerHeight > <span class="hljs-number">0</span>) && mDivider != <span class="hljs-keyword">null</span>) ? mDividerHeight : <span class="hljs-number">0</span>;        <span class="hljs-comment">// The previous height value that was less than maxHeight and contained</span>        <span class="hljs-comment">// no partial children</span>        <span class="hljs-keyword">int</span> prevHeightWithoutPartialChild = <span class="hljs-number">0</span>;        <span class="hljs-keyword">int</span> i;        View child;        <span class="hljs-comment">// mItemCount - 1 since endPosition parameter is inclusive</span>        endPosition = (endPosition == NO_POSITION) ? adapter.getCount() - <span class="hljs-number">1</span> : endPosition;<span class="hljs-comment">//获取有多少个item</span>        <span class="hljs-keyword">final</span> AbsListView.RecycleBin recycleBin = mRecycler;        <span class="hljs-keyword">final</span> <span class="hljs-keyword">boolean</span> recyle = recycleOnMeasure();        <span class="hljs-keyword">final</span> <span class="hljs-keyword">boolean</span>[] isScrap = mIsScrap;<span class="hljs-comment">//遍历所有item并且 获取到 所有item的整体高度</span>        <span class="hljs-keyword">for</span> (i = startPosition; i <= endPosition; ++i) {            child = obtainView(i, isScrap);            measureScrapChild(child, i, widthMeasureSpec, maxHeight);            <span class="hljs-keyword">if</span> (i > <span class="hljs-number">0</span>) {                <span class="hljs-comment">// Count the divider for all but one child</span>                returnedHeight += dividerHeight;            }            <span class="hljs-comment">// Recycle the view before we possibly return from the method</span>            <span class="hljs-keyword">if</span> (recyle && recycleBin.shouldRecycleViewType(                    ((LayoutParams) child.getLayoutParams()).viewType)) {                recycleBin.addScrapView(child, -<span class="hljs-number">1</span>);            }            returnedHeight += child.getMeasuredHeight();<span class="hljs-comment">//如果item的高度大于咱们赋值的高度也就是Integer.MAX_VALUE >> 2 </span>            <span class="hljs-keyword">if</span> (returnedHeight >= maxHeight) {                <span class="hljs-comment">// We went over, figure out which height to return.  If returnedHeight > maxHeight,</span>                <span class="hljs-comment">// then the i'th position did not fit completely.</span>                <span class="hljs-keyword">return</span> (disallowPartialChildPosition >= <span class="hljs-number">0</span>) <span class="hljs-comment">// Disallowing is enabled (> -1)</span>                            && (i > disallowPartialChildPosition) <span class="hljs-comment">// We've past the min pos</span>                            && (prevHeightWithoutPartialChild > <span class="hljs-number">0</span>) <span class="hljs-comment">// We have a prev height</span>                            && (returnedHeight != maxHeight) <span class="hljs-comment">// i'th child did not fit completely</span>                        ? prevHeightWithoutPartialChild 如果是大于就用自己item整体的高度作为listview的高度                        : maxHeight; 如果是等于那么久用 我们赋值的高度            }<span class="hljs-comment">//如果item的高度 不大于等于 默认值 那么久显示他自己的高度了 </span>            <span class="hljs-keyword">if</span> ((disallowPartialChildPosition >= <span class="hljs-number">0</span>) && (i >= disallowPartialChildPosition)) {                prevHeightWithoutPartialChild = returnedHeight;            }        }        <span class="hljs-comment">// At this point, we went through the range of children, and they each</span>        <span class="hljs-comment">// completely fit, so return the returnedHeight</span>        <span class="hljs-keyword">return</span> returnedHeight;    }</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></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" alt="" /></a></div>

所以我们赋值的Integer.MAX_VALUE >> 2只是一个参考值，你想写多少就是多少。
但是那样写有个弊端就是在xml里面写的高度就没用了。所以我们就这么写了

<code class="hljs java has-numbering">  <span class="hljs-annotation">@Override</span>    <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onMeasure</span>(<span class="hljs-keyword">int</span> widthMeasureSpec, <span class="hljs-keyword">int</span> heightMeasureSpec) {        <span class="hljs-keyword">int</span> defaultsize=measureHight(Integer.MAX_VALUE >> <span class="hljs-number">2</span>, heightMeasureSpec);        <span class="hljs-keyword">int</span> expandSpec = MeasureSpec.makeMeasureSpec(defaultsize, MeasureSpec.AT_MOST);        <span class="hljs-keyword">super</span>.onMeasure(widthMeasureSpec, expandSpec);    }    <span class="hljs-keyword">private</span> <span class="hljs-keyword">int</span> <span class="hljs-title">measureHight</span>(<span class="hljs-keyword">int</span> size, <span class="hljs-keyword">int</span> measureSpec) {        <span class="hljs-keyword">int</span> result = <span class="hljs-number">0</span>;        <span class="hljs-keyword">int</span> specMode = MeasureSpec.getMode(measureSpec);        <span class="hljs-keyword">int</span> specSize = MeasureSpec.getSize(measureSpec);        <span class="hljs-keyword">if</span> (specMode == MeasureSpec.EXACTLY) {            Log.i(TAG, <span class="hljs-string">"exactly"</span> );            result = specSize;        } <span class="hljs-keyword">else</span> {            result = size;<span class="hljs-comment">//最小值是200px ，自己设定</span>            <span class="hljs-keyword">if</span> (specMode == MeasureSpec.AT_MOST) {                result = Math.min(result, specSize);            }            Log.i(TAG, <span class="hljs-string">"specMode:"</span>+specMode+<span class="hljs-string">"--result:"</span>+result );        }        <span class="hljs-keyword">return</span> result;    }</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></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" alt="" /></a></div>

这样的话就是如果 xml里面是wrap_content的话就显示所有item的高度。如果是设置了高度值比如是400dp。那么listview显示的高度就是400dp。
为什么那么些请戳这尼自定义view，viewgroup的onMeasure 方法

那么问题又来了。
如果显示400dp的高度。listview就没法全部显示了。
所以就不能让scrollview拦截事件，要让该事件传递到listview，并且处理。一行代码就搞定

<code class="hljs bash has-numbering">  getParent().requestDisallowInterceptTouchEvent(<span class="hljs-literal">true</span>);  <span class="hljs-literal">true</span>：就是拦截此事件  <span class="hljs-literal">false</span>：不拦截此事件，让父类处理</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li></ul><div class="save_code tracking-ad" data-mod="popu_249"><a target=_blank target="_blank"><img src="http://static.blog.csdn.net/images/save_snippets.png" alt="" /></a></div>

剩下的就只是当listview滑动到顶端和底端 listview就拦截该事件了。代码里已经体现的很简单了。
尊重原创：http://blog.csdn.net/wanghao200906/article/details/51084975
代码在这里

最近太忙了。发个福利安慰一下自己
这里写图片描述

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