[AS2.2]Behavior使用和自定义RecyclerView万用适配器

有断时间没写了。感觉严重拖沓证又加重了！话说kotlin试了下。做了个Hello Kotlin  到时候发出来记录下吧！还在学习！

本篇是关于Behavior的简单使用和自定义一个Base适配器（资料还是大部分来自网上）

还是先贴gif

随着RecyclerView滚动  隐藏和显示 头尾

目录

1.Behavior的使用

2.自定义Base适配器

1.Behavior的使用

首先来说下behavior吧！首先这个是Material Design系列中加入的

其中最为直观的使用应该是 Material Design系列中使用FloatingActionButton 触发 SnackBar 了

点击之后弹出提示！下面是网上的图

而且 需要注意的是，这个属性只有在外部容器是CoordinatorLayout的时候才能使用

还有就是因为用到了自己设置的toolbar  可以再style中吧默认Theme改成NoAtionBar

styles.xml

<resources>    <!-- Base application theme. -->    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">        <!-- Customize your theme here. -->        <item name="colorPrimary">@color/colorPrimary</item>        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>        <item name="colorAccent">@color/colorAccent</item>    </style></resources>

注意说了下面开始使用吧

先展示布局文件

activity_main.xml

<?xml version="1.0" encoding="utf-8"?><android.support.design.widget.CoordinatorLayout    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    android:layout_width="match_parent"    android:layout_height="match_parent">    <android.support.design.widget.AppBarLayout        android:layout_height="wrap_content"        android:layout_width="match_parent">        <android.support.v7.widget.Toolbar            android:id="@+id/toolbar"            app:layout_scrollFlags="scroll|enterAlways|snap"            android:layout_height="?attr/actionBarSize"            android:layout_width="match_parent">        </android.support.v7.widget.Toolbar>    </android.support.design.widget.AppBarLayout>    <android.support.v7.widget.RecyclerView        app:layout_behavior="@string/appbar_scrolling_view_behavior"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:id="@+id/rv_list" />    <LinearLayout        android:orientation="horizontal"        android:layout_width="match_parent"        android:layout_height="?attr/actionBarSize"        app:layout_behavior="com.gjn.behaviordemo.MyBehavior"        android:id="@+id/ll_tab"        android:background="@android:color/background_light"        android:layout_gravity="bottom">        <Button            android:text="Button"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:id="@+id/button4"            android:layout_weight="1" />        <Button            android:text="Button"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:id="@+id/button3"            android:layout_weight="1" />        <Button            android:text="Button"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:id="@+id/button2"            android:layout_weight="1" />        <Button            android:text="Button"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:id="@+id/button"            android:layout_weight="1" />    </LinearLayout></android.support.design.widget.CoordinatorLayout>

通过上面的布局文件可以看到

在RecyclerView和下面的LinearLayout中都添加了一个属性

app:layout_behavior

其中

RecyclerView是@string/appbar_scrolling_view_behavior 

点进去查看String是 android.support.design.widget.AppBarLayout$ScrollingViewBehavior

LinearLayout是com.gjn.behaviordemo.MyBehavior

上述两个都其实是java类实现的功能

这边来说下MyBehavior的实现

MyBehavior.java

package com.gjn.behaviordemo;import android.content.Context;import android.support.design.widget.AppBarLayout;import android.support.design.widget.CoordinatorLayout;import android.util.AttributeSet;import android.view.View;/** * MyBehavior * Author: gjn. * Time: 2017/5/22. */public class MyBehavior extends CoordinatorLayout.Behavior {    public MyBehavior(Context context, AttributeSet attrs) {        super(context, attrs);    }    @Override    public boolean layoutDependsOn(CoordinatorLayout parent, View child, View dependency) {        return dependency instanceof AppBarLayout;    }    @Override    public boolean onDependentViewChanged(CoordinatorLayout parent, View child, View dependency) {        int delta = dependency.getTop();        child.setTranslationY(-delta);        return true;    }}

代码如上

继承于CoordinatorLayout.Behavior

中间实现了两个方法 layoutDependsOn 和 onDependentViewChanged

从简单的代码 可以看出让整个view都随着AppBarLayout移动

移动-delta Y轴 就实现了开始gif中的整个LinearLayout都向下移动到消失

使用就是 让LinearLayout的behavior属性实现这个方法就可以了！

至此简单的behavior使用就说到这边

2.自定义Base适配器

自定义适配器是为了，减少重复写相同的RecyclerView Adapter代码。虽然RecyclerView Adapter帮我们封装了ViewHolder 但是还是有许多重复的代码

看一下使用自定义适配器的使用吧

        modeladapter = new BaseRecyclerAdapter<Model<Integer>>(this,R.layout.rv_item,modellist) {            @Override            public void bindData(RecyclerViewHolder holder, Model<Integer> item) {                holder.setTextViewText(R.id.tv_name,item.getName());                holder.setTextViewText(R.id.tv_content,item.getContent());                holder.setImageResource(R.id.iv_img,item.getImg());            }        };

只要传入类型  context  item的布局文件 数据list  最后设置下绑定数据就可以了

而且还是多用的。不在需要多次添加Adapter了！

首先我们需要定义一个BaseAdapter和BaseViewHolder

BaseRecyclerAdapter.java

package com.gjn.behaviordemo;import android.content.Context;import android.support.v7.widget.RecyclerView;import android.view.View;import android.view.ViewGroup;import java.util.ArrayList;import java.util.List;/** * BaseRecyclerAdapter * Author: gjn. * Time: 2017/5/2. */public abstract class BaseRecyclerAdapter<T> extends RecyclerView.Adapter<RecyclerViewHolder> {    public interface OnItemClickListener{        void onItemClick(View view,int pos);        void onItemLongClick(View view,int pos);    }    protected List<T> mData;    protected Context mContext;    protected int mLayoutId;    private OnItemClickListener mOnItemClickListener;    public BaseRecyclerAdapter(Context ctx,int layoutId, List<T> list){        mData = (list != null)? list:new ArrayList<T>();        mContext = ctx;        mLayoutId = layoutId;    }    public void setOnItemClickListener(OnItemClickListener listener){        mOnItemClickListener = listener;    }    @Override    public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        final RecyclerViewHolder holder = RecyclerViewHolder.getHolder(mContext,parent,mLayoutId);        if (mOnItemClickListener != null){            holder.itemView.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                    mOnItemClickListener.onItemClick(v,holder.getLayoutPosition());                }            });            holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {                @Override                public boolean onLongClick(View v) {                    mOnItemClickListener.onItemLongClick(v,holder.getLayoutPosition());                    return true;                }            });        }        return holder;    }    @Override    public void onBindViewHolder(RecyclerViewHolder holder, int position) {        bindData(holder,mData.get(position));    }    @Override    public int getItemCount() {        return mData.size();    }    public void add(int pos,T item){        mData.add(pos,item);        notifyItemInserted(pos);    }    public void delete(int pos){        mData.remove(pos);        notifyItemRemoved(pos);    }    public void setData(List<T> list){        mData = list;        notifyDataSetChanged();    }    public void move(int from, int to){        T temp = mData.get(from);        mData.remove(from);        mData.add(to,temp);        notifyItemMoved(from,to);    }    abstract public void bindData(RecyclerViewHolder holder,T item);}

这边我们创建的Base基础类是一个abstract

需要使用者 必须实现的方法是bindData

其他 还设置了点击监听和长按监听

RecyclerViewHolder.java

package com.gjn.behaviordemo;import android.content.Context;import android.graphics.Bitmap;import android.support.v7.widget.RecyclerView;import android.util.SparseArray;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import android.widget.TextView;/** * RecyclerViewHolder * Author: gjn. * Time: 2017/5/2. */public class RecyclerViewHolder extends RecyclerView.ViewHolder {    private final SparseArray<View> mView;    public RecyclerViewHolder(View itemView) {        super(itemView);        mView = new SparseArray<View>();    }    public static RecyclerViewHolder getHolder(Context context, ViewGroup parent,int layoutId){        View view = LayoutInflater.from(context).inflate(layoutId,parent,false);        RecyclerViewHolder holder = new RecyclerViewHolder(view);        return holder;    }    private <T extends View>T findViewById(int id){        View view = mView.get(id);        if (view == null){            view = itemView.findViewById(id);            mView.put(id,view);        }        return (T) view;    }    public View getView(int id){        return findViewById(id);    }    public RecyclerViewHolder setTextViewText(int id,String txt){        TextView textView = (TextView) getView(id);        textView.setText(txt);        return this;    }    public RecyclerViewHolder setImageResource(int id,int resId){        ImageView imageView = (ImageView) getView(id);        imageView.setImageResource(resId);        return this;    }    public RecyclerViewHolder setImageBitmap(int id,Bitmap bm){        ImageView imageView = (ImageView) getView(id);        imageView.setImageBitmap(bm);        return this;    }    public RecyclerViewHolder setViewBackgroundResource(int id,int resId){        View view = getView(id);        view.setBackgroundResource(resId);        return this;    }    public RecyclerViewHolder setClickListener(int id,View.OnClickListener listener){        View view = findViewById(id);        view.setOnClickListener(listener);        return this;    }    public RecyclerViewHolder setLongClickListener(int id, View.OnLongClickListener listener){        View view = findViewById(id);        view.setOnLongClickListener(listener);        return this;    }}

再来是基础ViewHolder的设置

这上面的功能就是简单的一些设置text 设置背景 设置图片 设置监听等等了！

其中findViewById是用来获取个个view的

使用也在上面说了。那么下面就把全部代码贴下吧！

3.全部代码

Model.java

package com.gjn.behaviordemo;/** * Model * Author: gjn. * Time: 2017/5/8. */public class Model<T> {    private String name;    private String content;    private T img;    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getContent() {        return content;    }    public void setContent(String content) {        this.content = content;    }    public T getImg() {        return img;    }    public void setImg(T img) {        this.img = img;    }}

MainActivity.java

package com.gjn.behaviordemo;import android.graphics.Color;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.support.v7.widget.LinearLayoutManager;import android.support.v7.widget.RecyclerView;import android.support.v7.widget.Toolbar;import android.view.View;import android.widget.Toast;import java.util.ArrayList;import java.util.List;public class MainActivity extends AppCompatActivity {    private RecyclerView rv_list;    private List<Model<Integer>> modellist;    private BaseRecyclerAdapter<Model<Integer>> modeladapter;    private Toolbar toolbar;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initview();        initdata();        initclick();    }    private void initclick() {        modeladapter.setOnItemClickListener(new BaseRecyclerAdapter.OnItemClickListener() {            @Override            public void onItemClick(View view, int pos) {                Toast.makeText(MainActivity.this, "点击" + pos, Toast.LENGTH_SHORT).show();            }            @Override            public void onItemLongClick(View view, int pos) {                Toast.makeText(MainActivity.this, "长按" + pos, Toast.LENGTH_SHORT).show();            }        });    }    private void initdata() {        toolbar.setTitle("首页");        toolbar.setTitleTextColor(Color.WHITE);        rv_list.setLayoutManager(new LinearLayoutManager(this));        modellist = new ArrayList<>();        for (int i = 0; i < 20; i++) {            Model<Integer> model = new Model<>();            model.setName("name"+i);            model.setContent("content"+i);            model.setImg(R.mipmap.ic_launcher);            modellist.add(model);        }        modeladapter = new BaseRecyclerAdapter<Model<Integer>>(this,R.layout.rv_item,modellist) {            @Override            public void bindData(RecyclerViewHolder holder, Model<Integer> item) {                holder.setTextViewText(R.id.tv_name,item.getName());                holder.setTextViewText(R.id.tv_content,item.getContent());                holder.setImageResource(R.id.iv_img,item.getImg());            }        };        rv_list.setAdapter(modeladapter);    }    private void initview() {        rv_list = (RecyclerView) findViewById(R.id.rv_list);        toolbar = (Toolbar) findViewById(R.id.toolbar);    }}

rv_item.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:orientation="horizontal"    android:padding="20dp">    <LinearLayout        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_weight="1"        android:orientation="vertical"        android:padding="10dp">        <TextView            android:id="@+id/tv_name"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="TextView"            android:textStyle="normal|bold"            android:textSize="18sp" />        <TextView            android:id="@+id/tv_content"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:paddingTop="5dp"            android:maxLines="1"            android:text="content"            android:paddingRight="5dp" />    </LinearLayout>    <ImageView        android:id="@+id/iv_img"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        app:srcCompat="@mipmap/ic_launcher" /></LinearLayout>