RecyclerView

控件简单介绍

  • ListView的升级版
  • LinearLayoutManager
  • GridLayoutManager
  • StaggeredGridLayoutManager
  • 定制Item动画，指定Item之间的分隔线

RecyclerView相关的重要类

  • Adapter
  • ViewHolder
  • LayoutManager
  • ItemDecoration
  • ItemAnimator

加入RecyclerView控件依赖包

Android Studio开发工具，在本项目的build.gradle文件里加入

  compile 'com.android.support:recyclerview-v7:23.1.1'

假设是eclipse的话，下载jar包。放到lib下。一般都会自己主动的build path,检查下就可以。

怎样下载jar ?

在SDK Manager中下载Support Library

sdk\extras\android\support\v7\recyclerview\libs

为Recycler准备数据

package demo.turing.com.materialdesignwidget.recyclerView;

import java.util.ArrayList;

import demo.turing.com.materialdesignwidget.recyclerView.model.SampleModel;

/**

 * MyApp

 *

 * @author Mr.Yang on 2016-03-30  20:21.

 * @version 1.0

 * @desc

 */

public class SimulatorData {

    public static ArrayList<SampleModel> getSampleModelData(int size) {

        ArrayList<SampleModel> sampleData = new ArrayList<SampleModel>(size);

        for (int i = 0; i < size; i++) {

            sampleData.add(new SampleModel("新的列表项< " + i + " >"));

        }

        return sampleData;

    }

}


package demo.turing.com.materialdesignwidget.recyclerView.model;

/**

 * MyApp

 *

 * @author Mr.Yang on 2016-03-30  20:23.

 * @version 1.0

 * 相应Item中药显示的数据项

 */

public class SampleModel {

    private String text;

    public SampleModel(String text) {

        this.text = text;

    }

    public String getText() {

        return text;

    }

    public void setText(String text) {

        this.text = text;

    }

}

绘制列表项之间的分隔线

package demo.turing.com.materialdesignwidget.recyclerView;

import android.content.Context;

import android.content.res.TypedArray;

import android.graphics.Canvas;

import android.graphics.Rect;

import android.graphics.drawable.Drawable;

import android.support.v7.widget.LinearLayoutManager;

import android.support.v7.widget.RecyclerView;

import android.view.View;

/**

 * MyApp

 *

 * @author Mr.Yang on 2016-03-30  20:37.

 * @version 1.0

 *          分隔条

 *

 *

 *   DividerItemDecoration  https://gist.github.com/alexfu/0f464fc3742f134ccd1e

 */

public class DividerItemDecoration extends RecyclerView.ItemDecoration {

    // 默认分隔条Drawable资源的ID,使用系统自带的

    private static final int[] ATTRS = new int[]{android.R.attr.listDivider};

    public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;

    public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;

    private Drawable mDivider;

    private int mOrientation;

    public DividerItemDecoration(Context context, int orientation) {

        // 使用TypedArray装载定义的ATTRS

        final TypedArray a = context.obtainStyledAttributes(ATTRS);

        // 获取系统提供的分隔条Drawable对象

        mDivider = a.getDrawable(0);

        // 回收TypedArray所占用的空间

        a.recycle();

        setOrientation(orientation);

    }

    /**

     * 设置item的显示 水平 or 垂直

     *

     * @param orientation

     */

    public void setOrientation(int orientation) {

        if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {

            throw new IllegalArgumentException("invalid orientation");

        }

        mOrientation = orientation;

    }

    @Override

    public void onDraw(Canvas c, RecyclerView parent) {

        if (mOrientation == VERTICAL_LIST) {

            drawVertical(c, parent);

        } else {

            drawHorizontal(c, parent);

        }

    }

    public void drawVertical(Canvas c, RecyclerView parent) {

        final int left = parent.getPaddingLeft();

        final int right = parent.getWidth() - parent.getPaddingRight();

        final int childCount = parent.getChildCount();

        for (int i = 0; i < childCount; i++) {

            final View child = parent.getChildAt(i);

            RecyclerView v = new android.support.v7.widget.RecyclerView(

                    parent.getContext());

            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child

                    .getLayoutParams();

            final int top = child.getBottom() + params.bottomMargin;

            final int bottom = top + mDivider.getIntrinsicHeight();

            mDivider.setBounds(left, top, right, bottom);

            mDivider.draw(c);

        }

    }

    public void drawHorizontal(Canvas c, RecyclerView parent) {

        final int top = parent.getPaddingTop();

        final int bottom = parent.getHeight() - parent.getPaddingBottom();

        final int childCount = parent.getChildCount();

        for (int i = 0; i < childCount; i++) {

            final View child = parent.getChildAt(i);

            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child

                    .getLayoutParams();

            final int left = child.getRight() + params.rightMargin;

            final int right = left + mDivider.getIntrinsicHeight();

            mDivider.setBounds(left, top, right, bottom);

            mDivider.draw(c);

        }

    }

    @Override

    public void getItemOffsets(Rect outRect, int itemPosition,

                               RecyclerView parent) {

        if (mOrientation == VERTICAL_LIST) {

            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());

        } else {

            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);

        }

    }

}

实现Adapter

package demo.turing.com.materialdesignwidget.recyclerView.adapter;

import android.support.v7.widget.RecyclerView;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.TextView;

import java.util.ArrayList;

import java.util.Random;

import demo.turing.com.materialdesignwidget.R;

import demo.turing.com.materialdesignwidget.recyclerView.SimulatorData;

import demo.turing.com.materialdesignwidget.recyclerView.model.SampleModel;

/**

 * MyApp

 *

 * @author Mr.Yang on 2016-03-30  21:03.

 * @version 1.0

 * @desc

 */

public class SampleRecyclerAdapter extends RecyclerView.Adapter<SampleRecyclerAdapter.ViewHolder> {

    // 模拟数据

    private  ArrayList<SampleModel> sampleData = SimulatorData.getSampleModelData(20);

    /**

     * 用于创建控件

     *

     * @param parent

     * @param viewType

     * @return

     */

    @Override

    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        // 获得列表项控件（LinearLayer对象）

        // list_basic_item.xml布局文件里仅仅包括一个<LinearLayer>标签，

        // 在该标签中包括了一个<TextView>标签, item是LinearLayout对象

        View item = LayoutInflater.from(parent.getContext()).inflate(

                R.layout.list_basic_item, parent, false);

        ViewHolder viewHolder = new ViewHolder(item);

        return viewHolder;

    }

    /**

     * 为控件设置数据

     *

     * @param holder

     * @param position

     */

    @Override

    public void onBindViewHolder(ViewHolder holder, int position) {

        //  获取当前item中显示的数据

        final SampleModel rowData = sampleData.get(position);

        //  设置要显示的数据

        holder.textViewSample.setText(rowData.getText());

        // 设置tag

        holder.itemView.setTag(rowData);

    }

    @Override

    public int getItemCount() {

        return sampleData.size();

    }

    /**

     * 删除指定的Item

     *

     * @param position

     */

    public void removeData(int position) {

        sampleData.remove(position);

        //  通知RecyclerView控件某个Item已经被删除

        notifyItemRemoved(position);

    }

    /**

     * 在指定位置加入一个新的Item

     *

     * @param positionToAdd

     */

    public void addItem(int positionToAdd) {

        sampleData.add(positionToAdd, new SampleModel("新的列表项" + new Random().nextInt(10000)));

        //  通知RecyclerView控件插入了某个Item

        notifyItemInserted(positionToAdd);

    }

    /**

     * 相应Item中的控件

     */

    public static class ViewHolder extends RecyclerView.ViewHolder {

        private final TextView textViewSample;

        public ViewHolder(View itemView) {

            super(itemView);

            textViewSample = (TextView) itemView

                    .findViewById(R.id.textViewSample);

        }

    }

}

完毕使用RecyclerView控件的最后工作

package demo.turing.com.materialdesignwidget.recyclerView;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.support.v7.widget.LinearLayoutManager;

import android.support.v7.widget.RecyclerView;

import demo.turing.com.materialdesignwidget.R;

import demo.turing.com.materialdesignwidget.recyclerView.adapter.SampleRecyclerAdapter;

public class RecyclerViewAct extends AppCompatActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_recycler_view);

        // 获取RecyclerView对象

        RecyclerView recyclerView = (RecyclerView)findViewById(R.id.recycler_view);

        //  创建线性布局管理器（默认是垂直方向）

        LinearLayoutManager layoutManager = new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false);

        //  为RecyclerView指定布局管理对象

        recyclerView.setLayoutManager(layoutManager);

        //  创建列表项分隔线对象

        RecyclerView.ItemDecoration itemDecoration = new DividerItemDecoration(this,DividerItemDecoration.VERTICAL_LIST);

        //  为RecyclerView控件指定分隔线对象

        recyclerView.addItemDecoration(itemDecoration);

        SampleRecyclerAdapter sampleRecyclerAdapter = new SampleRecyclerAdapter();

        recyclerView.setAdapter(sampleRecyclerAdapter);

    }

}

效果图

定制个性化分隔条

drawable\divider_custom.xml

<?xml version="1.0" encoding="utf-8"?>

<shape xmlns:android="http://schemas.android.com/apk/res/android"

    android:shape="rectangle">

    <size android:height="4dp"></size>

    <!--渐变色-->

    <gradient

        android:centerColor="#ff0000ff"

        android:endColor="#ffff0000"

        android:startColor="#ffff0000"

        android:type="linear"></gradient>

</shape>

主题中设置

  <item name="android:listDivider">@drawable/divider_custom</item>

瀑布流

StaggeredGridLayuoutAct.java

package demo.turing.com.materialdesignwidget.recyclerView;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.support.v7.widget.RecyclerView;

import android.support.v7.widget.StaggeredGridLayoutManager;

import java.util.List;

import demo.turing.com.materialdesignwidget.R;

import demo.turing.com.materialdesignwidget.recyclerView.adapter.StaggeredGridLayoutAdapter;

import demo.turing.com.materialdesignwidget.recyclerView.model.SampleModel;

/**

 * 不採用分隔线， 在Item的布局中 採用layout_margin的方式

 *

 * 主要是动态设置View的高度 adapter类中的 onBindViewHolder

 */

public class StaggeredGridLayuoutAct extends AppCompatActivity {

    private RecyclerView recyclerView ;

    // 模拟数据

    private List<SampleModel> sampleData = SimulatorData.getSampleModelData(20);

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_staggered_grid_layuout);

        // 查找组件

        recyclerView = (RecyclerView) findViewById(R.id.id_rv_staggered);

        // 创建布局管理器  -3列，垂直

        StaggeredGridLayoutManager manager = new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL);

        // 设置布局

        recyclerView.setLayoutManager(manager);

        // Adapter

        StaggeredGridLayoutAdapter adapter = new StaggeredGridLayoutAdapter(this,sampleData);

        recyclerView.setAdapter(adapter);

    }

}

activity_staggered_grid_layuout.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context="demo.turing.com.materialdesignwidget.recyclerView.StaggeredGridLayuoutAct">

    <android.support.v7.widget.RecyclerView

        android:id="@+id/id_rv_staggered"

        android:layout_width="match_parent"

        android:layout_height="match_parent"></android.support.v7.widget.RecyclerView>

</RelativeLayout>

StaggeredGridLayoutAdapter.java

package demo.turing.com.materialdesignwidget.recyclerView.adapter;

import android.content.Context;

import android.support.v7.widget.RecyclerView;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.TextView;

import java.util.ArrayList;

import java.util.List;

import demo.turing.com.materialdesignwidget.R;

import demo.turing.com.materialdesignwidget.recyclerView.model.SampleModel;

/**

 * MyApp

 *

 * @author Mr.Yang on 2016-03-31  20:19.

 * @version 1.0

 * @desc

 */

public class StaggeredGridLayoutAdapter extends RecyclerView.Adapter<StaggeredGridLayoutAdapter.ViewHolder> {

    private Context context;

    private List<SampleModel> datas;

    private LayoutInflater inflater;

    // 随机高度的结合

    private List<Integer> mHeights;

    /**

     * 构造函数

     *

     * @param context

     * @param datas

     */

    public StaggeredGridLayoutAdapter(Context context, List<SampleModel> datas) {

        this.context = context;

        this.datas = datas;

        this.inflater = LayoutInflater.from(context);

        // 初始化随机高度的集合

        mHeights = new ArrayList<>();

        for (int i = 0; i < datas.size(); i++) {

            mHeights.add((int)(100 + Math.random() * 300));

        }

    }

    @Override

    public StaggeredGridLayoutAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        // 动态载入Item的布局文件

        View view = inflater.inflate(R.layout.list_basic_item, parent, false);

        // 实例化ViewHolder

        ViewHolder viewHolder = new ViewHolder(view);

        return viewHolder;

    }

    @Override

    public void onBindViewHolder(StaggeredGridLayoutAdapter.ViewHolder holder, int position) {

        // 获取当前Item中的显示的数据

        SampleModel sampleModel = datas.get(position);

        //设置控件的随机高度

        ViewGroup.LayoutParams lp = holder.itemView.getLayoutParams();

        lp.height = mHeights.get(position);

        holder.itemView.setLayoutParams(lp);

        // 设置组件的值

        holder.textView.setText(sampleModel.getText());

        // 设置tag

        holder.itemView.setTag(sampleModel);

    }

    @Override

    public int getItemCount() {

        return datas.size();

    }

    /**

     * ViewHoder

     */

    class ViewHolder extends RecyclerView.ViewHolder {

        TextView textView;

        public ViewHolder(View itemView) {

            super(itemView);

            textView = (TextView) itemView

                    .findViewById(R.id.textViewSample);

        }

    }

}

list_basic_item.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:layout_margin="3dp"

    android:background="#6495ED"

    android:gravity="center"

    android:orientation="horizontal">

    <TextView

        android:id="@+id/textViewSample"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:textSize="20sp"

        android:text="演示"/>

</RelativeLayout>

效果图

动画效果

 // 默认动画效果

 recyclerView.setItemAnimator(new DefaultItemAnimator());

notifyItemRemoved(position)

 /**

     * 删除指定的Item

     *

     * @param position

     */

    public void removeData(int position) {

        sampleData.remove(position);

        //  通知RecyclerView控件某个Item已经被删除

        notifyItemRemoved(position);

    }

notifyItemInserted(positionToAdd)

    /**

     * 在指定位置加入一个新的Item

     *

     * @param positionToAdd

     */

    public void addItem(int positionToAdd) {

        sampleData.add(positionToAdd, new SampleModel("新的列表项" + new Random().nextInt(10000)));

        //  通知RecyclerView控件插入了某个Item

        notifyItemInserted(positionToAdd);

    }

为RecyclerView加入item的点击事件

方法一：利用回调的方式实现(不太完好，仍可实现)

实现过程例如以下：

在adapter类中，定义接口，接口中定义两个方法分别相应click和longClick，定义完接口。加入接口和设置Adapter接口的方法：

  /**

     * 接口 ，提供两个方法

     */

    public interface OnRecyclerViewItemClickListener{

        // 单击事件

        void onItemClick(View view ,int position);

        // 长按触发的事件

        void onItemLongClick(View view ,int position);

    }

    // 定义OnRecyclerViewItemClickListener对象

    public OnRecyclerViewItemClickListener  mOnRecyclerViewItemClickListener ;

    // 暴漏给外部的set方法。持有OnRecyclerViewItemClickListener对象

    public void setOnRecyclerViewItemClickListener(OnRecyclerViewItemClickListener listener){

        this.mOnRecyclerViewItemClickListener = listener ;

    }

在onBindViewHolder方法中

 // 点击事件

        if(mOnRecyclerViewItemClickListener != null){

            // click

            holder.itemView.setOnClickListener(new View.OnClickListener() {

                @Override

                public void onClick(View v) {

                    mOnRecyclerViewItemClickListener.onItemClick(holder.itemView,position);

                }

            });

            // longClick

            holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {

                @Override

                public boolean onLongClick(View v) {

                    mOnRecyclerViewItemClickListener.onItemLongClick(holder.itemView,position);

                    return false;

                }

            });

        }

做完这些事情，我们就能够在Activity或其它地方为RecyclerView加入项目点击事件了，

// 设置监事件

        sampleRecyclerAdapter.setOnRecyclerViewItemClickListener(new SampleRecyclerAdapter.OnRecyclerViewItemClickListener() {

            @Override

            public void onItemClick(View view, int position) {

                Toast.makeText(RecyclerViewAct.this,"Click" + position ,Toast.LENGTH_SHORT).show();

            }

            @Override

            public void onItemLongClick(View view, int position) {

                Toast.makeText(RecyclerViewAct.this,"LongClick" + position ,Toast.LENGTH_SHORT).show();

            }

        });

完整代码例如以下：

RecyclerViewAct

package demo.turing.com.materialdesignwidget.recyclerView;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.support.v7.widget.DefaultItemAnimator;

import android.support.v7.widget.LinearLayoutManager;

import android.support.v7.widget.RecyclerView;

import android.view.View;

import android.widget.Toast;

import demo.turing.com.materialdesignwidget.R;

import demo.turing.com.materialdesignwidget.recyclerView.adapter.SampleRecyclerAdapter;

public class RecyclerViewAct extends AppCompatActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_recycler_view);

        // 获取RecyclerView对象

        RecyclerView recyclerView = (RecyclerView)findViewById(R.id.recycler_view);

        //  创建线性布局管理器（默认是垂直方向）

        LinearLayoutManager layoutManager = new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false);

        //  为RecyclerView指定布局管理对象

        recyclerView.setLayoutManager(layoutManager);

        //  创建列表项分隔线对象

        RecyclerView.ItemDecoration itemDecoration = new DividerItemDecoration(this,DividerItemDecoration.VERTICAL_LIST);

        //  为RecyclerView控件指定分隔线对象

        recyclerView.addItemDecoration(itemDecoration);

        // 默认动画效果

        recyclerView.setItemAnimator(new DefaultItemAnimator());

        SampleRecyclerAdapter sampleRecyclerAdapter = new SampleRecyclerAdapter();

        recyclerView.setAdapter(sampleRecyclerAdapter);

        // 设置监事件

        sampleRecyclerAdapter.setOnRecyclerViewItemClickListener(new SampleRecyclerAdapter.OnRecyclerViewItemClickListener() {

            @Override

            public void onItemClick(View view, int position) {

                Toast.makeText(RecyclerViewAct.this,"Click" + position ,Toast.LENGTH_SHORT).show();

            }

            @Override

            public void onItemLongClick(View view, int position) {

                Toast.makeText(RecyclerViewAct.this,"LongClick" + position ,Toast.LENGTH_SHORT).show();

            }

        });

    }

}

SampleRecyclerAdapter

package demo.turing.com.materialdesignwidget.recyclerView.adapter;

import android.support.v7.widget.RecyclerView;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.TextView;

import java.util.ArrayList;

import java.util.Random;

import demo.turing.com.materialdesignwidget.R;

import demo.turing.com.materialdesignwidget.recyclerView.SimulatorData;

import demo.turing.com.materialdesignwidget.recyclerView.model.SampleModel;

/**

 * MyApp

 *

 * @author Mr.Yang on 2016-03-30  21:03.

 * @version 1.0

 * @desc

 *

 *

 * RecyclerView  点击事件 请看http://jcodecraeer.com/a/anzhuokaifa/androidkaifa/2014/1118/2004.html

*/

public class SampleRecyclerAdapter extends RecyclerView.Adapter<SampleRecyclerAdapter.ViewHolder> {

    // 模拟数据

    private  ArrayList<SampleModel> sampleData = SimulatorData.getSampleModelData(20);

    /**

     * 接口 ，提供两个方法

     */

    public interface OnRecyclerViewItemClickListener{

        // 单击事件

        void onItemClick(View view ,int position);

        // 长按触发的事件

        void onItemLongClick(View view ,int position);

    }

    // 定义OnRecyclerViewItemClickListener对象

    public OnRecyclerViewItemClickListener  mOnRecyclerViewItemClickListener ;

    // 暴漏给外部的set方法。持有OnRecyclerViewItemClickListener对象

    public void setOnRecyclerViewItemClickListener(OnRecyclerViewItemClickListener listener){

        this.mOnRecyclerViewItemClickListener = listener ;

    }

    /**

     * 用于创建控件

     *

     * @param parent

     * @param viewType

     * @return

     */

    @Override

    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        // 获得列表项控件（LinearLayer对象）

        // list_basic_item.xml布局文件里仅仅包括一个<LinearLayer>标签，

        // 在该标签中包括了一个<TextView>标签, item是LinearLayout对象

        View item = LayoutInflater.from(parent.getContext()).inflate(

                R.layout.list_basic_item, parent, false);

        ViewHolder viewHolder = new ViewHolder(item);

        return viewHolder;

    }

    /**

     * 为控件设置数据

     *

     * @param holder

     * @param position

     */

    @Override

    public void onBindViewHolder(final ViewHolder holder, final int position) {

        //  获取当前item中显示的数据

        final SampleModel rowData = sampleData.get(position);

        //  设置要显示的数据

        holder.textViewSample.setText(rowData.getText());

        // 设置tag

        holder.itemView.setTag(rowData);

         // 点击事件

 if(mOnRecyclerViewItemClickListener != null){

            // click

        holder.itemView.setOnClickListener(new View.OnClickListener() {

                @Override

                public void onClick(View v) {

                    // 通过getLayoutPosition，防止position错位

                    int layoutPosition = holder.getLayoutPosition();

                    mOnRecyclerViewItemClickListener.onItemClick(holder.itemView,layoutPosition);

                }

            });

            // longClick

            holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {

                @Override

                public boolean onLongClick(View v) {

                    int layoutPosition = holder.getLayoutPosition();

                    mOnRecyclerViewItemClickListener.onItemLongClick(holder.itemView,layoutPosition);

                    return false;

                }

            });

        }

    }

    @Override

    public int getItemCount() {

        return sampleData.size();

    }

    /**

     * 删除指定的Item

     *

     * @param position

     */

    public void removeData(int position) {

        sampleData.remove(position);

        //  通知RecyclerView控件某个Item已经被删除

        notifyItemRemoved(position);

    }

    /**

     * 在指定位置加入一个新的Item

     *

     * @param positionToAdd

     */

    public void addItem(int positionToAdd) {

        sampleData.add(positionToAdd, new SampleModel("新的列表项" + new Random().nextInt(10000)));

        //  通知RecyclerView控件插入了某个Item

        notifyItemInserted(positionToAdd);

    }

    /**

     * 相应Item中的控件

     */

    public static class ViewHolder extends RecyclerView.ViewHolder {

        private final TextView textViewSample;

        public ViewHolder(View itemView) {

            super(itemView);

            textViewSample = (TextView) itemView

                    .findViewById(R.id.textViewSample);

        }

    }

}

方法二：使用观察者模式实现

原理：

为RecyclerView的每一个子item设置setOnClickListener。然后在onClick中再调用一次对外封装的接口。将这个事件传递给外面的调用者。而“为RecyclerView的每一个子item设置setOnClickListener”在Adapter中设置。事实上直接在onClick中也能全然处理item的点击事件，可是这样会破坏代码的逻辑。

步骤

在自己定义的adapter（记得implements View.OnClickListener，以下有个onClick方法）中定义例如以下接口,模拟ListView的OnItemClickListener：

 //define interface

 public static interface OnRecyclerViewItemClickListener {

        void onItemClick(View view , String data);

    }

声明一个这个接口的变量：

  private OnRecyclerViewItemClickListener mOnItemClickListener = null;

在onCreateViewHolder()中为每一个item加入点击事件：

 @Override

    public ViewHolder onCreateViewHolder(ViewGroup viewGroup,  int viewType) {

        View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item, viewGroup, false);

        ViewHolder vh = new ViewHolder(view);

        //将创建的View注冊点击事件

        view.setOnClickListener(this);

        return vh;

    }

将点击事件转移给外面的调用者：

 @Override

    public void onClick(View v) {

        if (mOnItemClickListener != null) {

            //注意这里使用getTag方法获取数据

            mOnItemClickListener.onItemClick(v,(String)v.getTag());

        }

    }

意上面调用接口的onItemClick()中的v.getTag()方法，这须要在onBindViewHolder()方法中设置和item相关的数据

@Override

    public void onBindViewHolder(ViewHolder viewHolder,  int position) {

        viewHolder.mTextView.setText(datas[position]);

        //将数据保存在itemView的Tag中，以便点击时进行获取

        viewHolder.itemView.setTag(datas[position]);

    }

最后暴露给外面的调用者，定义一个设置Listener的方法（）：

 public void setOnItemClickListener(OnRecyclerViewItemClickListener listener) {

        this.mOnItemClickListener = listener;

    }

以上全部步骤都发生在自己定义的adapter中，典型的观察者模式，有点绕的地方在于，这里涉及到两个观察者模式的使用，view的setOnClickListener本来就是观察者模式，我们将这个观察者模式的事件监听传递给了我们自己的观察者模式。

在Activity中使用

mRecyclerView = (RecyclerView)findViewById(R.id.my_recycler_view);

        //创建默认的线性LayoutManager

        mLayoutManager = new LinearLayoutManager(this);

        mRecyclerView.setLayoutManager(mLayoutManager);

        //假设能够确定每一个item的高度是固定的，设置这个选项能够提高性能

        mRecyclerView.setHasFixedSize(true);

        //创建并设置Adapter

        mAdapter = new MyAdapter(data);

        mRecyclerView.setAdapter(mAdapter);

        mAdapter.setOnItemClickListener(new OnRecyclerViewItemClickListener(){

            @Override

            public void onItemClick(View view , String data){

                Toast.makeText(MainActivity.this, data, 600).show();

            }

        });

~

RecyclerView加入Header

。。。。。。

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