RecyclerView控件的使用

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Recyclerview已经推出很长时间了，近段时间工作不是很忙，就把以前所有项目的ListView都更新到 Recyclerview了，功能蛮强大的，具体的就不多说了，在这里就给大家分享下实际运用中的方法吧。

在build.gradle文件中添加依赖包（android studio开发工具）

 compile 'com.android.support:recyclerview-v7:24.1.1'

main_layout布局文件：

<?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"    tools:context="com.eric.recyclerviewdemo.MainActivity">    <android.support.v7.widget.RecyclerView        android:id="@+id/recycler_view"        android:layout_width="match_parent"        android:layout_height="match_parent"/></RelativeLayout>

item_layout布局文件：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="match_parent"    android:layout_height="56dp">    <TextView        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:id="@+id/item_text"        android:padding="10dp"        android:textSize="18sp"/></LinearLayout>

MainActivity代码：

public class MainActivity extends AppCompatActivity {    private RecyclerView recyclerView;    private DemoAdapter adapter;    private List<String> mDatas;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        //创建对象        recyclerView = (RecyclerView) findViewById(R.id.recycler_view);        //准备数据        mDatas = new ArrayList<>();        for (int i = 0; i < 50; i++) {            mDatas.add("RecyclerView item"+i);        }        LinearLayoutManager layoutManager = new LinearLayoutManager(this);        //设置布局管理器        recyclerView.setLayoutManager(layoutManager);        //设置垂直布局方式（系统默认也是垂直的）        layoutManager.setOrientation(OrientationHelper.VERTICAL);        //设置适配器adapter        adapter = new DemoAdapter(this,mDatas);        //设置分隔线        recyclerView.addItemDecoration( new DividerItemDecoration(this,DividerItemDecoration.VERTICAL_LIST));        recyclerView.setAdapter(adapter);    }}

DemoAdapter代码：

public class DemoAdapter extends RecyclerView.Adapter {    private Context context;    private List<String> mData;    public DemoAdapter(Context context, List<String> datas) {        this.context = context;        this.mData = datas;    }    @Override    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        View view = LayoutInflater.from(context).inflate(R.layout.item_layout,parent,false);        return new MyViewHolder(view);    }    private class MyViewHolder extends RecyclerView.ViewHolder {        TextView tv;        public MyViewHolder(View itemView) {            super(itemView);            tv = (TextView) itemView.findViewById(R.id.item_text);        }    }    @Override    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {        MyViewHolder myHolder = (MyViewHolder) holder;        myHolder.tv.setText(mData.get(position));    }    @Override    public int getItemCount() {        return mData.size();    }}

DividerItemDecoration代码：

public class DividerItemDecoration extends RecyclerView.ItemDecoration{    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){        final TypedArray a = context.obtainStyledAttributes(ATTRS);        mDivider = a.getDrawable(0);        a.recycle();        setOrientation(orientation);    }    private 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);        }    }    //垂直分割线    private 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);            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);        }    }    //水平分割线    private 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);        }    }}

运行效果：
这里写图片描述

给RecyclerView的Item添加点击事件，在DemoAdapter修改代码如下：

public class DemoAdapter extends RecyclerView.Adapter {    private Context context;    private List<String> mData;    private OnItemCLickListener myItemCLickListener;    //创建item点击事件的接口    public interface OnItemCLickListener{        void onClick(View view,int position);    }    //创建外部调用的回调方法    public void setItemCLickListener(OnItemCLickListener itemCLickListener) {        this.myItemCLickListener = itemCLickListener;    }    public DemoAdapter(Context context, List<String> datas) {        this.context = context;        this.mData = datas;    }    @Override    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        View view = LayoutInflater.from(context).inflate(R.layout.item_layout,parent,false);        return new MyViewHolder(view);    }    class MyViewHolder extends RecyclerView.ViewHolder {        TextView tv;        public MyViewHolder(View itemView) {            super(itemView);            tv = (TextView) itemView.findViewById(R.id.item_text);            itemView.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View view) {                    myItemCLickListener.onClick(view,getPosition());                }            });        }    }    @Override    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {        MyViewHolder myHolder = (MyViewHolder) holder;        myHolder.tv.setText(mData.get(position));    }    @Override    public int getItemCount() {        return mData.size();    }}

MainActivity实现点击事件方法：

 //实现点击事件        adapter.setItemCLickListener(new DemoAdapter.OnItemCLickListener() {            @Override            public void onClick(View view, int position) {                Toast.makeText(MainActivity.this, "你点击了"+mDatas.get(position), Toast.LENGTH_SHORT).show();            }        });

实现 item 点击选中变色的效果，在DemoAdapter增加以下代码：

public class DemoAdapter extends RecyclerView.Adapter {    private Context context;    private List<String> mData;    private int selectPosition = -1； //选中的位置    private OnItemCLickListener myItemCLickListener;    //创建item点击事件的接口    public interface OnItemCLickListener{        void onClick(View view,int position);    }    //创建外部调用的回调方法    public void setItemCLickListener(OnItemCLickListener itemCLickListener) {        this.myItemCLickListener = itemCLickListener;    }    //定义一个setPosition的方法供Activity调用获取position的值    public void setSelectPosition(int selectPosition) {        this.selectPosition = selectPosition;    }    public DemoAdapter(Context context, List<String> datas) {        this.context = context;        this.mData = datas;    }    @Override    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        View view = LayoutInflater.from(context).inflate(R.layout.item_layout,parent,false);        return new MyViewHolder(view);    }    class MyViewHolder extends RecyclerView.ViewHolder {        TextView tv;        public MyViewHolder(View itemView) {            super(itemView);            tv = (TextView) itemView.findViewById(R.id.item_text);            itemView.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View view) {                    myItemCLickListener.onClick(view,getPosition());                }            });        }    }    @Override    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {        MyViewHolder myHolder = (MyViewHolder) holder;        myHolder.tv.setText(mData.get(position));        //判断当前点击的position并改变颜色        if (selectPosition == position){            vh.tv.setBackgroundColor(Color.RED);        }else {            vh.tv.setBackgroundColor(Color.TRANSPARENT);        }    }    @Override    public int getItemCount() {        return mData.size();    }}

MainActivity增加实现方法：

//实现点击事件        adapter.setItemCLickListener(new DemoAdapter.OnItemCLickListener() {            @Override            public void onClick(View view, int position) {                Toast.makeText(MainActivity.this, "你点击了"+mDatas.get(position), Toast.LENGTH_SHORT).show();                adapter.setSelectPosition(position);                adapter.notifyDataSetChanged();            }        });

运行效果就不贴出来了，小伙伴们自己去试试吧！！！喜欢的请支持我一下！(￣▽￣*)

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