RecyclerView 的简单使用

移动开发 作者: 2024-08-22 00:10:01
自从 Android 5.0 之后,google 推出了一个 RecyclerView 控件,他是 support-v7 包中的新组件,是一个强大的滑动组件,与经典的 ListView 相比,同样拥有

引入 RecyclerVIew

compile 'com.android.support:recyclerview-v7:25.1.0'

创建布局文件

主布局文件
/*activity_main.xml*/
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    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.manu.mrecyclerview.MainActivity">
    <android.support.v7.widget.RecyclerView
        android:id="@+id/rv"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    </android.support.v7.widget.RecyclerView>
</LinearLayout>
Item布局文件
/*item.xml*/
<?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="match_parent"
    android:padding="5dp">
    <TextView
        android:id="@+id/tv_recycle"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:text="data"
        android:background="#cac3c3"
        android:padding="10dp"
        android:textSize="20sp"/>
</LinearLayout>

创建Adapter

onCreateViewHolder()
onBindViewHolder()
getItemCount()
Adapter代码
/**
 * Created by jzman on 2017/5/13 0013.
 */
public class RvAdapter extends RecyclerView.Adapter<RvAdapter.DataViewHolder>{
    private Context mContext;
    private ArrayList<String> mList;

    public RvAdapter() {}

    public RvAdapter(Context mContext,ArrayList<String> mList) {
        this.mContext = mContext;
        this.mList = mList;
    }

    //用于创建ViewHolder
    @Override
    public DataViewHolder onCreateViewHolder(ViewGroup parent,int viewType) {
        View view = LayoutInflater.from(mContext).inflate(R.layout.item,null);
        //使用代码设置宽高(xml布局设置无效时)
        view.setLayoutParams(new ViewGroup.LayoutParams(
                ViewGroup.LayoutParams.MATCH_PARENT,ViewGroup.LayoutParams.WRAP_CONTENT));
        DataViewHolder holder = new DataViewHolder(view);
        return holder;
    }
    //绑定数据
    @Override
    public void onBindViewHolder(DataViewHolder holder,int position) {
        holder.tv_data.setText(mList.get(position));
    }
    //数据总数
    @Override
    public int getItemCount() {
        return mList.size();
    }

    //创建ViewHolder
    public static class DataViewHolder extends RecyclerView.ViewHolder{
        TextView tv_data;
        public DataViewHolder(View itemView) {
            super(itemView);
            tv_data = (TextView) itemView.findViewById(R.id.tv_recycle);
        }
    }
/**
 * Created by jzman on 2017/5/13 0013.
 * RecycleView的Adapter
 */
public class RvAdapter extends RecyclerView.Adapter<RvAdapter.DataViewHolder>{
    private Context mContext;
    private RecyclerView recyclerView;
    private ArrayList<String> mList;
    private ArrayList<Integer> mHeight;

    public RvAdapter() {}

    public RvAdapter(Context mContext,ArrayList<String> mList) {
        this.mContext = mContext;
        this.mList = mList;
    }

    /**
     * 初始化每个Item的高度(瀑布流效果)
     * @return
     */
    public ArrayList<Integer> initHeight(){
        mHeight = new ArrayList<>();
        for (int i=0;i<mList.size();i++){
            mHeight.add((int) (Math.random()*300)+200);
        }
        return mHeight;
    }

    /**
     * 用于创建ViewHolder
     * @param parent
     * @param viewType
     * @return
     */
    @Override
    public DataViewHolder onCreateViewHolder(ViewGroup parent,ViewGroup.LayoutParams.WRAP_CONTENT));
        DataViewHolder holder = new DataViewHolder(view);
        return holder;
    }

    /**
     * 绑定数据
     * @param holder
     * @param position
     */
    @Override
    public void onBindViewHolder(DataViewHolder holder,int position) {
        //设置每个Item的高度
        ViewGroup.LayoutParams h = holder.tv_data.getLayoutParams();
        h.height = mHeight.get(position);
        holder.tv_data.setText(mList.get(position));
    }

    /**
     * 选项总数
     * @return
     */
    @Override
    public int getItemCount() {
        return mList.size();
    }

    /**
     * 创建ViewHolder
     */
    public static class DataViewHolder extends RecyclerView.ViewHolder{
        TextView tv_data;
        public DataViewHolder(View itemView) {
            super(itemView);
            tv_data = (TextView) itemView.findViewById(R.id.tv_recycle);
        }
    }
    /**
     *   将RecycleView附加到Adapter上
     */
    @Override
    public void onAttachedToRecyclerView(RecyclerView recyclerView) {
        super.onAttachedToRecyclerView(recyclerView);
        this.recyclerView= recyclerView;
        //初始化每个Item的高度
        initHeight();
    }
    /**
     *   将RecycleView从Adapter解除
     */
    @Override
    public void onDetachedFromRecyclerView(RecyclerView recyclerView) {
        super.onDetachedFromRecyclerView(recyclerView);
        this.recyclerView = null;
    }
}

MainActivity

/**
 * Created by jzman on 2017/5/13 0013.
 */
public class MainActivity extends AppCompatActivity {
    private RecyclerView rv;
    RvAdapter adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        rv = (RecyclerView) findViewById(R.id.rv);
        //设置布局管理器
        rv.setLayoutManager(new LinearLayoutManager(this));//线性
//        rv.setLayoutManager(new GridLayoutManager(this,4));//线性
//        rv.setLayoutManager(new StaggeredGridLayoutManager(4,StaggeredGridLayoutManager.VERTICAL));//线性
        adapter = new RvAdapter(this,initData());
        rv.setAdapter(adapter);
    }
    public static ArrayList<String> initData(){
        ArrayList<String> arrayList = new ArrayList<>();
        for (int i=0;i<50;i++){
            arrayList.add("第"+i+"条数据");
        }
        return arrayList;
    }
}

显示效果

LinearLayoutManager GridLayoutManager StaggeredGridLayoutManager
image image image
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