RecyclerView的基础使用

最新推荐文章于 2024-09-15 08:29:20 发布

原创最新推荐文章于 2024-09-15 08:29:20 发布 · 255 阅读

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本文介绍如何使用Android的RecyclerView组件创建一个带有自定义布局的列表应用。通过示例代码展示了RecyclerView的配置方法，包括依赖项添加、布局文件定义、适配器编写及不同显示模式的设置。

先引入RecyclerView依赖包，V7下的，兼容到API17

compile 'com.android.support:mediarouter-v7:25.0.0'
compile 'com.android.support:appcompat-v7:25.0.0'
compile 'com.android.support:recyclerview-v7:25.0.0'

Activity的布局

<android.support.v7.widget.RecyclerView
    android:id="@+id/id_recyclerview"
    android:divider="#ffff0000"
    android:dividerHeight="10dp"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

item的布局

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:background="#44ff0000"
    android:layout_height="wrap_content" >

    <TextView
        android:id="@+id/id_num"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:gravity="center"
        android:text="1" />
</FrameLayout>

MainActivity中

public class MainActivity extends AppCompatActivity {
    private RecyclerView mRecyclerView;
    private List<String> mDatas;
    private HomeAdapter mAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initData();
        mRecyclerView = (RecyclerView) findViewById(R.id.id_recyclerview);
      //mRecyclerView.setLayoutManager(new LinearLayoutManager(this));//listview展示
      //mRecyclerView.setLayoutManager(new GridLayoutManager(this,4));//gridview展示

        mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(2,StaggeredGridLayoutManager.VERTICAL));
        //设置item之间的间隔
        SpacesItemDecoration decoration=new SpacesItemDecoration(30);
        mRecyclerView.addItemDecoration(decoration);
         //添加适配器
        mRecyclerView.setAdapter(mAdapter = new HomeAdapter());
        //添加分割线
        mRecyclerView.addItemDecoration(new DividerItemDecoration(
                MainActivity.this, DividerItemDecoration.VERTICAL

        ));
        //添加分割线
        mRecyclerView.addItemDecoration(new DividerItemDecoration(
                MainActivity.this, DividerItemDecoration.HORIZONTAL

        ));
    }
//添加数据
 protected void initData()
    {
        mDatas = new ArrayList<String>();
        for (int i = 'A'; i < 'z'; i++)
        {
            mDatas.add("" + (char) i);
        }
    }
//添加适配器
 class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.MyViewHolder> {

        @Override
        public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            MyViewHolder holder = new MyViewHolder(LayoutInflater.from(
                    MainActivity.this).inflate(R.layout.item_home, parent,
                    false));
            return holder;
        }

        @Override
        public void onBindViewHolder(MyViewHolder holder, int position) {
            holder.tv.setText(mDatas.get(position));
        }

        @Override
        public int getItemCount() {
            return mDatas.size();
        }

        class MyViewHolder extends RecyclerView.ViewHolder {

            TextView tv;

            public MyViewHolder(View view) {
                super(view);
                tv = (TextView) view.findViewById(R.id.id_num);
            }
        }
    }
    public class SpacesItemDecoration extends RecyclerView.ItemDecoration {

        private int space;

        public SpacesItemDecoration(int space) {
            this.space=space;
        }

        @Override
        public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
            outRect.left=space;
            outRect.right=space;
            outRect.bottom=space;
            if(parent.getChildAdapterPosition(view)==0){
                outRect.top=space;
            }
        }
    }
}