安卓控件RecyclerVieW

导入依赖

  file→Project Structure…→Dependencies→ app→ + → Library Dependency。

  输入androidx.recyclerview，然后点击Search。

简单使用

  修改activity_main.xml中的代码。在布局中加入RecyclerView控件也是非常简单的，先为RecyclerView指定一个id，然后将宽度和高度都设置为match_parent，这样RecyclerView就占满了整个布局的空间。需要注意的是，由于RecyclerView并不是内置在系统SDK当中的，所以需要把完整的包路径写出来。

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"><androidx.recyclerview.widget.RecyclerViewandroid:id="@+id/recyclerView"android:layout_width="match_parent"android:layout_height="match_parent" />
</LinearLayout>

  自定义布局fruit_item.xml。

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="60dp"><ImageViewandroid:id="@+id/fruitImage"android:layout_width="40dp"android:layout_height="40dp"android:layout_gravity="center_vertical"android:layout_marginLeft="10dp"/><TextViewandroid:id="@+id/fruitName"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_gravity="center_vertical"android:layout_marginLeft="10dp" />
</LinearLayout>

  编写Fruit类。

public class Fruit {private String name;private int imageId;public Fruit(String name,int imageId){this.name = name;this.imageId = imageId;}public String getName(){return name;}public int getImageId(){return imageId;}
}

  创建一个继承自ArrayAdapter的自定义适配器FruitAdapter。

public class FruitAdapter extends RecyclerView.Adapter<FruitAdapter.ViewHolder> {private List<Fruit> mFruitList;static class ViewHolder extends RecyclerView.ViewHolder{ImageView fruitImage;TextView fruitName;public ViewHolder(View view){super(view);fruitImage = (ImageView)  view.findViewById(R.id.fruitImage);fruitName = (TextView) view.findViewById(R.id.fruitName);}}public FruitAdapter(List<Fruit> fruitList){mFruitList = fruitList;}@Overridepublic ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.fruit_item, parent, false);ViewHolder holder = new ViewHolder(view);return holder;}@Overridepublic void onBindViewHolder(ViewHolder holder, int position){Fruit fruit = mFruitList.get(position);holder.fruitImage.setImageResource(fruit.getImageId());holder.fruitName.setText(fruit.getName());}@Overridepublic int getItemCount(){return mFruitList.size();}
}

  最后修改MainActivity中的代码。

public class MainActivity extends AppCompatActivity {private  List<Fruit> fruitList = new ArrayList<>();@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);initFruits(); // 初始化数据RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerView);LinearLayoutManager layoutManager = new LinearLayoutManager(this);recyclerView.setLayoutManager(layoutManager);FruitAdapter adapter = new FruitAdapter(fruitList);recyclerView.setAdapter(adapter);}private void initFruits(){for(int i = 0; i < 2; i++){Fruit apple = new Fruit("Apple", R.mipmap.ic_launcher);fruitList.add(apple);Fruit banana = new Fruit("banana", R.mipmap.ic_launcher);fruitList.add(banana);Fruit orange = new Fruit("orange", R.mipmap.ic_launcher);fruitList.add(orange);Fruit waternelon = new Fruit("waternelon", R.mipmap.ic_launcher);fruitList.add(waternelon);Fruit pear = new Fruit("pear", R.mipmap.ic_launcher);fruitList.add(pear);Fruit grape = new Fruit("grape", R.mipmap.ic_launcher);fruitList.add(grape);Fruit pineapple = new Fruit("pineapple", R.mipmap.ic_launcher);fruitList.add(pineapple);}}
}

实现横向滚动

  修改自定义布局fruit_item.xml。

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"<!--修改部分-->android:orientation="vertical"android:layout_width="80dp"android:layout_height="match_parent"><!--修改部分--><ImageViewandroid:id="@+id/fruitImage"android:layout_width="40dp"android:layout_height="40dp"<!--修改部分-->android:layout_gravity="center_horizontal"android:layout_marginTop="10dp"/><!--修改部分--><TextViewandroid:id="@+id/fruitName"android:layout_width="wrap_content"android:layout_height="wrap_content"<!--修改部分-->android:layout_gravity="center_horizontal"android:layout_marginTop="10dp" /><!--修改部分-->
</LinearLayout>

  修改MainActivity中的代码。传入LinearLayoutManager.HORIZONTAL表示让布局横行排列

protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);initFruits(); // 初始化数据RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerView);LinearLayoutManager layoutManager = new LinearLayoutManager(this);// 新加代码layoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);// --------recyclerView.setLayoutManager(layoutManager);FruitAdapter adapter = new FruitAdapter(fruitList);recyclerView.setAdapter(adapter);}

瀑布式

  修改自定义布局fruit_item.xml。

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="vertical"android:layout_width="match_parent"android:layout_height="match_parent"android:layout_margin="5dp"><ImageViewandroid:id="@+id/fruitImage"android:layout_width="match_parent"android:layout_height="match_parent"android:layout_gravity="center_horizontal" /><TextViewandroid:id="@+id/fruitName"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_gravity="left"android:layout_marginTop="10dp" />
</LinearLayout>

  修改自定义布局fruit_item.xml。

protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);initFruits(); // 初始化数据RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerView);/*LinearLayoutManager layoutManager = new LinearLayoutManager(this);layoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);*/StaggeredGridLayoutManager layoutManager = new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL);recyclerView.setLayoutManager(layoutManager);FruitAdapter adapter = new FruitAdapter(fruitList);recyclerView.setAdapter(adapter);}