Android RecyclerView 瀑布流

 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@android:color/holo_blue_light">

    <ImageView
        android:id="@+id/iv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:padding="10dp"
        android:src="@mipmap/ic_launcher"
        android:scaleType="fitXY"
        android:adjustViewBounds="true"/>

</LinearLayout>

导入RecyclerView包

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerview"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </android.support.v7.widget.RecyclerView>
</RelativeLayout>

public class MainActivity extends AppCompatActivity {

    RecyclerView mRecycleView;
    List<Image> mList = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mRecycleView = (RecyclerView) findViewById(R.id.recyclerview);
        //初始化数据
        initData();
        //设置适配器
        mRecycleView.setAdapter(new MyAdapter());
        //设置布局管理器
        //mRecycleView.setLayoutManager(new LinearLayoutManager(this));//与ListView类似
        mRecycleView.setLayoutManager(new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL));
        //设置item分割线

        //设置item动画
    }


    private void initData() {
        for (int i = 1; i <= 20; i++) {
            try {

                mList.add(new Image(R.mipmap.class.getField("img0"+i).getInt(null)));

            } catch (IllegalAccessException e) {
                e.printStackTrace();
            } catch (NoSuchFieldException e) {
                e.printStackTrace();
            }
        }


    }


    //布局的内容组件
    class MyViewHolder extends RecyclerView.ViewHolder{

        ImageView iv;

        public MyViewHolder(View itemView) {
            super(itemView);
            iv = (ImageView) itemView.findViewById(R.id.iv);
        }
    }

    //适配器，继承RecyclerView.Adapter,泛型，里面必须是Recycler.ViewHolder的子类
    class MyAdapter extends RecyclerView.Adapter<MyViewHolder>{

        /**
         * 一个页面没有加载完毕，会持续调用该方法。
         * @param parent
         * @param viewType
         * @return
         */
        @Override
        public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            //创建ViewHolder
            //导入布局
            View layout = View.inflate(getBaseContext(),R.layout.item_layout,null);
            MyViewHolder viewHolder = new MyViewHolder(layout);
            return viewHolder;
        }

        @Override
        public void onBindViewHolder(MyViewHolder holder, int position) {
            //为每一个布局设置属性。
            //holder  组件
            //当前第几项， mList.get(position)拿到数据，给holder设置

            holder.iv.setImageResource(mList.get(position).imgId);
        }

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

    class Image{
        int imgId;
        public Image(int imgId){
            this.imgId = imgId;
        }
    }
}