RecyclerView 实现简单瀑布流的应用

效果
实现代码
需要的jar包

com.android.support:recyclerview-v7:28.0.0
com.android.support:cardview-v7:28.0.0

activitymain的xml代码

  <?xml version="1.0" encoding="utf-8"?>
    <android.support.v7.widget.CardView 
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:padding="4dp"
        app:cardBackgroundColor="#ffffffff"
        app:cardCornerRadius="15dp"
        tools:context=".MainActivity">
        
        <android.support.v7.widget.RecyclerView
            android:id="@+id/MyRec"
            android:layout_width="match_parent"
            android:layout_height="match_parent"></android.support.v7.widget.RecyclerView>
    </android.support.v7.widget.CardView>

bean包类

    public class MyData {
        /**
         * 名字
         */
        private String name;
        /**
         * 图片id
         */
        private int imageId;

        public MyData(String name, int imageId) {
            this.name = name;
            this.imageId = imageId;
        }

        public String getName() {
            return name;
        }

        public int getImageId() {
            return imageId;
        }
    }

适配器的xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#88ffffff">
<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center_horizontal"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/MyImg"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:scaleType="centerCrop" />

    <TextView
        android:id="@+id/MyName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>
</RelativeLayout>

适配器

import android.content.Context; 
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView; 
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView; 
import android.widget.TextView; 
import com.bwie.administrator.pubuliu.R; 
import com.bwie.administrator.pubuliu.bean.MyData; 
import java.util.ArrayList;

    public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
        private Context context;
        private ArrayList<MyData> datas;

        public MyAdapter(Context context, ArrayList<MyData> datas) {
            this.context = context;
            this.datas = datas;
        }

        @NonNull
        @Override
        public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
            //加载布局文件 
            View v = View.inflate(context, R.layout.item, null);
            ViewHolder holder = new ViewHolder(v);
            return holder;
        }

        @Override
        public void onBindViewHolder(@NonNull ViewHolder viewHolder, int i) {
            //对holder赋值 
            MyData myData = datas.get(i);
            viewHolder.MyImg.setImageResource(myData.getImageId());
            viewHolder.MyName.setText(myData.getName());
        }

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

        class ViewHolder extends RecyclerView.ViewHolder {
            private ImageView MyImg;
            private TextView MyName;

            public ViewHolder(@NonNull View itemView) {
                super(itemView);
                MyImg = itemView.findViewById(R.id.MyImg);
                MyName = itemView.findViewById(R.id.MyName);
            }
        }
    }

activity的代码

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;
import android.view.View;
import com.bwie.administrator.pubuliu.adapter.MyAdapter;
import com.bwie.administrator.pubuliu.bean.MyData;
import java.util.ArrayList;

    public class MainActivity extends AppCompatActivity {
        private RecyclerView recyclerView;
        private ArrayList<MyData> datas = new ArrayList<>();

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            recyclerView = findViewById(R.id.MyRec);
            //使用瀑布流 第一个参数为列数 第二个参数为排列方向 
            StaggeredGridLayoutManager manager = new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);
            recyclerView.setLayoutManager(manager);
            //初始化数据 initData(); 
            // 设置适配器
            MyAdapter adapter = new MyAdapter(this, datas);
            recyclerView.setAdapter(adapter);
        }

        private void initData() {
            MyData myData;
            //进行for循环添加数据 
            for (int i = 0; i < 20; i++) {
                myData = new MyData("美女", R.drawable.a);
                datas.add(myData);
                myData = new MyData("美女", R.drawable.b);
                datas.add(myData);
                myData = new MyData("美女", R.drawable.c);
                datas.add(myData);
                myData = new MyData("美女", R.drawable.d);
                datas.add(myData);
            }
        }
    }