Android : 瀑布流

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

package com.bwie.administrator.pubuliu.bean;

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

package com.bwie.administrator.pubuliu.adapter;

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

package com.bwie.administrator.pubuliu;

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);
        }
    }
}

以上