recyclerView的用法

Posted 2021-02-05 837634902why

1》用recyclerView实现上次ListView实现的效果

导入包

dependencies {
    compile fileTree(dir: ‘libs‘, include: [‘*.jar‘])
    androidTestCompile(‘com.android.support.test.espresso:espresso-core:2.2.2‘, {
        exclude group: ‘com.android.support‘, module: ‘support-annotations‘
    })
    compile ‘com.android.support:appcompat-v7:26.+‘
    compile ‘com.android.support:recyclerview-v7:26.0.0-alpha1‘//导入相关的support包
    testCompile ‘junit:junit:4.12‘
}

导入recyclerView布局

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >
    //引入recyclerview布局
    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        />


</LinearLayout>

创造适配器

package com.example.recyelerview;

import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.List;

/**
 * Created by lenovo on 2019/1/26.
 */

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){//view为子项最外布局，需要获取fruitName和fruitImage
            super(view);
            fruitImage=(ImageView)view.findViewById(R.id.fruit_image);
            fruitName=(TextView)view.findViewById(R.id.fruit_name);
        }
    }
    public FruitAdapter(List<Fruit> fruitList){
        mFruitList=fruitList;
    }

    @Override
    //加载布局
    public 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;

    }

    @Override
    //对进入屏幕的子项赋值
    public void onBindViewHolder(ViewHolder holder, int position) {
        Fruit fruit=mFruitList.get(position);
        holder.fruitImage.setImageResource(fruit.getImageId());
        holder.fruitName.setText(fruit.getName());
    }

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

main.java

package com.example.recyelerview;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private List<Fruit> fruitList=new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initFruits();
        RecyclerView recyclerView=(RecyclerView)findViewById(R.id.recycler_view);
        LinearLayoutManager linearLayoutManager=new LinearLayoutManager(this);//线性布局
       recyclerView.setLayoutManager(linearLayoutManager);
        FruitAdapter adapter=new FruitAdapter(fruitList);
        recyclerView.setAdapter(adapter);
    }
    private void initFruits(){
        for(int i=0;i<2;i++) {
            Fruit f1 = new Fruit("梨", R.drawable.p1);
            fruitList.add(f1);
            Fruit f2 = new Fruit("苹果", R.drawable.p2);
            fruitList.add(f2);
            Fruit f3 = new Fruit("沙果", R.drawable.p3);
            fruitList.add(f3);
            Fruit f4 = new Fruit("海棠", R.drawable.p4);
            fruitList.add(f4);
            Fruit f5 = new Fruit("野樱莓", R.drawable.p5);
            fruitList.add(f5);
            Fruit f6 = new Fruit("山楂", R.drawable.p6);
            fruitList.add(f6);
            Fruit f7 = new Fruit("杏", R.drawable.p7);
            fruitList.add(f7);
            Fruit f8 = new Fruit("樱桃", R.drawable.p8);
            fruitList.add(f8);
            Fruit f9 = new Fruit("李子", R.drawable.p9);
            fruitList.add(f9);
            Fruit f10 = new Fruit("草莓", R.drawable.p10);
            fruitList.add(f10);

        }




    }
}

Fruit类和fruit_item.xml与上一次的相同

 

2》实现横向滚动

修改fruit_item.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="wrap_content"
    android:layout_height="150dp">
    <ImageView
        android:id="@+id/fruit_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"/>
    <TextView
        android:id="@+id/fruit_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="10dp"/>//水平居中
</LinearLayout>

修改main.java

 LinearLayoutManager linearLayoutManager=new LinearLayoutManager(this);//线性布局
 linearLayoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);//默认是竖型排列，现在换为横向
 recyclerView.setLayoutManager(linearLayoutManager);

3》瀑布排序

修改fruit_item.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="5dp">
    <ImageView
        android:id="@+id/fruit_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"/>
    <TextView
        android:id="@+id/fruit_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="left"
        android:layout_marginTop="10dp"/>//水平居中
</LinearLayout>

修改mian.java

package com.example.recyelerview;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

public class MainActivity extends AppCompatActivity {
    private List<Fruit> fruitList=new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initFruits();
        RecyclerView recyclerView=(RecyclerView)findViewById(R.id.recycler_view);
       // LinearLayoutManager linearLayoutManager=new LinearLayoutManager(this);//线性布局
        //linearLayoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
        StaggeredGridLayoutManager layoutManager=new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL);
       recyclerView.setLayoutManager(layoutManager);
        FruitAdapter adapter=new FruitAdapter(fruitList);
        recyclerView.setAdapter(adapter);
    }
    private void initFruits(){
        for(int i=0;i<2;i++) {
            Fruit f1 = new Fruit(getTRandomName("梨"), R.drawable.p1);
            fruitList.add(f1);
            Fruit f2 = new Fruit(getTRandomName("苹果"), R.drawable.p2);
            fruitList.add(f2);
            Fruit f3 = new Fruit(getTRandomName("沙果"), R.drawable.p3);
            fruitList.add(f3);
            Fruit f4 = new Fruit(getTRandomName("海棠"), R.drawable.p4);
            fruitList.add(f4);
            Fruit f5 = new Fruit(getTRandomName("海棠"), R.drawable.p5);
            fruitList.add(f5);
            Fruit f6 = new Fruit(getTRandomName("山楂"), R.drawable.p6);
            fruitList.add(f6);
            Fruit f7 = new Fruit(getTRandomName("杏"), R.drawable.p7);
            fruitList.add(f7);
            Fruit f8 = new Fruit(getTRandomName("樱桃"), R.drawable.p8);
            fruitList.add(f8);
            Fruit f9 = new Fruit(getTRandomName("李子"), R.drawable.p9);
            fruitList.add(f9);
            Fruit f10 = new Fruit(getTRandomName("草莓"), R.drawable.p10);
            fruitList.add(f10);

        }
    }
    private String getTRandomName(String name){
        Random random=new Random();
        int length=random.nextInt(20)+1;
        StringBuilder builder=new StringBuilder();
        for(int i=0;i<length;i++){
            builder.append(name);
        }
        return builder.toString();
    }
}

 

GridLayoutManager网格布局

recyclerview实现GridView效果

    GridLayoutManager layoutManage = new GridLayoutManager(getContext(), 2);
    recycerView.setLayoutManager(layoutManage);

 

 https://www.jianshu.com/p/675883c26ef2

添加点击事件修改FruitAdapter

package com.example.recyelerview;

import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import java.util.List;

/**
 * Created by lenovo on 2019/1/26.
 */

public class FruitAdapter extends RecyclerView.Adapter<FruitAdapter.ViewHolder> {
    private List<Fruit> mFruitList;
    static class ViewHolder extends RecyclerView.ViewHolder{
        ImageView fruitImage;
        TextView fruitName;
//添加一个view来保存布局实例
        View fruitView;
        public ViewHolder(View view){//view为子项最外布局，需要获取fruitName和fruitImage
            super(view);
//赋值
            fruitView=view;
            fruitImage=(ImageView)view.findViewById(R.id.fruit_image);
            fruitName=(TextView)view.findViewById(R.id.fruit_name);
        }
    }
    public FruitAdapter(List<Fruit> fruitList){
        mFruitList=fruitList;
    }

    @Override
    //加载布局
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view= LayoutInflater.from(parent.getContext()).inflate(R.layout.fruit_item,parent,false);
//
        final ViewHolder holder=new ViewHolder(view);
        holder.fruitView.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View view) {
                int position=holder.getAdapterPosition();
                Fruit fruit=mFruitList.get(position);
                Toast.makeText(view.getContext(),"you chick view +"+fruit.getName(),Toast.LENGTH_SHORT).show();;
            }
        });
        holder.fruitImage.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View view) {
                int position=holder.getAdapterPosition();
                Fruit fruit=mFruitList.get(position);
                Toast.makeText(view.getContext(),"you chick image +"+fruit.getName(),Toast.LENGTH_SHORT).show();;
            }
        });
        return holder;

    }

    @Override
    //对进入屏幕的子项赋值
    public void onBindViewHolder(ViewHolder holder, int position) {
        Fruit fruit=mFruitList.get(position);
        holder.fruitImage.setImageResource(fruit.getImageId());
        holder.fruitName.setText(fruit.getName());
    }

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

 

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