recyclerView的用法

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);

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();    }}

2