RecyclerView是用来替代ListView、GridView的一个牛掰的控件。用起来更灵活，还能实现线性布局（横向、纵向）、网格布局、瀑布流等美观的UI。
在使用RecyclerView时候，必须指定一个适配器Adapter和一个布局管理器LayoutManager。适配器继承RecyclerView.Adapter类
首先在build.gradle中加入依赖库
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:26.1.0'
implementation 'com.android.support:recyclerview-v7:26.1.0'//添加RecycleView的依赖库
implementation 'com.android.support.constraint:constraint-layout:1.1.0'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
} |
布局文件activity_main.xml中添加recyclerview
<?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">
<android.support.v7.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</LinearLayout> |
fruit_item.xml中
<?xml version="1.0" encoding="utf-8"?>
<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" />
</LinearLayout> |
Fruit类
package com.fengbang.recyclerviewtest;
public class Fruit {
private String name;
private int imageId;
public Fruit(String name, int imageId) {
this.name = name;
this.imageId = imageId;
}
public String getName() {
return name;
}
public int getImageId() {
return imageId;
}
} |
FruitAdapter类
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){
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
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);
//自定义事件
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(),fruit.getName(),Toast.LENGTH_SHORT).show();
}
});
return holder;
}
@Override
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();
}
} |
MainActivity使用RecycleView
public class MainActivity extends AppCompatActivity {
private List<Fruit> fruitList = new ArrayList<Fruit>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initFruits();
RecyclerView recyclerView = findViewById(R.id.recycler_view);
// LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
// linearLayoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
StaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL);
recyclerView.setLayoutManager(staggeredGridLayoutManager);
FruitAdapter fruitAdapter = new FruitAdapter(fruitList);
recyclerView.setAdapter(fruitAdapter);
}
private void initFruits() {
for (int i = 0; i < 2; i++) {
Fruit apple = new Fruit(getRandomLengthName("Apple"), R.drawable.apple_pic);
fruitList.add(apple);
Fruit banana = new Fruit(getRandomLengthName("Banana"), R.drawable.banana_pic);
fruitList.add(banana);
Fruit orange = new Fruit(getRandomLengthName("Orange"), R.drawable.orange_pic);
fruitList.add(orange);
Fruit watermelon = new Fruit(getRandomLengthName("Watermelon"), R.drawable.watermelon_pic);
fruitList.add(watermelon);
Fruit pear = new Fruit(getRandomLengthName("Pear"), R.drawable.pear_pic);
fruitList.add(pear);
Fruit grape = new Fruit(getRandomLengthName("Grape"), R.drawable.grape_pic);
fruitList.add(grape);
Fruit pineapple = new Fruit(getRandomLengthName("Pineapple"), R.drawable.pineapple_pic);
fruitList.add(pineapple);
Fruit strawberry = new Fruit(getRandomLengthName("Strawberry"), R.drawable.strawberry_pic);
fruitList.add(strawberry);
Fruit cherry = new Fruit(getRandomLengthName("Cherry"), R.drawable.cherry_pic);
fruitList.add(cherry);
Fruit mango = new Fruit(getRandomLengthName("Mango"), R.drawable.mango_pic);
fruitList.add(mango);
}
}
//为了瀑布流随机生成不同长度的字符串
private String getRandomLengthName(String name){
Random random = new Random();
int length=random.nextInt(20)+1;
StringBuilder stringBuilder = new StringBuilder();
for (int i=0;i<length;i++){
stringBuilder.append(name);
}
return stringBuilder.toString();
}
} |
最终结果
