androidx RecyclerView的使用
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2022-03-13 16:45:11
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添加RecyclerView扩展
在app/build.gradle里面添加
implementation 'androidx.recyclerview:recyclerview:1.0.0'
修改activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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="match_parent"
tools:context=".MainActivity">
<androidx.recyclerview.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/rv_fruit"></androidx.recyclerview.widget.RecyclerView>
</androidx.constraintlayout.widget.ConstraintLayout>
新建一个布局文件
新建一个布局文件fruit_item.xml用来动态载入
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/iv_fruit">
</ImageView>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/tv_fruit">
</TextView>
</LinearLayout>
fruit数据类
package cn.edu.zufe.appsecond.bean;
public class Fruit {
public Fruit(String fruitName, int fruitImage) {
this.fruitName = fruitName;
this.fruitImage = fruitImage;
}
public String getFruitName() {
return fruitName;
}
public void setFruitName(String fruitName) {
this.fruitName = fruitName;
}
public int getFruitImage() {
return fruitImage;
}
public void setFruitImage(int fruitImage) {
this.fruitImage = fruitImage;
}
private String fruitName;
private int fruitImage;
}
创建FruitAdapter
package cn.edu.zufe.appsecond.adapter;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.List;
import cn.edu.zufe.appsecond.bean.Fruit;
import cn.edu.zufe.appsecond.R;
public class FruitAdapter2 extends RecyclerView.Adapter<FruitAdapter2.ViewHolder> {
private List<Fruit> mFruitList;
static class ViewHolder extends RecyclerView.ViewHolder {
ImageView fruitImage;
TextView fruitName;
public ViewHolder(@NonNull View itemView) {
super(itemView);
fruitImage = (ImageView) itemView.findViewById(R.id.iv_fruit);
fruitName = (TextView) itemView.findViewById(R.id.tv_fruit);
}
}
public FruitAdapter2(List<Fruit> fruitList) {
mFruitList = fruitList;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull 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
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
Fruit fruit = mFruitList.get(position);
holder.fruitImage.setImageResource(fruit.getFruitImage());
holder.fruitName.setText(fruit.getFruitName());
}
@Override
public int getItemCount() {
return mFruitList.size();
}
}
主活动类
package cn.edu.zufe.appsecond;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.DefaultItemAnimator;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.recyclerview.widget.SimpleItemAnimator;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
import cn.edu.zufe.appsecond.adapter.FruitAdapter;
import cn.edu.zufe.appsecond.adapter.FruitAdapter2;
import cn.edu.zufe.appsecond.bean.Fruit;
public class MainActivity extends AppCompatActivity {
private static String TAG = "cn.edu.zufe.appsecond.MainActivity";
private ListView lv_fruit;
private List<Fruit> fruitList = new ArrayList<>();
private FruitAdapter2 fruitAdapter2;
private RecyclerView recyclerView;
private LinearLayoutManager linearLayoutManager;
private String[] fruitName = {
"apple","banana","cherry","grape","mango","orange","pear","pineapple","strawberry","watermelon"
};
private int[] fruitImageId = {
R.drawable.apple_pic,R.drawable.banana_pic,R.drawable.cherry_pic,R.drawable.grape_pic,R.drawable.mango_pic,R.drawable.orange_pic,
R.drawable.pear_pic,R.drawable.pineapple_pic,R.drawable.strawberry_pic,R.drawable.watermelon_pic
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initFruit(fruitName, fruitImageId);
recyclerView = (RecyclerView)findViewById(R.id.rv_fruit);
linearLayoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(linearLayoutManager);
fruitAdapter2 = new FruitAdapter2(fruitList);
recyclerView.setAdapter(fruitAdapter2);
}
private void initFruit(String[] names, int[] images) {
Fruit fruit;
for(int i=0; i<names.length; i++){
fruit = new Fruit(names[i], images[i]);
fruitList.add(fruit);
}
}
}
效果图
RecycleView横向滚动
修改fruit_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/iv_fruit"
android:layout_gravity="center_horizontal">
</ImageView>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/tv_fruit"
android:layout_gravity="center_horizontal">
</TextView>
</LinearLayout>
MainActivity种添加
linearLayoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
效果
瀑布流布局
MainActivity增加一个函数
private String getRandomName(String name){
String randomName = new String();
Random random = new Random();
for(int i=0; i<random.nextInt(20); i++){
randomName += name;
}
return randomName;
}
修改initFruit函数
private void initFruit(String[] names, int[] images) {
Fruit fruit;
for(int i=0; i<names.length; i++){
fruit = new Fruit(getRandomName(names[i]), images[i]);
fruitList.add(fruit);
}
}
修改MainActivity
staggeredGridLayoutManager = new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL);
recyclerView.setLayoutManager(staggeredGridLayoutManager);
效果
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