Android移动应用开发之ListView和RecyclerView的简单使用

Posted 2022-09-26 Icy Hunter

文章目录

• ListView主要文件目录
• • Bean
  • MainActivity
  • MyAdapter
  • activity_main.xml
  • list_item.xml
  • 运行
• RecyclerView
• • 配置依赖
  • 主要文件目录
  • • Bean
    • MainActivity
    • MyAdapter
    • activity_main.xml
    • recyclerview_item.xml
    • 运行

ListView主要文件目录

Bean

用于存放数据

package icy.hunter;

public class Bean 
    String name;

    public String getName() 
        return name;
    

    public void setName(String name) 
        this.name = name;
    

MainActivity

主界面的代码

package icy.hunter;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;

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

public class MainActivity extends AppCompatActivity 
    private List<Bean> data = new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

//        获取数据
        for(int i=0; i< 100; i++)
            Bean bean = new Bean();
            bean.setName("Hunter"+i);
            data.add(bean);
        

//        拿到对象
        ListView listView = findViewById(R.id.lv);
//        填充数据
        listView.setAdapter(new MyAdapter(data, this));
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() 
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) 
                Log.e("TAG", "onclickitem"+position);
            
        );
    

MyAdapter

用于ListView各个单位的数据填充和事件处理。

package icy.hunter;

import android.content.Context;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;


import java.util.List;

public class MyAdapter extends BaseAdapter 

    private List<Bean> data;
    private Context context;

    public MyAdapter(List<Bean> data, Context context) 
        this.data = data;
        this.context = context;
    

    @Override
    public int getCount() 
        return data.size();
    

    @Override
    public Object getItem(int position) 
        return null;
    

    @Override
    public long getItemId(int position) 
        return position;
    

    @Override
    public View getView(int position, View convertView, ViewGroup parent) 
        ViewHolder viewHolder;
        if(convertView == null)
            viewHolder = new ViewHolder();
            //返回item条目
            convertView =  LayoutInflater.from(context).inflate(R.layout.list_item, parent, false);
            viewHolder.textView = convertView.findViewById(R.id.tv);
            convertView.setTag(viewHolder);
        else
            viewHolder = (ViewHolder) convertView.getTag();
        

        viewHolder.textView.setText(data.get(position).getName());
        Log.e("TAG", "getView" + position);

        return convertView;
    

    private static final class ViewHolder
        TextView textView;
    

activity_main.xml

主界面布局，ListView放个壳

<?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"
    >
    <ListView
        android:id="@+id/lv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</LinearLayout>

list_item.xml

list_view里的元素界面。

<?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"
    >
    <TextView
        android:id="@+id/tv"
        android:textSize="40sp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
</LinearLayout>

运行

进去就是排列item整齐的listview

滑动会发现界面出现了那个item就会调用一次MyAdapter里的getView方法。
点击

控制台输出

说明事件设置成功。

RecyclerView

配置依赖

并没自带，需要自己加一下

//    添加依赖包
    implementation 'androidx.recyclerview:recyclerview-selection:1.1.0'

点击然后添加一下，就可以了。

主要文件目录

Bean

和上面一样

package icy.hunter;

public class Bean 
    String name;

    public String getName() 
        return name;
    

    public void setName(String name) 
        this.name = name;
    

MainActivity

可以设置不同布局

package icy.hunter;

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.recyclerview.widget.StaggeredGridLayoutManager;

import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridLayout;
import android.widget.LinearLayout;
import android.widget.ListView;

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

public class MainActivity extends AppCompatActivity 
    private List<Bean> data = new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

//        获取数据
        for (int i = 0; i < 100; i++) 
            Bean bean = new Bean();
            bean.setName("Hunter" + i);
            data.add(bean);
        

        RecyclerView recyclerView = findViewById(R.id.rv);

        线性布局
//        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
//        recyclerView.setLayoutManager(linearLayoutManager);

        网格布局
//        GridLayoutManager gridLayoutManager = new GridLayoutManager(this, 3);
//        recyclerView.setLayoutManager(gridLayoutManager);

        StaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(3,
                LinearLayout.VERTICAL);
        recyclerView.setLayoutManager(staggeredGridLayoutManager);

        MyAdapter myAdapter = new MyAdapter(data, this);
        recyclerView.setAdapter(myAdapter);

        myAdapter.setRecyclerItemClickListener(new MyAdapter.OnRecyclerItemClickListener() 
            @Override
            public void onRecyclerItemClick(int position) 
                Log.e("TAG", "Click" + position);
            
        );
    

MyAdapter

需要自己设置事件监听

package icy.hunter;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;


import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import java.util.List;

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder>
    private List<Bean> data;
    private Context context;

    public MyAdapter(List<Bean> data, Context context) 
        this.data = data;
        this.context = context;
    


    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) 
        View view = View.inflate(context, R.layout.recyclerview_item, null);
        return new MyViewHolder(view);
    

    @Override
    public void onBindViewHolder(@NonNull MyViewHolder holder, int position) 
            holder.tv.setText(data.get(position).getName());
    

    @Override
    public int getItemCount() 
        return data == null ? 0 : data.size();
    

    public class MyViewHolder extends RecyclerView.ViewHolder 
        private TextView tv;
        public MyViewHolder(@NonNull View itemView) 
            super(itemView);
            tv = itemView.findViewById(R.id.tv);
            itemView.setOnClickListener(new View.OnClickListener() 
                @Override
                public void onClick(View v) 
                    if(mOnItemClickListener != null)
                        mOnItemClickListener.onRecyclerItemClick(getAdapterPosition());
                    
                
            );

        
    

    private OnRecyclerItemClickListener mOnItemClickListener;

    public void setRecyclerItemClickListener(OnRecyclerItemClickListener listener)
        mOnItemClickListener = listener;
    

    public interface OnRecyclerItemClickListener
        void onRecyclerItemClick(int position);
    

activity_main.xml

主界面布局

<?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"
    >
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</LinearLayout>

recyclerview_item.xml

布局里的item

<?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"
    >
    <TextView
        android:id="@+id/tv"
        android:textSize="40sp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
</LinearLayout>

运行

点击出现事件响应

事件设置成功。