android studio写一个listView

先看一下改动的文件是哪些

然后做出的样子是什么样的：

两个drawable文件的内容很简单，就是定义了控件，代码如下：
main.xml

listItem.xml

然后是比较重要的mainActivity文件

package com.sgh.listview;

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 data = new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        for(int i = 0; i < 100; i++){
            Bean bean = new Bean();
            bean.setName("测试" + i);
            data.add(bean);//将创建的Bean对象放入List里面，List数据填充完毕
        }
        ListView listView = findViewById(R.id.lv);
        //数据怎么填充到ListView,要用到BaseAdapter
        listView.setAdapter(new MyAdpater(data,this));
        //设置点击事件
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView adapterView, View view, int i, long l) {
                Log.e("test","onItemClick: " + i);
            }
        });
    }
}

MyAdapter代码

package com.sgh.listview;

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 MyAdpater extends BaseAdapter {
    private List data;
    private Context context;

    public MyAdpater(List data, Context context) {
        this.data = data;
        this.context = context;
    }

    //获取总共数据
    @Override
    public int getCount() {
        return data.size();
    }

    @Override
    public Object getItem(int i) {
        return null;
    }

    @Override
    public long getItemId(int i) {
        return i;
    }
    //获取每一个条目
    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        ViewHolder viewHolder;
        //渲染的给view,Item是复用的，不断进行判断
        if(view == null){
            viewHolder = new ViewHolder();
            view = LayoutInflater.from(context).inflate(R.layout.list_item,viewGroup,false);
            viewHolder.textView = view.findViewById(R.id.tv);
            view.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) view.getTag();
        }
        viewHolder.textView.setText(data.get(i).getName());

        //打印观察
        Log.e("test","getView:" + i);
        return view;
    }
    //findViewById是很耗时的，所以我们新建一个类
    private final class ViewHolder{
        //Listitem里面有几个子控件，这里就几个属性
        TextView textView;


    }
}

Bean文件是每一个Item内容的属性的定义

package com.sgh.listview;

public class Bean {
    String name;

    public String getName() {
        return name;
    }

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

如果有看不懂的那个Adapter的，可以看看这个文章
BaseAdapter使用说明