Android ListView自动生成列表条目的实例

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent">

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

</LinearLayout>

package com.example.sample_6_4;

import android.app.Dialog;
import android.graphics.Color;
import android.preference.DialogPreference;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;

public class ListActivity extends AppCompatActivity {
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_list);
  ListView lv = (ListView)findViewById(R.id.listview);
  //做一个适配器来使用ListView
  lv.setAdapter(new MyAdapter());
 }
 class MyAdapter extends BaseAdapter{
  @Override
  //返回条目的个数，列表的条目，例如一个屏幕显示多少条
  public int getCount(){
   return 20;
  }
  @Override
  //确定每个条目的布局和内容，position代表条目的位置，从0开始
  public View getView(int position, View converView, ViewGroup parent){
   TextView tv = new TextView(ListActivity.this);
   tv.setText("条目" + position);
   tv.setTextSize(23);
   tv.setTextColor(Color.BLUE);
   return tv;
  }
  @Override
  public Object getItem(int position){
   return null;
  }
  @Override
  public long getItemId(int position){
   return 0;
  }
 }
}