阅读《Android 从入门到精通》（23）——列表视图

Posted 2023-01-12 SweetLoverFT

列表视图（ListView）

android.widget.ViewGroup;
android.widget.AdapterView;
android.widget.ListView;

继承于 AdapterView 类，通常需要和列表适配器 ListAdapter 配合起来使用

ListView 类方法

ListView 示例

完整工程：http://download.csdn.net/detail/sweetloveft/9426612

整个工程和 GridView 相比没有变化，主要就是布局的 activity_main.xml 发生了变化，另一个就是 GridView 变成了 ListView。下面我们说一下 Adapter 分类：
（1）数组适配器 ArrayAdapter：常用于显示一行文字；
（2）简单游标适配器 SimpleCursorAdapter：专门用于数据库的适配器，可以将数据库中的内容以列表的形式显示；
（3）简单适配器 SimpleAdapter：扩充性强、灵活度高，可以通过该适配器定义各种效果；
（4）基本适配器 BaseAdapter：提供了适配器的基本操作。

1.MainActivity.java

package com.sweetlover.activity;

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

import com.sweetlover.listview.R;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends Activity 

	class SelfAdapter extends BaseAdapter 

		private class Grider 
			TextView textView;
		

		private Context context = null;
		private List<String> lstGrid = null;
		private LayoutInflater layoutInflater = null;

		public SelfAdapter(Context context) 
			super();
			this.context = context;
		

		public void setList(List<String> lstGrid) 
			this.lstGrid = lstGrid;
			layoutInflater = (LayoutInflater) context
					.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
		

		@Override
		public int getCount() 
			// TODO Auto-generated method stub
			return lstGrid.size();
		

		@Override
		public Object getItem(int position) 
			// TODO Auto-generated method stub
			return lstGrid.get(position);
		

		@Override
		public long getItemId(int position) 
			// TODO Auto-generated method stub
			return position;
		

		@Override
		public View getView(int position, View convertView, ViewGroup parent) 
			// TODO Auto-generated method stub
			Grider gridHolder = null;

			if (convertView != null) 
				gridHolder = (Grider) convertView.getTag();
			 else 
				gridHolder = new Grider();
				convertView = layoutInflater.inflate(R.layout.grid, null);
				gridHolder.textView = (TextView) convertView
						.findViewById(R.id.textView);
				convertView.setTag(gridHolder);
			
			gridHolder.textView.setText(lstGrid.get(position));

			return convertView;
		
	

	private ListView listView = null;
	private List<String> lstGrid = null;
	private SelfAdapter gridAdapter = null;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) 
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		int i;
		listView = (ListView)findViewById(R.id.listView);
		lstGrid = new ArrayList<String>();
		gridAdapter = new SelfAdapter(this);
		for (i = 1; i <= 15; i++) 
			lstGrid.add("Grid_" + i);
		
		gridAdapter.setList(lstGrid);
		listView.setAdapter(gridAdapter);
	

2.activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<ListView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/listView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center" />

3.grid.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:paddingBottom="8dp" >
    
    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:contentDescription="@string/content_description"
        android:src="@drawable/icon" />
    
    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_below="@id/imageView" />
</RelativeLayout>

4.AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.sweetlover.listview"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="19" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity android:name="com.sweetlover.activity.MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
    </application>

</manifest>