通用的Adapter

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <ListView
        android:id="@+id/lv_main_apps"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1" >
    </ListView>
</LinearLayout>

item_app.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="70dp"
    android:minHeight="70dp"
    android:orientation="horizontal"
    android:gravity="center_vertical">

    <ImageView
        android:id="@+id/iv_item_icon"
        android:layout_width="70dp"
        android:layout_height="70dp"
        android:src="@drawable/ic_launcher" />

    <TextView
        android:id="@+id/tv_item_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="TextView" />

</LinearLayout>

AppInfo

package com.example.app3_listview;

import android.graphics.drawable.Drawable;

public class AppInfo {

	private Drawable icon;
	private String appName;
	private String packageName;

	public AppInfo(Drawable icon, String appName, String packageName) {
		super();
		this.icon = icon;
		this.appName = appName;
		this.packageName = packageName;
	}

	public AppInfo() {
		super();
	}

	public Drawable getIcon() {
		return icon;
	}

	public void setIcon(Drawable icon) {
		this.icon = icon;
	}

	public String getAppName() {
		return appName;
	}

	public void setAppName(String appName) {
		this.appName = appName;
	}

	public String getPackageName() {
		return packageName;
	}

	public void setPackageName(String packageName) {
		this.packageName = packageName;
	}

	@Override
	public String toString() {
		return "AppInfo [icon=" + icon + ", appName=" + appName
				+ ", packageName=" + packageName + "]";
	}

}

MainActivity

package com.example.app3_listview;

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

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;

import com.example.adapter.base.CommonBaseAdapter;
import com.example.adapter.base.ViewHolder;

public class MainActivity extends Activity {

	private ListView lv_main_apps;
	private List<AppInfo> data;
	private MyAdapter adapter;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		// 加载视图--只有一个listview
		setContentView(R.layout.activity_main);
		// 获取id
		lv_main_apps = (ListView) findViewById(R.id.lv_main_apps);

		// 得到数据
		data = getAllAppInfos();

		// 创建adapter
		adapter = new MyAdapter(this, data, R.layout.item_app);

		// 设置adapter显示
		lv_main_apps.setAdapter(adapter);

		// 设置每项(item)的点击监听
		lv_main_apps
				.setOnItemClickListener(new AdapterView.OnItemClickListener() {
					@Override
					public void onItemClick(AdapterView<?> parent, View view,
							int position, long id) {// position 点击的下标
						// 得到数据
						AppInfo appInfo = data.get(position);
						String appName = appInfo.getAppName();
						// 显示
						Toast.makeText(MainActivity.this, appName, 0).show();
					}
				});
	}

	/*
	 * 得到手机中所有应用信息的列表 AppInfo
	 */
	protected List<AppInfo> getAllAppInfos() {

		List<AppInfo> list = new ArrayList<AppInfo>();
		// 得到应用的packgeManager
		PackageManager packageManager = getPackageManager();
		// 创建一个主界面的intent
		Intent intent = new Intent();
		intent.setAction(Intent.ACTION_MAIN);
		intent.addCategory(Intent.CATEGORY_LAUNCHER);
		// 得到包含应用信息的列表
		List<ResolveInfo> ResolveInfos = packageManager.queryIntentActivities(
				intent, 0);
		// 遍历
		for (ResolveInfo ri : ResolveInfos) {
			// 得到包名
			String packageName = ri.activityInfo.packageName;
			// 得到图标
			Drawable icon = ri.loadIcon(packageManager);
			// 得到应用名称
			String appName = ri.loadLabel(packageManager).toString();
			// 封装应用信息对象
			AppInfo appInfo = new AppInfo(icon, appName, packageName);
			// 添加到list
			list.add(appInfo);
		}
		return list;
	}

	/**
	 * 继承自CommonBaseAdapter的adapter类
	 */
	class MyAdapter extends CommonBaseAdapter<AppInfo> {

		public MyAdapter(Context context, final List<AppInfo> data, int layoutId) {
			super(context, data, layoutId, new Convert() {
				@Override
				public void convert(ViewHolder holder, int position) {

					AppInfo appInfo = data.get(position);
					holder.setText(R.id.tv_item_name, appInfo.getAppName()).setImageDrawable(R.id.iv_item_icon,appInfo.getIcon());
				}
			});
		}

	}
}

CommonBaseAdapter

package com.example.adapter.base;

import java.util.List;

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

/**
 * 通用的baseAdapter
 */
public abstract class CommonBaseAdapter<T> extends BaseAdapter {

	private Context context;
	private List<T> data;
	private int layoutId;
	public Convert convert;

	/**
	 * 设置视图数据的抽象方法, 由具体的adapter子类来实现
	 */
	public interface Convert{
		void convert(ViewHolder holder, int position);
	}
	public CommonBaseAdapter(Context context, List<T> data, int layoutId,Convert convert) {
		this.context = context;
		this.data = data;
		this.layoutId = layoutId;
		this.convert = convert;
	}

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

	@Override
	public T getItem(int position) {
		return data.get(position);
	}

	@Override
	public long getItemId(int position) {
		return 0;
	}

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		//得到Viewholder对象
		ViewHolder holder = ViewHolder.getHolder(context, convertView,
				layoutId);
		//调用未实现的抽象方法设置数据
		convert.convert(holder, position);
		//返回holder中的convertView
		return holder.getConvertView();
	}

}

ViewHolder

package com.example.adapter.base;

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.util.SparseArray;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;

/**
 * 通用的ViewHolder类
 */
public class ViewHolder {

	// 代表当前行的view对象
	private View itemConvertView;
	// 用来替代Map<Integer,Object>的容器, 效率比map高
	private SparseArray<View> views;

	/*******************************************************************
	 * 得到ViewHolder对象 context--layoutId：这个是用来构造时候，需要动态加载布局文件
	 * convertview:是可复用的item布局
	 */
	public static ViewHolder getHolder(Context context, View convertView,
			int layoutId) {
		/**
		 * 如果没有可复用的布局，就创建本类对象 如果有的话，就通过getTag获取
		 * */
		if (convertView == null) {
			return new ViewHolder(context, layoutId);
		} else {
			ViewHolder holder = (ViewHolder) convertView.getTag();
			return holder;
		}
	}

	/**
	 * 构造方法 加载布局文件，将本类标记即viewholder保存到itemConvertView中
	 */
	private ViewHolder(Context context, int layoutId) {
		this.itemConvertView = View.inflate(context, layoutId, null);
		this.itemConvertView.setTag(this);
		views = new SparseArray<View>();
	}

	/**
	 * 得到当前对应的convertView
	 */
	public View getConvertView() {
		return itemConvertView;
	}

	/*************************
	 * %%%%%%%%%%%%******************************** 根据视图id得到对应的视图对象
	 */
	public <T extends View> T getView(int viewId) {
		View view = views.get(viewId);
		if (view == null) {
			view = itemConvertView.findViewById(viewId);
			views.put(viewId, view);
		}
		return (T) view;
	}

	//

	/**
	 * 设置文本数据
	 */
	public ViewHolder setText(int viewId, String text) {
		TextView textView = getView(viewId);
		textView.setText(text);
		return this;
	}

	/**
	 * 设置drawable图片
	 */
	public ViewHolder setImageDrawable(int viewId, Drawable drawable) {
		ImageView imageView = getView(viewId);
		imageView.setImageDrawable(drawable);
		return this;
	}

	/**
	 * 设置资源图片
	 */
	public ViewHolder setImageResource(int viewId, int resourceId) {
		ImageView imageView = getView(viewId);
		imageView.setImageResource(resourceId);
		return this;
	}
}

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