PackageManager是个非常好的东西，其他的详细的细节等日后有时间整理
PackageManager的功能：
安装，卸载应用
查询permission相关信息
查询Application相关信息(application，activity，receiver，service，provider及相应属性等）
查询已安装应用
增加，删除permission
清除用户数据、缓存，代码段等
我们可以用PackageManager来显示系统安装的应用程序列表或者系统程序列表
package eoe.appshow;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import Android.app.Activity;
import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
public class AppShowActivity extends Activity {
ListView lv;
MyAdapter adapter;
ArrayList<HashMap<String, Object>> items = new ArrayList<HashMap<String, Object>>();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
lv = (ListView)findViewById(R.id.lv);
//得到PackageManager对象
PackageManager pm = getPackageManager();
//得到系统安装的所有程序包的PackageInfo对象
//List<ApplicationInfo> packs = pm.getInstalledApplications(0);
List<PackageInfo> packs = pm.getInstalledPackages(0);
for(PackageInfo pi:packs)
{
HashMap<String, Object> map = new HashMap<String, Object>();
//显示用户安装的应用程序，而不显示系统程序
// if((pi.applicationInfo.flags&ApplicationInfo.FLAG_SYSTEM)==0&&
// (pi.applicationInfo.flags&ApplicationInfo.FLAG_UPDATED_SYSTEM_APP)==0)
// {
// //这将会显示所有安装的应用程序，包括系统应用程序
// map.put("icon", pi.applicationInfo.loadIcon(pm));//图标
// map.put("appName", pi.applicationInfo.loadLabel(pm));//应用程序名称
// map.put("packageName", pi.applicationInfo.packageName);//应用程序包名
// //循环读取并存到HashMap中，再增加到ArrayList上，一个HashMap就是一项
// items.add(map);
// }
//这将会显示所有安装的应用程序，包括系统应用程序
map.put("icon", pi.applicationInfo.loadIcon(pm));//图标
map.put("appName", pi.applicationInfo.loadLabel(pm));//应用程序名称
map.put("packageName", pi.applicationInfo.packageName);//应用程序包名
//循环读取并存到HashMap中，再增加到ArrayList上，一个HashMap就是一项
items.add(map);
}
/**
* 参数：Context
* ArrayList(item的集合)
* item的layout
* 包含ArrayList中的HashMap的key的数组
* key所对应的值的相应的控件id
*/
adapter = new MyAdapter(this, items, R.layout.piitem,
new String[]{"icon", "appName", "packageName"},
new int[]{R.id.icon, R.id.appName, R.id.packageName});
lv.setAdapter(adapter);
}
}
class MyAdapter extends SimpleAdapter
{
private int[] appTo;
private String[] appFrom;
private ViewBinder appViewBinder;
private List<? extends Map<String, ?>> appData;
private int appResource;
private LayoutInflater appInflater;
public MyAdapter(Context context, List<? extends Map<String, ?>> data,
int resource, String[] from, int[] to) {
super(context, data, resource, from, to);
appData = data;
appResource = resource;
appFrom = from;
appTo = to;
appInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public View getView(int position, View convertView, ViewGroup parent){
return createViewFromResource(position, convertView, parent, appResource);
}
private View createViewFromResource(int position, View convertView, ViewGroup parent, int resource){
View v;
if(convertView == null)
{
v = appInflater.inflate(resource, parent,false);
final int[] to = appTo;
final int count = to.length;
final View[] holder = new View[count];
for(int i = 0; i < count; i++)
{
holder[i] = v.findViewById(to[i]);
}
v.setTag(holder);
}else
{
v = convertView;
}
bindView(position, v);
return v;
}
private void bindView(int position, View view)
{
final Map dataSet = appData.get(position);
if(dataSet == null)
{
return;
}
final ViewBinder binder = appViewBinder;
final View[] holder = (View[])view.getTag();
final String[] from = appFrom;
final int[] to = appTo;
final int count = to.length;
for(int i = 0; i < count; i++)
{
final View v = holder[i];
if(v != null)
{
final Object data = dataSet.get(from[i]);
String text = data == null ? "":data.toString();
if(text == null)
{
text = "";
}
boolean bound = false;
if(binder != null)
{
bound = binder.setViewValue(v, data, text);
}
if(!bound)
{
/**
* 自定义适配器，关在在这里，根据传递过来的控件以及值的数据类型，
* 执行相应的方法，可以根据自己需要自行添加if语句。另外，CheckBox等
* 集成自TextView的控件也会被识别成TextView，这就需要判断值的类型
*/
if(v instanceof TextView)
{
//如果是TextView控件，则调用SimpleAdapter自带的方法，设置文本
setViewText((TextView)v, text);
}else if(v instanceof ImageView){
//如果是ImageView控件，调用自己写的方法，设置图片
setViewImage((ImageView)v, (Drawable)data);
}else{
throw new IllegalStateException(v.getClass().getName() + " is not a " + "view that can be bounds by this SimpleAdapter");
}
}
}
}
}
public void setViewImage(ImageView v, Drawable value){
v.setImageDrawable(value);
}
}