private static boolean isThisASystemPackage(Context context, PackageInfo  packageInfo ) {
        try {
            PackageInfo sys = context.getPackageManager().getPackageInfo("android", PackageManager.GET_SIGNATURES);
            return (packageInfo != null && packageInfo.signatures != null &&
                    sys.signatures[0].equals(packageInfo.signatures[0]));
        } catch (NameNotFoundException e) {
            return false;
        }
    }

这里有一个很好的例子:

class PInfo {
    private String appname = "";
    private String pname = "";
    private String versionName = "";
    private int versionCode = 0;
    private Drawable icon;
    private void prettyPrint() {
        Log.v(appname + "\t" + pname + "\t" + versionName + "\t" + versionCode);
    }
}

private ArrayList<PInfo> getPackages() {
    ArrayList<PInfo> apps = getInstalledApps(false); /* false = no system packages */
    final int max = apps.size();
    for (int i=0; i<max; i++) {
        apps.get(i).prettyPrint();
    }
    return apps;
}

private ArrayList<PInfo> getInstalledApps(boolean getSysPackages) {
    ArrayList<PInfo> res = new ArrayList<PInfo>();        
    List<PackageInfo> packs = getPackageManager().getInstalledPackages(0);
    for(int i=0;i<packs.size();i++) {
        PackageInfo p = packs.get(i);
        if ((!getSysPackages) && (p.versionName == null)) {
            continue ;
        }
        PInfo newInfo = new PInfo();
        newInfo.appname = p.applicationInfo.loadLabel(getPackageManager()).toString();
        newInfo.pname = p.packageName;
        newInfo.versionName = p.versionName;
        newInfo.versionCode = p.versionCode;
        newInfo.icon = p.applicationInfo.loadIcon(getPackageManager());
        res.add(newInfo);
    }
    return res; 
}

获取所有应用程序:

    PackageManager pm = getContext().getPackageManager();
    List<ApplicationInfo> apps = pm.getInstalledApplications(0);

检查是否安装了应用程序，然后打开:

if((app.flags & (ApplicationInfo.FLAG_UPDATED_SYSTEM_APP | ApplicationInfo.FLAG_SYSTEM)) > 0) {
                String app_package = app.packageName;
Intent launchIntent = context.getPackageManager().getLaunchIntentForPackage(app_package);
context.startActivity(launchIntent);

public static List<ApplicationInfo> getApplications(Context context) {
    return context.getPackageManager().getInstalledApplications(PackageManager.GET_META_DATA);
}

你可以通过下面的代码找到Android设备中已安装的应用程序列表，“packageInfo”包含已安装的应用程序信息 在设备。我们可以为安装的应用程序检索Intent packageinfo对象可以使用startactivity(intent)来启动 应用程序。这取决于你如何组织UI或Listview 或显示数据表格。基于位置的点击事件，你可以检索意图 对象和启动活动意图。

final PackageManager pm = getPackageManager();

List<ApplicationInfo> packages = pm.getInstalledApplications(PackageManager.GET_META_DATA);


for (ApplicationInfo packageInfo : packages) 

{
 if(pm.getLaunchIntentForPackage(packageInfo.packageName)!= null &&   

                   !pm.getLaunchIntentForPackage(packageInfo.packageName).equals(""))


{

    System.out.println("Package Name :" + packageInfo.packageName);

    System.out.println("Launch Intent For Package :"   +  
                  pm.getLaunchIntentForPackage(packageInfo.packageName));

    System.out.println("Application Label :"   + pm.getApplicationLabel(packageInfo));

    System.out.println("Application Label :"   + 
                           pm.getApplicationIcon(packageInfo.packageName).toString());

    System.out.println("i : "+i);

    /*if(i==2)

    {
         startActivity(pm.getLaunchIntentForPackage(packageInfo.packageName));

     break;

    }*/

    i++;

}
}

下面是获取Android上安装的活动/应用程序列表的代码:

Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);
List<ResolveInfo> pkgAppsList = context.getPackageManager().queryIntentActivities( mainIntent, 0);

您将在ResolveInfo中获得启动应用程序所需的所有数据。你可以在这里检查ResolveInfo javadoc。