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;
        }
    }

context.getPackageManager () .getInstalledApplications (PackageManager.GET_META_DATA); 应该返回所有已安装应用程序的列表，但在android 11中，它只返回系统应用程序的列表。要获得所有应用程序(系统+用户)的列表，我们需要为应用程序提供额外的权限

< uses-permission android: name = " android.permission.QUERY_ALL_PACKAGES " / >

获取已安装的非系统应用程序列表

public static void installedApps()
{
    List<PackageInfo> packList = getPackageManager().getInstalledPackages(0);
    for (int i=0; i < packList.size(); i++)
    {
        PackageInfo packInfo = packList.get(i);
        if (  (packInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) == 0)
        {
            String appName = packInfo.applicationInfo.loadLabel(getPackageManager()).toString();
            Log.e("App № " + Integer.toString(i), appName);
        }
    }
}

下面是使用PackageManager的一种更简洁的方式

final PackageManager pm = getPackageManager();
//get a list of installed apps.
List<ApplicationInfo> packages = pm.getInstalledApplications(PackageManager.GET_META_DATA);

for (ApplicationInfo packageInfo : packages) {
    Log.d(TAG, "Installed package :" + packageInfo.packageName);
    Log.d(TAG, "Source dir : " + packageInfo.sourceDir);
    Log.d(TAG, "Launch Activity :" + pm.getLaunchIntentForPackage(packageInfo.packageName)); 
}
// the getLaunchIntentForPackage returns an intent that you can use with startActivity() 

更多信息请点击这里http://qtcstation.com/2011/02/how-to-launch-another-app-from-your-app/

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++;

}
}

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);