//检查某个应用是否安装     public static boolean checkAPP(Context context, String packageName) {         if (packageName == null || "".equals(packageName))             return false;         try {             ApplicationInfo info = context.getPackageManager()                     .getApplicationInfo(packageName,                             PackageManager.GET_UNINSTALLED_PACKAGES);             return true;         } catch (NameNotFoundException e) {             return false;         }     }