通过packgername 启动activity

   try {

      PackageManager manager=mContext.getPackageManager();
      Intent lanuch = new Intent();
      lanuch = manager.getLaunchIntentForPackage("com.cyanogenmod.filemanager");
      lanuch.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
      mContext.startActivity(lanuch);
   } catch (ActivityNotFoundException e) {
      Slog.w(TAG, "No activity to handle assist action.", e);
      }