@Override
  protected void onResume() {
    /**
     * 设置为横屏 
     */
    if (getRequestedOrientation() != ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE) {
      setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
    }
    super.onResume();
  }

android:launchMode="singleTask" android:screenOrientation="portrait">

@Override
  protected void onResume() {
    /**
     * 设置为横屏 
     */
    if (getRequestedOrientation() != ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE) {
      setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
    }
    super.onResume();
  }

android:launchMode="singleTask" android:screenOrientation="landscape">