DialogFragment的OnDismissListener

CaptureActivity中扫码会显示一个DialogFragment，显示扫码得到的操作选项 。DialogFragment中有个close按钮，点了隐藏，同时会调用handler.restartPreviewAndDecode(),使得可以重新扫码。现在遇到问题是显示了DialogFragment，点击手机返回按钮，一样会隐藏DialogFragment。但是不会调用handler.restartPreviewAndDecode()导致无法重复扫码。重写onBackPress或onKeyDown方法也不行，因为DialogFragment的隐藏是先于BackPress的。

解决方法：public class CaptureActivity extends AppCompatActivity implements DialogInterface.OnDismissListener

@Override

public void onDismiss(DialogInterface dialog) {

  continuePreview();

}

重写DialogFragment ：

@Override

public void onDismiss(final DialogInterface dialog) {

  super.onDismiss(dialog);

  final Activity activity = getActivity();

  if (activity instanceof DialogInterface.OnDismissListener) {

  ((DialogInterface.OnDismissListener) activity).onDismiss(dialog);

  }

}

参考：

http://stackoverflow.com/questions/23786033/dialogfragment-and-ondismiss