ZXing IntentResult给出空值

Question

我正在使用ZXing库创建一个二维码扫描仪。.IntentResult为空值，并且扫描仪无法正常工作...请帮助...谢谢！

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    IntentResult result = IntentIntegrator.parseActivityResult(requestCode, resultCode, data);
    Toast.makeText(getActivity(), ""+result, Toast.LENGTH_SHORT).show();

    if(result != null){
        Toast.makeText(getActivity(), "in", Toast.LENGTH_SHORT).show();
        if(result.getContents() == null){
            Toast.makeText(getActivity(), "Scanning Cancelled", Toast.LENGTH_SHORT).show();
        }
        else{
             Toast.makeText(getActivity(), result.getContents(), Toast.LENGTH_LONG).show();

        }
    }
    else{
        super.onActivityResult(requestCode,resultCode, data);
        Toast.makeText(getActivity(), "out", Toast.LENGTH_SHORT).show();
    }
    super.onActivityResult(requestCode, resultCode, data);
}