Android-存储活动结果返回null

我写了一个代码，用户可以拍照或从他的图书馆中选择。 我使用intent打开gallery/camera，它返回位图或gallery中文件的路径。我试图将收到的数据保存到接口上，但由于某些原因，它总是崩溃，因为它的值为null

我不明白如果接口实际得到位图/文件路径，它怎么会变成null

代码

     public class ChangeProfileImgDialog extends DialogFragment {

private static final String TAG = "ChangePhotoDialog";

public static final int  CAMERA_REQUEST_CODE = 1;//random number
public static final int PICKFILE_REQUEST_CODE = 0;//random number

public ChangeProfileImgDialog() {
    // Required empty public constructor
}

public interface OnPhotoReceivedListener{
    public void getImagePath(Uri imagePath);
    public void getImageBitmap(Bitmap bitmap);
}

OnPhotoReceivedListener mOnPhotoReceived;


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View v = inflater.inflate(R.layout.fragment_change_profile_img_dialog, container, false);

    //Initialize the textview for choosing an image from memory
    TextView selectPhoto = (TextView) v.findViewById(R.id.dialogChoosePhoto);
    selectPhoto.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Log.d(TAG, "onClick: accessing phones memory.");
            Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
            intent.setType("image/*");
            startActivityForResult(intent, PICKFILE_REQUEST_CODE);
        }
    });


    //Initialize the textview for choosing an image from memory
    TextView takePhoto = (TextView) v.findViewById(R.id.dialogOpenCamera);
    takePhoto.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Log.d(TAG, "onClick: starting camera");
            Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            startActivityForResult(cameraIntent, CAMERA_REQUEST_CODE);
        }
    });

    return v;

}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    /*
    Results when selecting new image from phone memory
     */
    if(requestCode == PICKFILE_REQUEST_CODE && resultCode == Activity.RESULT_OK){
        Uri selectedImageUri = data.getData();
        Log.d(TAG, "onActivityResult: image: " + selectedImageUri);

        //send the uri and fragment to the interface
        mOnPhotoReceived.getImagePath(selectedImageUri);
        getDialog().dismiss();

    }

    else if(requestCode == CAMERA_REQUEST_CODE && resultCode == Activity.RESULT_OK){
        Log.d(TAG, "onActivityResult: done taking a photo.");

        Bitmap bitmap;
        bitmap = (Bitmap) data.getExtras().get("data");
        //send the bitmap and fragment to the interface
        mOnPhotoReceived.getImageBitmap(bitmap);
        getDialog().dismiss();
    }
}

@Override
public void onAttach(Context context) {
    try{
        mOnPhotoReceived = (OnPhotoReceivedListener) getActivity();
    }catch (ClassCastException e){
        Log.e(TAG, "onAttach: ClassCastException", e.getCause() );
    }
    super.onAttach(context);
   }

 }

我运行应用程序的设备是小米A1-我不知道它是否相关

编辑

我已经通过在“MainActivity”中实现接口解决了这个问题，并调用接口的func，传递数据，它就可以工作了

    //transfer the imagepath to MyAccountFragment
@Override
public void getImagePath(Uri imagePath) {
    Log.d(TAG,imagePath.toString());
    MyAccountFragment fragment = new MyAccountFragment();
    fragment.getImagePath(imagePath);
}

//transfer the bitmap to MyAccountFragment
@Override
public void getImageBitmap(Bitmap bitmap) {
    Log.d(TAG,bitmap.toString());
    MyAccountFragment fragment = new MyAccountFragment();
    fragment.getImageBitmap(bitmap);
}

这就是我所需要做的

您的主要活动（所有片段所依赖的活动）需要实现在

片段中使用的接口

现在的问题是如何将数据从
Activity
传输到
Fragment
，为此，需要使用片段的
findFragmentById
方法，看看我将数据从
Activity
传输到
Fragment
的示例

在您的
onCreateView
中，您需要初始化
OnPhotoReceivedListener
界面，如下所示

 OnPhotoReceivedListener mOnPhotoReceived;

 @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
          /**
           * This is the main error which u are doing
           */

        try {
            mOnPhotoReceived = (OnPhotoReceivedListener ) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString()
                    + " must implement MyInterface ");
        }
    }

您需要创建一个方法，该方法将从父级
活动
到
片段

   public void setDataForInterface(String yourData) {
           /**
            * THIS IS YOUR DATA WHICH IS COME FROM THE PARENT ACTIVITY
            */
    }

我添加了那行代码，但它使我的应用程序崩溃。实际上，我在“onAttach”@E.Bolandian中使用了这行代码。请检查我的更新解决方案。我已经在onAttach（）中添加了代码，请检查solution@Overridepublic void onAttach（上下文上下文）{super.onAttach（上下文）；尝试{mOnPhotoReceived=（onphotoreceivedstener）getActivity（）；}catch（ClassCastException e）{Log.e（标记，“onAttach:ClassCastException”，e.getCause（）；}}crash@E.Bolandian看一看解决方案…我的一个问题是，为什么需要interace来保存图像路径/位图？我想我已经找到了问题，但我不知道如何解决它。应用程序崩溃，因为mOnPhotoReceived为空-我不知道，如果我在“onAttach”中初始化它，是否已解决问题..请参考下面更新的解决方案。。。
   public void setDataForInterface(String yourData) {
           /**
            * THIS IS YOUR DATA WHICH IS COME FROM THE PARENT ACTIVITY
            */
    }