Question

我写了一个代码，用户可以拍照或从他的库中选择。我曾打算打开画廊/相机，它从画廊返回位图或文件的路径。我收到的数据尝试将其保存在接口上，但由于某种原因，它总是崩溃，因为它为空。

如果接口实际获得位图/文件路径，我不明白该接口如何变为空。

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);
   }

 }

我运行该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”中实现接口解决了问题，并调用了该接口的func并传递了数据，它就起作用了！

    //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);
}

那就是我要做的

Answer 1

您的MainActivity（所有片段所依赖的活动）需要实现接口，您需要在Fragment

中使用该接口

现在的问题是如何将数据从Activity传输到Fragment，为此，您需要使用Fragment的findFragmentById方法，看一看示例我已将数据从Activity传输到Fragment

public class MainActivity extends AppCompatActivity implements OnPhotoReceivedListener {


    @Override
    public void getImagePath(String name) {

        YOUR_FRAGMENT fragment = (YOUR_FRAGMENT) getFragmentManager().findFragmentById(R.id.fragment_container);
        fragment.setDataForInterface(name);  //// THESE METHOD , YOU NEED TO CREATE ON THE FRAGMENT

    }
}

在onCreateView内，您需要像下面这样初始化OnPhotoReceivedListener接口

 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 ");
        }
    }

您需要创建一种方法，该方法将从父Activity到Fragment的数据中获取数据

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

Android-存储活动结果返回null

1 个答案: