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android - Marshmallow 和 Nougat+ 中的相机意图活动有何不同？

问题描述

我有以下代码在 android 6 中工作，但在 android 7+ 中使用它时，应用程序崩溃并出现 nullpointerexception。

Intent intentfile = new Intent("android.media.action.IMAGE_CAPTURE");
                    startActivityForResult(intentfile, SELECT_PHOTO);

在活动结果中，代码是

case SELECT_PHOTO:
            if (resultCode == RESULT_OK) {
                selectedImage =  data.getData();
                Picasso.get().load(selectedImage).fit().centerCrop().into(imageView);
                imgselect.setVisibility(Button.INVISIBLE);
                relativeLayout.setVisibility(RelativeLayout.VISIBLE);
                upload.setVisibility(Button.VISIBLE);

下一个代码是将选定的图像上传到服务器

String sourcepath = getRealPathFromURI(this, selectedImage);
            final String filename = sourcepath.substring(sourcepath.lastIndexOf("/") + 1);
            final String destinationpath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/DiaryApp/Images/";
            copyFile(sourcepath, filename, destinationpath);

            imageRef = storageRef.child(firebaseUser.getUid() + "/Images/" + filename);
            //creating and showing progress dialog
            progressDialog = new ProgressDialog(this);
            progressDialog.setMax(100);
            progressDialog.setMessage("Uploading...");
            progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
            progressDialog.show();
            progressDialog.setCancelable(false);
            //starting upload
            uploadTask = imageRef.putFile(selectedImage);
            // Observe state change events such as progress, pause, and resume
            uploadTask.addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() {
                @Override
                public void onProgress(UploadTask.TaskSnapshot taskSnapshot) {
                    double progress = (100.0 * taskSnapshot.getBytesTransferred()) / taskSnapshot.getTotalByteCount();
                    //sets and increments value of progressbar
                    progressDialog.incrementProgressBy((int) progress);
                }
            });
            // Register observers to listen for when the download is done or if it fails
            uploadTask.addOnFailureListener(new OnFailureListener() {
                @Override
                public void onFailure(@NonNull Exception exception) {
                    // Handle unsuccessful uploads
                    Toast.makeText(view.getContext(), "Error in uploading!", Toast.LENGTH_SHORT).show();
                    progressDialog.dismiss();
                }
            }).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                @Override
                public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                    // taskSnapshot.getMetadata() contains file metadata such as size, content-type, and download URL.
                    Uri downloadUrl = taskSnapshot.getDownloadUrl();
                    Toast.makeText(view.getContext(), "Upload successful", Toast.LENGTH_SHORT).show();
                    progressDialog.dismiss();
                    //showing the uploaded image in ImageView using the download url
                    Image image = new Image(editText.getText().toString(), "Image", "file:" + destinationpath + filename, downloadUrl + "", getDate(), getTime());
                    userDataRef.child("data").child(userDataRef.push().getKey()).setValue(image);
                    finish();

现在方法 getRealPathFromUri(this,selectedImage);

public String getRealPathFromURI(Context context, Uri contentUri) {
    Cursor cursor = null;
    try {
        if(contentUri.toString().contains("images")) //Error is here in this line {
            String[] proj = {MediaStore.Images.Media.DATA};
            cursor = context.getContentResolver().query(contentUri, proj, null, null, null);
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            return cursor.getString(column_index);
        }
        else if(contentUri.toString().contains("video")){
            String[] proj = {MediaStore.Video.Media.DATA};
            cursor = context.getContentResolver().query(contentUri, proj, null, null, null);
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Video.Media.DATA);
            cursor.moveToFirst();
            return cursor.getString(column_index);
        }
        else {
            return "Empty";
        }
    }



    finally {
        if (cursor != null) {
            cursor.close();
        }
    }
}

selectedimage 在 android 7+ 中为空，而在较小的 android 版本中它正在工作？

标签： androidandroid-camera-intent

解决方案

试试下面的代码 -

    Intent i = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
    File file=getOutputMediaFile(1);
    picUri = Uri.fromFile(file); // create
    i.putExtra(MediaStore.EXTRA_OUTPUT,picUri); // set the image file

    startActivityForResult(i, CAPTURE_IMAGE);

会在哪里getOutputMediaFile(int)——

 /** Create a File for saving an image */
private  File getOutputMediaFile(int type){
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
          Environment.DIRECTORY_PICTURES), "MyApplication");

/**Create the storage directory if it does not exist*/
if (! mediaStorageDir.exists()){
    if (! mediaStorageDir.mkdirs()){
        return null;
    }
}

/**Create a media file name*/
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
File mediaFile;
if (type == 1){
    mediaFile = new File(mediaStorageDir.getPath() + File.separator +
    "IMG_"+ timeStamp + ".png");
} else {
    return null;
}

return mediaFile;
}

最后——

  @Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == Activity.RESULT_OK) {
        Intent i;
        switch (requestCode) {
        case CAPTURE_IMAGE:
            //THIS IS YOUR Uri
            Uri uri=picUri; 
            break;
        }
    }   
}

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