从URI获取文件路径

我有用于图像文件的Uri。

我使用此代码从Uri获取文件路径：

public String getRealPathFromURI(Uri contentUri) {
    Cursor cursor = null;
    try {
        String[] proj = { MediaStore.Images.Media.DATA };
        cursor = mContext.getContentResolver().query(contentUri, proj, null, null, null);
        int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        return cursor.getString(column_index);
    } catch (Exception e) {
        Log.message(e.getMessage());
    } finally {
        if (cursor != null) {
            cursor.close();
        }
    }
    return null;
}

如果我从Gallery应用（Android 4.4.2，arm-emu）中选择图片，

uri.getPath = /external/images/media/16 and it work's fine (My file path: /storage/sdcard/Download/0_cf15a_7800a7e5_orig.jpg)

如果我从“文档”应用（Android 4.4.2，arm-emu）中选择图片，

 I have uri.getPath = /document/image:16 and function getRealPathFromURI returns null.

我该如何为双向操作返回正确的文件路径？

我的代码是：

    @Override
    public void onClick(View v) {
        final File root = new File(Environment.getExternalStorageDirectory() + File.separator + "Photohunt" + File.separator);
        root.mkdirs();
        final String fname = Common.getUniqueImageFilename();
        final File sdImageMainDirectory = new File(root, fname);
        outputFileUri = Uri.fromFile(sdImageMainDirectory);
            // Camera.
            final List<Intent> cameraIntents = new ArrayList<Intent>();
            final Intent captureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
            final PackageManager packageManager = mContext.getPackageManager();
            final List<ResolveInfo> listCam = packageManager.queryIntentActivities(captureIntent, 0);
            for(ResolveInfo res : listCam) {
                final String packageName = res.activityInfo.packageName;
                final Intent intent = new Intent(captureIntent);
                intent.setComponent(new ComponentName(res.activityInfo.packageName, res.activityInfo.name));
                intent.setPackage(packageName);
            intent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
                cameraIntents.add(intent);
            }

            // Filesystem.
            final Intent galleryIntent = new Intent();
            galleryIntent.setType("image/*");
            galleryIntent.setAction(Intent.ACTION_GET_CONTENT);

            // Chooser of filesystem options.
            final Intent chooserIntent = Intent.createChooser(galleryIntent, "Select Source");

            // Add the camera options.
            chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, cameraIntents.toArray(new Parcelable[]{}));

            startActivityForResult(chooserIntent, PICTURE_REQUEST_CODE);
    }

处理活动结果：

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data)
{
    if(resultCode == Activity.RESULT_OK)
    {
        if(requestCode == PICTURE_REQUEST_CODE)
        {
            final boolean isCamera;
            if(data == null)
            {
                isCamera = true;
            }
            else
            {
                final String action = data.getAction();
                if(action == null)
                {
                    isCamera = false;
                }
                else
                {
                    isCamera = action.equals(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
                }
            }

            Uri selectedImageUri;
            if(isCamera)
            {
                selectedImageUri = outputFileUri;
            }
            else
            {
                selectedImageUri = data == null ? null : data.getData();
            }

            Log.variable("uri", selectedImageUri.getPath());
            ConfirmImageFragment fragment = new ConfirmImageFragment(selectedImageUri, mContestId);
            FragmentTransaction transaction = getSherlockActivity().getSupportFragmentManager().beginTransaction();
            transaction.replace(R.id.main_container, fragment);
            transaction.addToBackStack(null);
            transaction.commit();
        }
    }

    super.onActivityResult(requestCode, resultCode, data);
}

将所选文件加载到ImageView中对于两种状态都可以正常工作：

private void loadImage() {
    try {
        Bitmap bitmap = MediaStore.Images.Media.getBitmap(mContext.getContentResolver(), mUri);
        mImage.setImageBitmap(bitmap);
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}