根据Paul Burke的回答，我在解决外部SD卡的URI路径时遇到了许多问题，因为大多数建议的“内置”函数返回的路径都不能解析为文件。

然而，这是我的方法 // TODO处理非主卷。

String resolvedPath = "";
File[] possibleExtSdComposites = context.getExternalFilesDirs(null);
for (File f : possibleExtSdComposites) {
    // Reset final path
    resolvedPath = "";

    // Construct list of folders
    ArrayList<String> extSdSplit = new ArrayList<>(Arrays.asList(f.getPath().split("/")));

    // Look for folder "<your_application_id>"
    int idx = extSdSplit.indexOf(BuildConfig.APPLICATION_ID);

    // ASSUMPTION: Expected to be found at depth 2 (in this case ExtSdCard's root is /storage/0000-0000/) - e.g. /storage/0000-0000/Android/data/<your_application_id>/files
    ArrayList<String> hierarchyList = new ArrayList<>(extSdSplit.subList(0, idx - 2));

    // Construct list containing full possible path to the file
    hierarchyList.add(tail);
    String possibleFilePath = TextUtils.join("/", hierarchyList);

    // If file is found --> success
    if (idx != -1 && new File(possibleFilePath).exists()) {
        resolvedPath = possibleFilePath;
        break;
    }
}

if (!resolvedPath.equals("")) {
    return resolvedPath;
} else {
    return null;
}

注意，它取决于层次结构，可能在每个手机制造商上都是不同的-我没有全部测试过(到目前为止，它在Xperia Z3 API 23和三星Galaxy A3 API 23上运行良好)。

请确认其他地方是否表现不佳

我相信已经发布的回复应该会让人们朝着正确的方向前进。然而，以下是我所做的对我正在更新的遗留代码有意义的事情。遗留代码使用图库中的URI来更改和保存图像。

在4.4之前(和谷歌驱动器)，uri看起来是这样的: 内容:/ /媒体/外部/图片/媒体/ 41

正如问题中所述，它们通常是这样的: 内容:/ / com.android.providers.media.documents /文档/图片:3951

因为我需要保存图像的能力，而不打扰已经存在的代码，我只是从图库中复制URI到应用程序的数据文件夹中。然后从数据文件夹中保存的图像文件中产生一个新的URI。

这个想法是这样的:

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
startActivityForResult(intent), CHOOSE_IMAGE_REQUEST);

public void onActivityResult(int requestCode, int resultCode, Intent data) {

    super.onActivityResult(requestCode, resultCode, data);

    File tempFile = new File(this.getFilesDir().getAbsolutePath(), "temp_image");

    //Copy URI contents into temporary file.
    try {
        tempFile.createNewFile();
        copyAndClose(this.getContentResolver().openInputStream(data.getData()),new FileOutputStream(tempFile));
    }
    catch (IOException e) {
        //Log Error
    }

    //Now fetch the new URI
    Uri newUri = Uri.fromFile(tempFile);

    /* Use new URI object just like you used to */
 }

注意- copyAndClose()只是执行文件I/O，将InputStream复制到FileOutputStream。代码没有被发布。

请尽量避免使用takePersistableUriPermission方法，因为它会为我引发运行时异常。 ／** 从图库中选择。 * /

public void selectFromGallery() {
    if (Build.VERSION.SDK_INT < AppConstants.KITKAT_API_VERSION) {

        Intent intent = new Intent(); 
        intent.setType("image/*");
        intent.setAction(Intent.ACTION_GET_CONTENT);
        ((Activity)mCalledContext).startActivityForResult(intent,AppConstants.GALLERY_INTENT_CALLED);

    } else {

        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.setType("image/*");
        ((Activity)mCalledContext).startActivityForResult(intent, AppConstants.GALLERY_AFTER_KITKAT_INTENT_CALLED);
    }
}

OnActivity的结果处理图像数据:

@Override onActivityResult(int requestCode, int resultCode, Intent data) {

    //gallery intent result handling before kit-kat version
    if(requestCode==AppConstants.GALLERY_INTENT_CALLED 
            && resultCode == RESULT_OK) {

        Uri selectedImage = data.getData();
        String[] filePathColumn = {MediaStore.Images.Media.DATA};
        Cursor cursor = getContentResolver().query(selectedImage,filePathColumn, null, null, null);
        cursor.moveToFirst();
        int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
        String filePath = cursor.getString(columnIndex);
        cursor.close();
        photoFile = new File(filePath);
        mImgCropping.startCropImage(photoFile,AppConstants.REQUEST_IMAGE_CROP);

    }
    //gallery intent result handling after kit-kat version
    else if (requestCode == AppConstants.GALLERY_AFTER_KITKAT_INTENT_CALLED 
            && resultCode == RESULT_OK) {

        Uri selectedImage = data.getData();
        InputStream input = null;
        OutputStream output = null;

        try {
            //converting the input stream into file to crop the 
            //selected image from sd-card.
            input = getApplicationContext().getContentResolver().openInputStream(selectedImage);
            try {
                photoFile = mImgCropping.createImageFile();
            } catch (IOException e) {
                e.printStackTrace();
            }catch(Exception e) {
                e.printStackTrace();
            }
            output = new FileOutputStream(photoFile);

            int read = 0;
            byte[] bytes = new byte[1024];

            while ((read = input.read(bytes)) != -1) {
                try {
                    output.write(bytes, 0, read);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }


    }

这对我来说很有效:

else if(requestCode == GALLERY_ACTIVITY_NEW && resultCode == Activity.RESULT_OK)
{
    Uri uri = data.getData();
    Log.i(TAG, "old uri =  " + uri);
    dumpImageMetaData(uri);

    try {
        ParcelFileDescriptor parcelFileDescriptor =
                getContentResolver().openFileDescriptor(uri, "r");
        FileDescriptor fileDescriptor = parcelFileDescriptor.getFileDescriptor();
        Log.i(TAG, "File descriptor " + fileDescriptor.toString());

        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFileDescriptor(fileDescriptor, null, options);

        options.inSampleSize =
           BitmapHelper.calculateInSampleSize(options,
                                              User.PICTURE_MAX_WIDTH_IN_PIXELS,
                                              User.PICTURE_MAX_HEIGHT_IN_PIXELS);
        options.inJustDecodeBounds = false;

        Bitmap bitmap = BitmapFactory.decodeFileDescriptor(fileDescriptor, null, options);
        imageViewPic.setImageBitmap(bitmap);

        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
        // get byte array here
        byte[] picData = stream.toByteArray();
        ParseFile picFile = new ParseFile(picData);
        user.setProfilePicture(picFile);
    }
    catch(FileNotFoundException exc)
    {
        Log.i(TAG, "File not found: " + exc.toString());
    }
}

有同样的问题，尝试上面的解决方案，但虽然它一般工作，由于某种原因，我得到了一些图像的Uri内容提供者的权限拒绝，尽管我有android.permission。MANAGE_DOCUMENTS权限添加正确。

不管怎样，找到了其他的解决方案，这是迫使打开图库，而不是KITKAT文档视图:

// KITKAT

i = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
    startActivityForResult(i, CHOOSE_IMAGE_REQUEST);

然后加载图片:

Uri selectedImageURI = data.getData();
input = c.getContentResolver().openInputStream(selectedImageURI);
                BitmapFactory.decodeStream(input , null, opts);

EDIT

ACTION_OPEN_DOCUMENT可能需要你持久化权限标志等，通常会导致安全异常…

Other solution is to use the ACTION_GET_CONTENT combined with c.getContentResolver().openInputStream(selectedImageURI) which will work both on pre-KK and KK. Kitkat will use new documents view then and this solution will work with all apps like Photos, Gallery, File Explorer, Dropbox, Google Drive etc...) but remember that when using this solution you have to create image in your onActivityResult() and store it on SD Card for example. Recreating this image from saved uri on next app launch would throw Security Exception on content resolver even when you add permission flags as described in Google API docs (that's what happened when I did some testing)

此外，Android开发者API指南建议:

ACTION_OPEN_DOCUMENT is not intended to be a replacement for ACTION_GET_CONTENT. The one you should use depends on the needs of your app: Use ACTION_GET_CONTENT if you want your app to simply read/import data. With this approach, the app imports a copy of the data, such as an image file. Use ACTION_OPEN_DOCUMENT if you want your app to have long term, persistent access to documents owned by a document provider. An example would be a photo-editing app that lets users edit images stored in a document provider.

正如commonware提到的，你不应该假设，你通过ContentResolver得到的流可以转换成文件。

你真正应该做的是从ContentProvider打开InputStream，然后从中创建一个位图。而且它在4.4和更早的版本上也可以工作，不需要反射。

    //cxt -> current context

    InputStream input;
    Bitmap bmp;
    try {
        input = cxt.getContentResolver().openInputStream(fileUri);
        bmp = BitmapFactory.decodeStream(input);
    } catch (FileNotFoundException e1) {

    }

当然，如果你处理大图片，你应该用适当的inSampleSize: http://developer.android.com/training/displaying-bitmaps/load-bitmap.html加载它们。但那是另一个话题了。