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。

对于那些仍然在Android SDK版本23及以上使用@Paul Burke的代码的人，如果你的项目遇到错误说你缺少EXTERNAL_PERMISSION，并且你非常确定你已经在AndroidManifest.xml文件中添加了user-permission。这是因为在Android API 23或以上和谷歌中，当您在运行时执行访问文件的操作时，有必要再次保证权限。

这意味着:如果你的SDK版本是23或以上，当你选择图片文件并想知道它的URI时，你会被要求读取和写入权限。

下面是我的代码，除了Paul Burke的解决方案。我添加这些代码，我的项目开始工作良好。

private static final int REQUEST_EXTERNAL_STORAGE = 1;
private static final String[] PERMISSINOS_STORAGE = {
    Manifest.permission.READ_EXTERNAL_STORAGE,
    Manifest.permission.WRITE_EXTERNAL_STORAGE
};

public static void verifyStoragePermissions(Activity activity) {
    int permission = ActivityCompat.checkSelfPermission(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE);

    if (permission != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(
                activity,
                PERMISSINOS_STORAGE,
                REQUEST_EXTERNAL_STORAGE
        );
    }
}

在你的activity&fragment请求URI的地方:

private void pickPhotoFromGallery() {

    CompatUtils.verifyStoragePermissions(this);
    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
    intent.setType("image/*");
    // startActivityForResult(intent, REQUEST_PHOTO_LIBRARY);
    startActivityForResult(Intent.createChooser(intent, "选择照片"),
            REQUEST_PHOTO_LIBRARY);
}

在我的例子中，CompatUtils.java是我定义verifyStoragePermissions方法的地方(作为静态类型，所以我可以在其他活动中调用它)。

此外，如果在调用verifyStoragePermissions方法之前先设置一个if状态来查看当前SDK版本是否高于23，这应该更有意义。

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.

@paul burke的答案适用于API级别19及以上的相机和画廊图片，但如果你的Android项目的最低SDK设置为19以下，它就不起作用，上面提到的一些答案并不适用于画廊和相机。好吧，我已经修改了@paul burke的代码，它适用于API级别低于19的代码。下面是代码。

public static String getPath(final Context context, final Uri uri) {

    final boolean isKitKat = Build.VERSION.SDK_INT >=
                             Build.VERSION_CODES.KITKAT;
    Log.i("URI",uri+"");
    String result = uri+"";

    // DocumentProvider
    // if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
    if (isKitKat && (result.contains("media.documents"))) {

        String[] ary = result.split("/");
        int length = ary.length;
        String imgary = ary[length-1];
        final String[] dat = imgary.split("%3A");

        final String docId = dat[1];
        final String type = dat[0];

        Uri contentUri = null;
        if ("image".equals(type)) {
            contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
        }
        else if ("video".equals(type)) {
        }
        else if ("audio".equals(type)) {
        }

        final String selection = "_id=?";
        final String[] selectionArgs = new String[] {
            dat[1]
        };

        return getDataColumn(context, contentUri, selection, selectionArgs);
    }
    else
    if ("content".equalsIgnoreCase(uri.getScheme())) {
        return getDataColumn(context, uri, null, null);
    }
    // File
    else if ("file".equalsIgnoreCase(uri.getScheme())) {
        return uri.getPath();
    }

    return null;
}

public static String getDataColumn(Context context, Uri uri, String selection,
                                   String[] selectionArgs) {
    Cursor cursor = null;
    final String column = "_data";
    final String[] projection = {
            column
    };

    try {
        cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
                null);
        if (cursor != null && cursor.moveToFirst()) {
            final int column_index = cursor.getColumnIndexOrThrow(column);
            return cursor.getString(column_index);
        }
    }
    finally {
        if (cursor != null)
            cursor.close();
    }
    return null;
}

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。