我在这里尝试了几个答案，我认为我有一个解决方案，每次都可以工作，并且还可以管理权限。

这是基于LEO的巧妙解决方案。这篇文章应该包含所有的代码，你需要使这个工作，它应该工作在任何手机和Android版本;)

为了能够从SD卡中选择文件，你需要在你的清单中这样做:

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

常量:

private static final int PICK_IMAGE = 456; // Whatever number you like
public static final int MY_PERMISSIONS_REQUEST_READ_EXTERNAL = 28528; // Whatever number you like
public static final String FILE_TEMP_NAME = "temp_image"; // Whatever file name you like

检查权限和launchImagePick如果可能的话

if (ContextCompat.checkSelfPermission(getThis(),
        Manifest.permission.READ_EXTERNAL_STORAGE)
        != PackageManager.PERMISSION_GRANTED) {

    ActivityCompat.requestPermissions(getThis(),
            new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
            MY_PERMISSIONS_REQUEST_READ_EXTERNAL);
}
else {
    launchImagePick();
}

允许响应

@Override
public void onRequestPermissionsResult(int requestCode,
                                       @NonNull
                                         String permissions[],
                                       @NonNull
                                         int[] grantResults) {

    if (manageReadExternalPermissionResponse(this, requestCode, grantResults)) {
        launchImagePick();
    }
}

管理权限响应

public static boolean manageReadExternalPermissionResponse(final Activity activity, int requestCode, int[] grantResults) {

    if (requestCode == MY_PERMISSIONS_REQUEST_READ_EXTERNAL) {

        // If request is cancelled, the result arrays are empty.

        if (grantResults.length > 0
                && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

            // Permission was granted, yay! Do the
            // contacts-related task you need to do.
            return true;

        } else if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_DENIED) {

            boolean showRationale = ActivityCompat.shouldShowRequestPermissionRationale(activity,
                    Manifest.permission.READ_EXTERNAL_STORAGE);

            if (!showRationale) {
                // The user also CHECKED "never ask again".
                // You can either enable some fall back,
                // disable features of your app
                // or open another dialog explaining
                // again the permission and directing to
                // the app setting.

            } else {
                // The user did NOT check "never ask again".
                // This is a good place to explain the user
                // why you need the permission and ask if he/she wants
                // to accept it (the rationale).
            }
        } else {
            // Permission denied, boo! Disable the
            // functionality that depends on this permission.
        }
    }
    return false;
}

发射图像选择

private void launchImagePick() {

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

    // see onActivityResult
}

管理图像选择响应

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == PICK_IMAGE) {

        if (resultCode == Activity.RESULT_OK) {
            if (data != null && data.getData() != null) {

                try {
                     InputStream inputStream = getContentResolver().openInputStream(data.getData())
                     if (inputStream != null) {

                        // No special persmission needed to store the file like that
                        FileOutputStream fos = openFileOutput(FILE_TEMP_NAME, Context.MODE_PRIVATE);

                        final int BUFFER_SIZE = 1 << 10 << 3; // 8 KiB buffer
                        byte[] buffer = new byte[BUFFER_SIZE];
                        int bytesRead = -1;
                        while ((bytesRead = inputStream.read(buffer)) > -1) {
                            fos.write(buffer, 0, bytesRead);
                        }
                        inputStream.close();
                        fos.close();

                        File tempImageFile = new File(getFilesDir()+"/"+FILE_TEMP_NAME);

                        // Do whatever you want with the File

                        // Delete when not needed anymore
                        deleteFile(FILE_TEMP_NAME);
                    }
                }
                catch (Exception e) {
                    e.printStackTrace();
                }
            } else {
                // Error display
            }
        } else {
            // The user did not select any image
        }
    }
}

这就是所有的人;这在我所有的电话上都适用。

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。

This is what I do: Uri selectedImageURI = data.getData(); imageFile = new File(getRealPathFromURI(selectedImageURI)); private String getRealPathFromURI(Uri contentURI) { Cursor cursor = getContentResolver().query(contentURI, null, null, null, null); if (cursor == null) { // Source is Dropbox or other similar local file path return contentURI.getPath(); } else { cursor.moveToFirst(); int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA); return cursor.getString(idx); } } NOTE: managedQuery() method is deprecated, so I am not using it.

这个答案是来自m3n0R的问题安卓得到真正的路径Uri.getPath()和我声称没有信用。我只是想那些还没有解决这个问题的人可以使用这个。

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。

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.

Just wanted to say that this answer is brilliant and I'm using it for a long time without problems. But some time ago I've stumbled upon a problem that DownloadsProvider returns URIs in format content://com.android.providers.downloads.documents/document/raw%3A%2Fstorage%2Femulated%2F0%2FDownload%2Fdoc.pdf and hence app is crashed with NumberFormatException as it's impossible to parse its uri segments as long. But raw: segment contains direct uri which can be used to retrieve a referenced file. So I've fixed it by replacing isDownloadsDocument(uri) if content with following:

final String id = DocumentsContract.getDocumentId(uri);
if (!TextUtils.isEmpty(id)) {
if (id.startsWith("raw:")) {
    return id.replaceFirst("raw:", "");
}
try {
    final Uri contentUri = ContentUris.withAppendedId(
            Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
    return getDataColumn(context, contentUri, null, null);
} catch (NumberFormatException e) {
    Log.e("FileUtils", "Downloads provider returned unexpected uri " + uri.toString(), e);
    return null;
}
}