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

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();
        }


    }

这个Android库处理奇巧的情况变化(包括旧版本- 2.1+): https://github.com/iPaulPro/aFileChooser

使用String path = FileUtils。getPath(context, uri)将返回的uri转换为可用于所有OS版本的路径字符串。 更多信息请访问:https://stackoverflow.com/a/20559175/860488

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;
}
}

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。

你的问题的答案是你需要有权限。在manifest.xml文件中输入以下代码:

<uses-sdk  android:minSdkVersion="8"   android:targetSdkVersion="18" />
<uses-permission android:name="android.permission.READ_CONTACTS" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
<uses-permission android:name="android.permission.WRITE_OWNER_DATA"></uses-permission>
<uses-permission android:name="android.permission.READ_OWNER_DATA"></uses-permission>`

这对我很管用……