在过去的Android Q中，MediaStore.Images.Media.DATA将不再可用，有什么办法吗?这个字段在Android Q中被贬低了:

此常量在API级别29中已弃用。 应用程序可能没有直接访问此路径的文件系统权限。不要试图直接打开这个路径，应用程序应该使用ContentResolver#openFileDescriptor(Uri，字符串)来获得访问权限。

https://developer.android.com/reference/android/provider/MediaStore.MediaColumns.html#DATA

——编辑

据我所知，对于过去的Android Q，唯一的方法是依赖RELATIVE_PATH

该媒体项在存储设备中的相对路径。例如，存储在/storage/0000-0000/DCIM/Vacation/IMG1024.JPG的项的路径为DCIM/Vacation/。

https://developer.android.com/reference/android/provider/MediaStore.MediaColumns.html#RELATIVE_PATH

由于managedQuery已弃用，您可以尝试:

CursorLoader cursorLoader = new CursorLoader(context, uri, proj, null, null, null);
Cursor cursor = cursorLoader.loadInBackground();

不要尝试在文件系统中查找uri，那样在数据库中查找东西会很慢。

你可以通过给工厂一个输入流来从uri中获得位图，就像给工厂一个文件一样:

InputStream is = getContentResolver().openInputStream(uri);
Bitmap bitmap = BitmapFactory.decodeStream(is);
is.close();

下面API 19使用这段代码从URI中获取文件路径:

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

我是这样做的:

    Uri queryUri = MediaStore.Files.getContentUri("external");
    String columnData = MediaStore.Files.FileColumns.DATA;
    String columnSize = MediaStore.Files.FileColumns.SIZE;

    String[] projectionData = {MediaStore.Files.FileColumns.DATA};


    String name = null;
    String size = null;

    Cursor cursor = getContentResolver().query(contentURI, null, null, null, null);
    if ((cursor != null)&&(cursor.getCount()>0)) {
        int nameIndex = cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
        int sizeIndex = cursor.getColumnIndex(OpenableColumns.SIZE);

        cursor.moveToFirst();

        name = cursor.getString(nameIndex);
        size = cursor.getString(sizeIndex);

        cursor.close();
    }

    if ((name!=null)&&(size!=null)){
        String selectionNS = columnData + " LIKE '%" + name + "' AND " +columnSize + "='" + size +"'";

        Cursor cursorLike = getContentResolver().query(queryUri, projectionData, selectionNS, null, null);

        if ((cursorLike != null)&&(cursorLike.getCount()>0)) {
            cursorLike.moveToFirst();
            int indexData = cursorLike.getColumnIndex(columnData);
            if (cursorLike.getString(indexData) != null) {
                result = cursorLike.getString(indexData);
            }
            cursorLike.close();
        }
    }

    return result;

现有的很好的答案，其中一些是我自己想出来的:

我必须从URI中获取路径，并从路径中获取URI，谷歌很难区分，因此对于任何有相同问题的人(例如，从MediaStore中获取视频的缩略图，其物理位置您已经拥有)。前:

/**
 * Gets the corresponding path to a file from the given content:// URI
 * @param selectedVideoUri The content:// URI to find the file path from
 * @param contentResolver The content resolver to use to perform the query.
 * @return the file path as a string
 */
private String getFilePathFromContentUri(Uri selectedVideoUri,
        ContentResolver contentResolver) {
    String filePath;
    String[] filePathColumn = {MediaColumns.DATA};

    Cursor cursor = contentResolver.query(selectedVideoUri, filePathColumn, null, null, null);
    cursor.moveToFirst();

    int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
    filePath = cursor.getString(columnIndex);
    cursor.close();
    return filePath;
}

后者(我用于视频，但也可以用于音频或文件或其他类型的存储内容，通过替换MediaStore。音频(等)MediaStore.Video):

/**
 * Gets the MediaStore video ID of a given file on external storage
 * @param filePath The path (on external storage) of the file to resolve the ID of
 * @param contentResolver The content resolver to use to perform the query.
 * @return the video ID as a long
 */
private long getVideoIdFromFilePath(String filePath,
        ContentResolver contentResolver) {


    long videoId;
    Log.d(TAG,"Loading file " + filePath);

            // This returns us content://media/external/videos/media (or something like that)
            // I pass in "external" because that's the MediaStore's name for the external
            // storage on my device (the other possibility is "internal")
    Uri videosUri = MediaStore.Video.Media.getContentUri("external");

    Log.d(TAG,"videosUri = " + videosUri.toString());

    String[] projection = {MediaStore.Video.VideoColumns._ID};

    // TODO This will break if we have no matching item in the MediaStore.
    Cursor cursor = contentResolver.query(videosUri, projection, MediaStore.Video.VideoColumns.DATA + " LIKE ?", new String[] { filePath }, null);
    cursor.moveToFirst();

    int columnIndex = cursor.getColumnIndex(projection[0]);
    videoId = cursor.getLong(columnIndex);

    Log.d(TAG,"Video ID is " + videoId);
    cursor.close();
    return videoId;
}

基本上，MediaStore的DATA列(或正在查询的任何子部分)存储文件路径，因此您可以使用已知的内容查找DATA字段，也可以使用该字段查找所需的任何其他内容。

然后，我进一步使用上述方案来确定如何处理我的数据:

 private boolean  getSelectedVideo(Intent imageReturnedIntent, boolean fromData) {

    Uri selectedVideoUri;

    //Selected image returned from another activity
            // A parameter I pass myself to know whether or not I'm being "shared via" or
            // whether I'm working internally to my app (fromData = working internally)
    if(fromData){
        selectedVideoUri = imageReturnedIntent.getData();
    } else {
        //Selected image returned from SEND intent 
                    // which I register to receive in my manifest
                    // (so people can "share via" my app)
        selectedVideoUri = (Uri)getIntent().getExtras().get(Intent.EXTRA_STREAM);
    }

    Log.d(TAG,"SelectedVideoUri = " + selectedVideoUri);

    String filePath;

    String scheme = selectedVideoUri.getScheme(); 
    ContentResolver contentResolver = getContentResolver();
    long videoId;

    // If we are sent file://something or content://org.openintents.filemanager/mimetype/something...
    if(scheme.equals("file") || (scheme.equals("content") && selectedVideoUri.getEncodedAuthority().equals("org.openintents.filemanager"))){

        // Get the path
        filePath = selectedVideoUri.getPath();

        // Trim the path if necessary
        // openintents filemanager returns content://org.openintents.filemanager/mimetype//mnt/sdcard/xxxx.mp4
        if(filePath.startsWith("/mimetype/")){
            String trimmedFilePath = filePath.substring("/mimetype/".length());
            filePath = trimmedFilePath.substring(trimmedFilePath.indexOf("/"));
        }

        // Get the video ID from the path
        videoId = getVideoIdFromFilePath(filePath, contentResolver);

    } else if(scheme.equals("content")){

        // If we are given another content:// URI, look it up in the media provider
        videoId = Long.valueOf(selectedVideoUri.getLastPathSegment());
        filePath = getFilePathFromContentUri(selectedVideoUri, contentResolver);

    } else {
        Log.d(TAG,"Failed to load URI " + selectedVideoUri.toString());
        return false;
    }

     return true;
 }