保存图片到SD卡，但是Gallery中不能及时显示的有关问题

通过 Intent.ACTION_MEDIA_MOUNTED 进行整个SD卡扫描：

public void sdScan(){     
        sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" 
                    + Environment.getExternalStorageDirectory())));     
    }

 The method is restricted for only system apps from 4.4.

here is the another solution..pass the path of the image you have deleted or added and if the image is deleted pass true or if added then pass false.

   /**
 * Scanning the file in the Gallery database
 * 
 * @param path
 * @param isDelete
 */
private void scanFile(String path, final boolean isDelete) {
    try {
        MediaScannerConnection.scanFile(context, new String[] { path },
                null, new MediaScannerConnection.OnScanCompletedListener() {
                    public void onScanCompleted(String path, Uri uri) {
                        if (isDelete) {
                            if (uri != null) {
                                context.getContentResolver().delete(uri,
                                        null, null);
                            }
                        }
                    }
                });
    } catch (Exception e) {
        e.printStackTrace();
    }

}

 通过 Intent.ACTION_MEDIA_SCANNER_SCAN_FILE 扫描某个文件：

 public void fileScan(String filePath){     
        Uri data = Uri.parse("file://"+filePath);     
        sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, data));     
    }

从mediaStore中删除。

public static void deleteFileFromMediaStore(final ContentResolver contentResolver, final File file) {
    String canonicalPath;
    try {
        canonicalPath = file.getCanonicalPath();
    } catch (IOException e) {
        canonicalPath = file.getAbsolutePath();
    }
    final Uri uri = MediaStore.Files.getContentUri("external");
    final int result = contentResolver.delete(uri,
            MediaStore.Files.FileColumns.DATA + "=?", new String[] {canonicalPath});
    if (result == 0) {
        final String absolutePath = file.getAbsolutePath();
        if (!absolutePath.equals(canonicalPath)) {
            contentResolver.delete(uri,
                    MediaStore.Files.FileColumns.DATA + "=?", new String[]{absolutePath});
        }
    }
}

You can use following technique to update all files present in a single folder:

for (File child : fileFolder.listFiles()) {
    if (child.isFile()) {
        fName = child.getName();
        Log.d("MyTag", "Scanning >> " + child.getName());

    MediaScannerConnection
        .scanFile( MyActivity.this,
        new String[] { "path/of/our/folder" + fName },
        null,  new MediaScannerConnection.OnScanCompletedListener() {
              public void onScanCompleted(
              String path, Uri uri) {
                 Log.i("ExternalStorage",  "Scanned " + path + ":");
                 Log.i("ExternalStorage",  "-> uri=" + uri);
              }
        });
    }
}

删除image并且更新Media

// Set up the projection (we only need the ID)
String[] projection = { MediaStore.Images.Media._ID };

// Match on the file path
String selection = MediaStore.Images.Media.DATA + " = ?";
String[] selectionArgs = new String[] { file.getAbsolutePath() };

// Query for the ID of the media matching the file path
Uri queryUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
ContentResolver contentResolver = getContentResolver();
Cursor c = contentResolver.query(queryUri, projection, selection, selectionArgs, null);
if (c.moveToFirst()) {
    // We found the ID. Deleting the item via the content provider will also remove the file
    long id = c.getLong(c.getColumnIndexOrThrow(MediaStore.Images.Media._ID));
    Uri deleteUri = ContentUris.withAppendedId(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, id);
    contentResolver.delete(deleteUri, null, null);
} else {
    // File not found in media store DB
}
c.close();

手动刷新：

public void getAllUri() {
		Cursor cursor = managedQuery(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, null, null, null,
				MediaStore.Images.Media.DEFAULT_SORT_ORDER);
		cursor.moveToFirst();
		while (!cursor.isAfterLast()) {
			String data = cursor.getString(cursor.getColumnIndex(MediaStore.MediaColumns.DATA));
			File file = new File(data);
			scanFile(file);
			cursor.moveToNext();
		}
		
		Cursor cursor2 = managedQuery(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, null, null, null, MediaStore.Video.Media.DEFAULT_SORT_ORDER);
		cursor2.moveToFirst();
		while(!cursor2.isAfterLast()){
			String path = cursor2.getString(cursor2.getColumnIndex(MediaStore.MediaColumns.DATA));
			File file = new File(path);
			scanFile(file);
			cursor2.moveToNext();
		}
	}

	private void scanFile(File file) {
		MediaScannerConnection.scanFile(this, new String[] { file.toString() }, null, new MediaScannerConnection.OnScanCompletedListener() {
			@Override
			public void onScanCompleted(String path, Uri uri) {
				Log.i("ExternalStorage", "Scanned " + path + ":");
				Log.i("ExternalStorage", "-> uri=" + uri);
			}
		});
	}

转载：http://hxsdit.com/1647

 http://blog.csdn.net/happy08god/article/details/9303715