使用新创建的位图更新android图库

Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);

Canvas canvas = new Canvas(bitmap);
// 在这里绘制内容

File file = new File(Environment.getExternalStorageDirectory(), "image.png");
FileOutputStream out = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
out.flush();
out.close();

ContentValues values = new ContentValues();
values.put(MediaStore.Images.Media.MIME_TYPE, "image/png");
values.put(MediaStore.Images.Media.DATE_ADDED, System.currentTimeMillis() / 1000);
values.put(MediaStore.Images.Media.DATA, file.getAbsolutePath());
ContentResolver contentResolver = getContentResolver();
Uri url = contentResolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);

Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
mediaScanIntent.setData(Uri.fromFile(file));
sendBroadcast(mediaScanIntent);