// 回收对象
[DllImport("gdi32")]
static extern int DeleteObject(IntPtr o);

        /**
         * 创建二维码图片
         */
        private ImageSource createQRCode(String content, int width, int height)
        {
            EncodingOptions options;//包含一些编码、大小等的设置
            BarcodeWriter write = null;//用来生成二维码，对应的BarcodeReader用来解码
            options = new QrCodeEncodingOptions
            {
                DisableECI = true,
                CharacterSet = "UTF-8",
                Width = width,
                Height = height,
                Margin = 0
            };
            write = new BarcodeWriter();
            write.Format = BarcodeFormat.QR_CODE;
            write.Options = options;
            Bitmap bitmap = write.Write(content);
            IntPtr ip = bitmap.GetHbitmap();
            BitmapSource bitmapSource = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(
                ip, IntPtr.Zero, Int32Rect.Empty,
                System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());
            DeleteObject(ip);
            return bitmapSource;
        }