// 注销对象方法API
[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;
}