.net生成二维码

把链接生成二维码，代码如下：

　　public void ResImg()
    {
        string contents = "http://www.baidu.com";
        Bitmap bmp = GeneratorQrImage(contents);
        MemoryStream ms = new MemoryStream();
        bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
        byte[] arr = new byte[ms.Length];
        ms.Position = 0;
        ms.Read(arr, 0, (int)ms.Length);
        ms.Close();
        Response.Clear();
        Response.ContentType = "image/gif";
        Response.OutputStream.Write(arr, 0, arr.Length);
        Response.End();
    }

/// <summary>
    /// 生成二维码图片
    /// </summary>
    /// <param name="contents">要生成二维码包含的信息</param>
    /// <param name="width">生成的二维码宽度（默认300像素）</param>
    /// <param name="height">生成的二维码高度（默认300像素）</param>
    /// <returns>二维码图片</returns>
    public static Bitmap GeneratorQrImage(string contents, int width = 300, int height = 300)
    {
        if (string.IsNullOrEmpty(contents))
        {
            return null;
        }
        EncodingOptions options = null;
        BarcodeWriter writer = null;
        options = new QrCodeEncodingOptions
        {
            DisableECI = true,
            CharacterSet = "UTF-8",
            Width = width,
            Height = height,
            ErrorCorrection = ErrorCorrectionLevel.H,
        };
        writer = new BarcodeWriter();
        writer.Format = BarcodeFormat.QR_CODE;
        writer.Options = options;

        Bitmap bitmap = writer.Write(contents);
        return bitmap;
    }