C#生成带logo的二维码

带logo的二维码生成分为两步骤：首先根据输入的内容生成二维码图片，然后读取本地的logo图片，通过图片处理生成带logo的二维码。

生成的二维码效果如下：

下面直接贴出二维码生成类   QRCodeHelper.cs  ,直接调用  CreateQRCodeWithLogo 方法，传入相应参数返回bitmap类型的数据，直接将返回的数据绑定到图片控件，如果是web可以先将图片保存到服务器指定地址在获取显示

/// <summary>
/// 生成带logo二维码
/// </summary>
public class QRCodeHelper
{/// <summary>
 /// 创建二维码
 /// </summary>
 /// <param name="content"></param>
 /// <param name="size"></param>
 /// <returns></returns>
 public static Bitmap Create(string content)
 {
  try
  {
   //var options = new QrCodeEncodingOptions
   //{
   // DisableECI = true,
   // CharacterSet = "UTF-8",
   // Width = size,
   // Height = size,
   // Margin = 0,
   // ErrorCorrection = ErrorCorrectionLevel.H
   //};
   //var writer = new BarcodeWriter();
   //writer.Format = BarcodeFormat.QR_CODE;
   //writer.Options = options;
   //var bmp = writer.Write(content);
   //return bmp;
   QRCodeEncoder qRCodeEncoder = new QRCodeEncoder();
   qRCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;//设置二维码编码格式
   qRCodeEncoder.QRCodeScale = 4;//设置编码测量度    
   qRCodeEncoder.QRCodeVersion = 7;//设置编码版本
   qRCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.M;//设置错误校验
   Bitmap image = qRCodeEncoder.Encode(content);
   return image;
  }
  catch (Exception ex)
  {
   return null;
  }
 }
 /// <summary>
 /// 获取本地图片
 /// </summary>
 /// <param name="fileName"></param>
 /// <returns></returns>
 private static Bitmap GetLocalLog(string fileName)
 {
  Bitmap newBmp = new Bitmap(fileName);
  //Bitmap bmp = new Bitmap(newBmp);
  return newBmp;
 }
 /// <summary>
 /// 生成带logo二维码
 /// </summary>
 /// <returns></returns>
 public static Bitmap CreateQRCodeWithLogo(string content, string logopath)
 {
  //生成二维码
  Bitmap qrcode = Create(content);
  //生成logo
  Bitmap logo = GetLocalLog(logopath);
  ImageUtility util = new ImageUtility();
  Bitmap finalImage = util.MergeQrImg(qrcode, logo);
  return finalImage;
 }
}

下面是从网上找的图片处理类   ImageUtility.cs

public class ImageUtility
{
 #region 合并用户QR图片和用户头像
 /// <summary>
 /// 合并用户QR图片和用户头像
 /// </summary>
 /// <param name="qrImg">QR图片</param>
 /// <param name="headerImg">用户头像</param>
 /// <param name="n"></param>
 /// <returns></returns>
 public Bitmap MergeQrImg(Bitmap qrImg, Bitmap headerImg, double n = 0.23)
 {
  int margin = 10;
  float dpix = qrImg.HorizontalResolution;
  float dpiy = qrImg.VerticalResolution;
  var _newWidth = (10 * qrImg.Width - 36 * margin) * 1.0f / 36;
  var _headerImg = ZoomPic(headerImg, _newWidth / headerImg.Width);
  //处理头像
  int newImgWidth = _headerImg.Width + margin;
  Bitmap headerBgImg = new Bitmap(newImgWidth, newImgWidth);
  headerBgImg.MakeTransparent();
  Graphics g = Graphics.FromImage(headerBgImg);
  g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
  g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
  g.Clear(Color.Transparent);
  Pen p = new Pen(new SolidBrush(Color.White));
  Rectangle rect = new Rectangle(0, 0, newImgWidth - 1, newImgWidth - 1);
  using (GraphicsPath path = CreateRoundedRectanglePath(rect, 1))
  {
   g.DrawPath(p, path);
   g.FillPath(new SolidBrush(Color.White), path);
  }
  //画头像
  Bitmap img1 = new Bitmap(_headerImg.Width, _headerImg.Width);
  Graphics g1 = Graphics.FromImage(img1);
  g1.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
  g1.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
  g1.Clear(Color.Transparent);
  Pen p1 = new Pen(new SolidBrush(Color.Gray));
  Rectangle rect1 = new Rectangle(0, 0, _headerImg.Width - 1, _headerImg.Width - 1);
  using (GraphicsPath path1 = CreateRoundedRectanglePath(rect1, 1))
  {
   g1.DrawPath(p1, path1);
   TextureBrush brush = new TextureBrush(_headerImg);
   g1.FillPath(brush, path1);
  }
  g1.Dispose();
  PointF center = new PointF((newImgWidth - _headerImg.Width) / 2, (newImgWidth - _headerImg.Height) / 2);
  g.DrawImage(img1, center.X, center.Y, _headerImg.Width, _headerImg.Height);
  g.Dispose();
  Bitmap backgroudImg = new Bitmap(qrImg.Width, qrImg.Height);
  backgroudImg.MakeTransparent();
  backgroudImg.SetResolution(dpix, dpiy);
  headerBgImg.SetResolution(dpix, dpiy);
  Graphics g2 = Graphics.FromImage(backgroudImg);
  g2.Clear(Color.Transparent);
  g2.DrawImage(qrImg, 0, 0);
  PointF center2 = new PointF((qrImg.Width - headerBgImg.Width) / 2, (qrImg.Height - headerBgImg.Height) / 2);
  g2.DrawImage(headerBgImg, center2);
  g2.Dispose();
  return backgroudImg;
 }
 #endregion
 #region 图形处理
 /// <summary>
 /// 创建圆角矩形
 /// </summary>
 /// <param name="rect">区域</param>
 /// <param name="cornerRadius">圆角角度</param>
 /// <returns></returns>
 private GraphicsPath CreateRoundedRectanglePath(Rectangle rect, int cornerRadius)
 {
  //下午重新整理下，圆角矩形
  GraphicsPath roundedRect = new GraphicsPath();
  roundedRect.AddArc(rect.X, rect.Y, cornerRadius * 2, cornerRadius * 2, 180, 90);
  roundedRect.AddLine(rect.X + cornerRadius, rect.Y, rect.Right - cornerRadius * 2, rect.Y);
  roundedRect.AddArc(rect.X + rect.Width - cornerRadius * 2, rect.Y, cornerRadius * 2, cornerRadius * 2, 270, 90);
  roundedRect.AddLine(rect.Right, rect.Y + cornerRadius * 2, rect.Right, rect.Y + rect.Height - cornerRadius * 2);
  roundedRect.AddArc(rect.X + rect.Width - cornerRadius * 2, rect.Y + rect.Height - cornerRadius * 2, cornerRadius * 2, cornerRadius * 2, 0, 90);
  roundedRect.AddLine(rect.Right - cornerRadius * 2, rect.Bottom, rect.X + cornerRadius * 2, rect.Bottom);
  roundedRect.AddArc(rect.X, rect.Bottom - cornerRadius * 2, cornerRadius * 2, cornerRadius * 2, 90, 90);
  roundedRect.AddLine(rect.X, rect.Bottom - cornerRadius * 2, rect.X, rect.Y + cornerRadius * 2);
  roundedRect.CloseFigure();
  return roundedRect;
 }
 /// <summary>
 /// 图片按比例缩放
 /// </summary>
 private Image ZoomPic(Image initImage, double n)
 {
  //缩略图宽、高计算
  double newWidth = initImage.Width;
  double newHeight = initImage.Height;
  newWidth = n * initImage.Width;
  newHeight = n * initImage.Height;
  //生成新图
  //新建一个bmp图片
  System.Drawing.Image newImage = new System.Drawing.Bitmap((int)newWidth, (int)newHeight);
  //新建一个画板
  System.Drawing.Graphics newG = System.Drawing.Graphics.FromImage(newImage);
  //设置质量
  newG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
  newG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
  //置背景色
  newG.Clear(Color.Transparent);
  //画图
  newG.DrawImage(initImage, new System.Drawing.Rectangle(0, 0, newImage.Width, newImage.Height), new System.Drawing.Rectangle(0, 0, initImage.Width, initImage.Height), System.Drawing.GraphicsUnit.Pixel);
  newG.Dispose();
  return newImage;
 }
 /// <summary>
 /// 创建缩略图
 /// </summary>
 /// <param name="b"></param>
 /// <param name="destHeight"></param>
 /// <param name="destWidth"></param>
 /// <returns></returns>
 public static Bitmap GetThumbnail(Bitmap b, int destHeight, int destWidth)
 {
  System.Drawing.Image imgSource = b;
  System.Drawing.Imaging.ImageFormat thisFormat = imgSource.RawFormat;
  int sW = 0, sH = 0;
  // 按比例缩放
  int sWidth = imgSource.Width;
  int sHeight = imgSource.Height;
  if (sHeight > destHeight || sWidth > destWidth)
  {
   if ((sWidth * destHeight) > (sHeight * destWidth))
   {
    sW = destWidth;
    sH = (destWidth * sHeight) / sWidth;
   }
   else
   {
    sH = destHeight;
    sW = (sWidth * destHeight) / sHeight;
   }
  }
  else
  {
   sW = sWidth;
   sH = sHeight;
  }
  Bitmap outBmp = new Bitmap(destWidth, destHeight);
  Graphics g = Graphics.FromImage(outBmp);
  g.Clear(Color.Transparent);
  // 设置画布的描绘质量
  g.CompositingQuality = CompositingQuality.HighQuality;
  g.SmoothingMode = SmoothingMode.HighQuality;
  g.InterpolationMode = InterpolationMode.HighQualityBicubic;
  g.DrawImage(imgSource, new Rectangle((destWidth - sW) / 2, (destHeight - sH) / 2, sW, sH), 0, 0, imgSource.Width, imgSource.Height, GraphicsUnit.Pixel);
  g.Dispose();
  // 以下代码为保存图片时，设置压缩质量
  EncoderParameters encoderParams = new EncoderParameters();
  long[] quality = new long[1];
  quality[0] = 100;
  EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
  encoderParams.Param[0] = encoderParam;
  imgSource.Dispose();
  return outBmp;
 }
 #endregion
}

来源：http://www.cnblogs.com/xiangzhong/p/5373822.html