纯C#、.Net生成分享二维码海报

           public string Draw()
          {
              //背景图片，海报背景
              string path = Server.MapPath("/Content/tg.jpg");

              System.Drawing.Image imgSrc = System.Drawing.Image.FromFile(path);

              //处理二维码图片大小 240*240px
              System.Drawing.Image qrCodeImage = ReduceImage("https://api.ooopn.com/qr/api.php?text=https://www.sssam.com&size=360px", 0, 0);

              //处理头像图片大小 100*100px，我这里没放头像，所以注释掉，用到的话放开注释自己测。同时下方也放开
              //Image titleImage = ReduceImage(user.headimgurl, 100, 100);

              using (Graphics g = Graphics.FromImage(imgSrc))
              {
                  //画专属推广二维码
                  g.DrawImage(qrCodeImage, new Rectangle(imgSrc.Width - qrCodeImage.Width -450,//-450这个数，越小越靠左，可以调整二维码在背景图的位置
                  imgSrc.Height - qrCodeImage.Height-650 ,//同理-650越小越靠上
                  qrCodeImage.Width,
                  qrCodeImage.Height),
                  0, 0, qrCodeImage.Width, qrCodeImage.Height, GraphicsUnit.Pixel);

                  //画头像
                  //g.DrawImage(titleImage, 8, 8, titleImage.Width, titleImage.Height);

                  Font font = new Font("宋体", 30, FontStyle.Bold);

                  g.DrawString("这里输入文字", font, new SolidBrush(Color.Red), 500, 800);
              }
              string newpath = Server.MapPath(@"/Content/newtg_" + Guid.NewGuid().ToString() + ".jpg");
              imgSrc.Save(newpath, System.Drawing.Imaging.ImageFormat.Jpeg);
              return newpath;
          }

　　　　　　//获取图片并处理成指定只存返回，宽高填写0，直接返回原尺寸
　　　　　　public Image ReduceImage(string url, int toWidth, int toHeight)
          {
              //这里网络方式获取图片二维码，本地读取请自己写
              WebRequest request = WebRequest.Create(url);
              WebResponse response = request.GetResponse();
              Stream responseStream = response.GetResponseStream();

              Image originalImage = Image.FromStream(responseStream);
              if (toWidth <= 0 && toHeight <= 0)
              {
                  return originalImage;//这里直接返回
              }
              else if (toWidth > 0 && toHeight > 0)
              {
                  if (originalImage.Width < toWidth && originalImage.Height < toHeight)
                      return originalImage;
              }
              else if (toWidth <= 0 && toHeight > 0)
              {
                  if (originalImage.Height < toHeight)
                      return originalImage;
                  toWidth = originalImage.Width * toHeight / originalImage.Height;
              }
              else if (toHeight <= 0 && toWidth > 0)
              {
                  if (originalImage.Width < toWidth)
                      return originalImage;
                  toHeight = originalImage.Height * toWidth / originalImage.Width;
              }
              Image toBitmap = new Bitmap(toWidth, toHeight);
              using (Graphics g = Graphics.FromImage(toBitmap))
              {
                  g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
                  g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                  g.Clear(Color.Transparent);
                  g.DrawImage(originalImage,
                              new Rectangle(0, 0, toWidth, toHeight),
                              new Rectangle(0, 0, originalImage.Width, originalImage.Height),
                              GraphicsUnit.Pixel);
                  originalImage.Dispose();
                  return toBitmap;
              }
          }

　　这里是生成分享海报，下一篇将完成---->将海报分享至微信及朋友圈。