图片 加文字水印或者图片水印

查msdn，

截图如下：

代码如下：

 if (this.FileUpload1.HasFile)
        {
            string filename = this.FileUpload1.FileName;//获得文件名
             string fileExtension = Path.GetExtension(filename).ToUpper();//获得扩展名
             string filenameforSave = DateTime.Now.ToFileTimeUtc().ToString() ;
            double size = this.FileUpload1.PostedFile.ContentLength/1024;
            string sFileMap = Server.MapPath(@"img\") + filenameforSave;
            if (size < 200)
            {
                if (fileExtension == ".JPG" || fileExtension == ".BMP" || fileExtension == ".GIF")
                {
                    this.FileUpload1.SaveAs(sFileMap+fileExtension);
                  
                    System.Drawing.Image image = System.Drawing.Image.FromFile(sFileMap+fileExtension);
                    #region 文字水印
                    //Graphics graphics = Graphics.FromImage(image);
                    //graphics.DrawImage(image, 0, 0, image.Width, image.Height);
                    //Font f = new Font("Verdana", 32);
                    //Brush b = new SolidBrush(Color.Red);
                    //graphics.DrawString(this.TextBox1.Text.Trim(), f, b, 10, 10);
                    //graphics.Flush();
                    //graphics.Dispose();
                    //image.Save(Server.MapPath(@"img\") + filenameforSave+"_new" + fileExtension);
                    //image.Dispose();
                     #endregion
                    #region  图片水印
                    //System.Drawing.Image copyImage = System.Drawing.Image.FromFile(Server.MapPath(@"img\") + "logo.gif");
                    //Graphics graphics = Graphics.FromImage(image);
                    //graphics.DrawImage(copyImage, new Rectangle(image.Width - copyImage.Width, image.Height - copyImage.Height, copyImage.Width, copyImage.Height), 0, 0, copyImage.Width, copyImage.Height, GraphicsUnit.Pixel);
                    //graphics.Flush();
                    //image.Save(sFileMap + "11_new" + fileExtension);
                    //image.Dispose();
                     #endregion
                }
                else
                {
                    Page.RegisterStartupScript("", "<script language=javascript>alert('上传的文件格式错误!');location='javascript:history.go(-1)'</script>");
                    return;
                }
            }
            else
            {
                Page.RegisterStartupScript("", "<script language=javascript>alert('上传的文件不能大于200KB!');location='javascript:history.go(-1)'</script>");
                return;
            }
        }
        else
        {
            Page.RegisterStartupScript("", "<script language=javascript>alert('请选择上传的文件!');location='javascript:history.go(-1)'</script>");
            return;
        }
    }