ASP.NET 按规定尺寸缩放图片

来源：互联网发布：linux服务器运维手册编辑：程序博客网时间：2024/05/13 03:35
 public string ImgFileUp(HttpPostedFile HPF, string saveDir)    {            string returnStr1 = "";        string Extension = new FileInfo(HPF.FileName).Extension;        #region  保存原始文件        //清除多余字符串        saveDir = saveDir.TrimEnd('/').TrimStart('/');        //获取上传日期        string time = string.Concat("/", DateTime.Now.ToString("yyyyMMdd"));        //判读上传文件夹是否存在        bool existDir = Directory.Exists(Server.MapPath(string.Concat("~/", saveDir, time)));        //不存在文件夹,自动创建        if (!existDir)        {            //创建文件夹            Directory.CreateDirectory(Server.MapPath(string.Concat("~/", saveDir, time)));        }        //上传的最初文件名+后缀        string dbImageName = "";        if (n == false)        {            dbImageName = System.IO.Path.GetFileName(HPF.FileName);        }        else        {            dbImageName = Guid.NewGuid() + DateTime.Now.ToString("yyyyMMddHHmmssfff") + Extension;        }                //上传的图像保存的物理路径        string originalImagePath = Server.MapPath(string.Concat("~/", saveDir, time, "/", dbImageName));        //保存图片        //HPF.SaveAs(originalImagePath);         //string originalImagePath = Server.MapPath("/" + saveDir + "/" + time + "/" + dbImageName);        //生成压缩文件              System.Drawing.Image originalImage = System.Drawing.Image.FromStream(HPF.InputStream);        int maxWidth =900;   //图片宽度最大限制        int maxHeight = 900;  //图片高度最大限制        int imgWidth = originalImage.Width;        int imgHeight = originalImage.Height;        if (imgHeight > maxHeight || imgWidth>maxWidth)  //如果宽度超或者高度超过进行压缩        {            if (imgWidth > imgHeight)            {                if (imgWidth > maxWidth)  //如果图片宽度超过限制                {                    float toImgWidth = maxWidth;   //图片压缩后的宽度                     float toImgHeight = imgHeight / (float)(imgWidth / toImgWidth); //图片压缩后的高度                     //新建一个bmp图片                    System.Drawing.Image img = new System.Drawing.Bitmap(Convert.ToInt32(toImgWidth), Convert.ToInt32(toImgHeight));                    Graphics g = System.Drawing.Graphics.FromImage(img);//新建画板                     g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;//设置高质量插值法                    g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;//设置高质量,低速度呈现平滑程度                    g.Clear(Color.Transparent);//清空画布                    g.DrawImage(originalImage, new Rectangle(0, 0, Convert.ToInt32(toImgWidth), Convert.ToInt32(toImgHeight)), new System.Drawing.Rectangle(0, 0, imgWidth, imgHeight), GraphicsUnit.Pixel);//绘制原图片                    img.Save(originalImagePath, System.Drawing.Imaging.ImageFormat.Jpeg);                    originalImage.Dispose();                    img.Dispose();                    g.Dispose();                }            }            else            {                if (imgHeight > maxHeight)                {                    float toImgHeight = maxHeight;  //图片压缩后的高度                    float toImgWidth = imgWidth / (float)(imgHeight / toImgHeight); //图片压缩后的宽度                    //新建一个bmp图片                    System.Drawing.Image img = new System.Drawing.Bitmap(Convert.ToInt32(toImgWidth), Convert.ToInt32(toImgHeight));                    Graphics g = System.Drawing.Graphics.FromImage(img);//新建画板                     g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;//设置高质量插值法                    g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;//设置高质量,低速度呈现平滑程度                    g.Clear(Color.Transparent);//清空画布                    g.DrawImage(originalImage, new Rectangle(0, 0, Convert.ToInt32(toImgWidth), Convert.ToInt32(toImgHeight)), new System.Drawing.Rectangle(0, 0, imgWidth, imgHeight), GraphicsUnit.Pixel);//绘制原图片                    img.Save(originalImagePath, System.Drawing.Imaging.ImageFormat.Jpeg);                    originalImage.Dispose();                    img.Dispose();                    g.Dispose();                }            }        }        else        {            HPF.SaveAs(originalImagePath);         }        returnStr1 = time + "/" + dbImageName;        #endregion        return returnStr1;    }
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