文件上传（记）

public static void UploadImage(System.Web.HttpPostedFile postedFile, int templateWidth, int templateHeight, string fileSaveUrl)
        {
            //从文件获取原始图片，并使用流中嵌入的颜色管理信息 
            using (System.Drawing.Image initImage = System.Drawing.Image.FromStream(postedFile.InputStream, true))
            {
                //原图宽高均小于模版，不作处理，直接保存 
                if (initImage.Width <= templateWidth && initImage.Height <= templateHeight)
                {
                    //initImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);
                   
                }
                else
                {
                    //模版的宽高比例 
                    double templateRate = double.Parse(templateWidth.ToString()) / templateHeight;
                    //原图片的宽高比例 
                    double initRate = double.Parse(initImage.Width.ToString()) / initImage.Height;

 

                    //原图与模版比例相等，直接缩放 
                    if (templateRate == initRate)
                    {
                        //按模版大小生成最终图片 
                        System.Drawing.Image templateImage = new System.Drawing.Bitmap(templateWidth, templateHeight);
                        System.Drawing.Graphics templateG = System.Drawing.Graphics.FromImage(templateImage);
                        templateG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
                        templateG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                        templateG.Clear(Color.White);
                        templateG.DrawImage(initImage, new System.Drawing.Rectangle(0, 0, templateWidth, templateHeight), new System.Drawing.Rectangle(0, 0, initImage.Width, initImage.Height), System.Drawing.GraphicsUnit.Pixel);
                        templateImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);
                    }
                    //原图与模版比例不等，裁剪后缩放 
                    else
                    {
                        //裁剪对象 
                        System.Drawing.Image pickedImage = null;
                        System.Drawing.Graphics pickedG = null;

                        //定位 
                        Rectangle fromR = new Rectangle(0, 0, 0, 0);//原图裁剪定位 
                        Rectangle toR = new Rectangle(0, 0, 0, 0);//目标定位 

                        //宽为标准进行裁剪 
                        if (templateRate > initRate)
                        {
                            //裁剪对象实例化 
                            pickedImage = new System.Drawing.Bitmap(initImage.Width, int.Parse(Math.Floor(initImage.Width / templateRate).ToString()));
                            pickedG = System.Drawing.Graphics.FromImage(pickedImage);

                            //裁剪源定位 
                            fromR.X = 0;
                            fromR.Y = int.Parse(Math.Floor((initImage.Height - initImage.Width / templateRate) / 2).ToString());
                            fromR.Width = initImage.Width;
                            fromR.Height = int.Parse(Math.Floor(initImage.Width / templateRate).ToString());

                            //裁剪目标定位 
                            toR.X = 0;
                            toR.Y = 0;
                            toR.Width = initImage.Width;
                            toR.Height = int.Parse(Math.Floor(initImage.Width / templateRate).ToString());
                        }
                        //高为标准进行裁剪 
                        else
                        {
                            pickedImage = new System.Drawing.Bitmap(int.Parse(Math.Floor(initImage.Height * templateRate).ToString()), initImage.Height);
                            pickedG = System.Drawing.Graphics.FromImage(pickedImage);

                            fromR.X = int.Parse(Math.Floor((initImage.Width - initImage.Height * templateRate) / 2).ToString());
                            fromR.Y = 0;
                            fromR.Width = int.Parse(Math.Floor(initImage.Height * templateRate).ToString());
                            fromR.Height = initImage.Height;

                            toR.X = 0;
                            toR.Y = 0;
                            toR.Width = int.Parse(Math.Floor(initImage.Height * templateRate).ToString());
                            toR.Height = initImage.Height;
                        }

                        //设置质量 
                        pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                        pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

                        //裁剪 
                        pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel);

                        //按模版大小生成最终图片 

                        using (System.Drawing.Image templateImage = new System.Drawing.Bitmap(templateWidth, templateHeight))
                        {
                            System.Drawing.Graphics templateG = System.Drawing.Graphics.FromImage(templateImage);
                            templateG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
                            templateG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                            templateG.Clear(Color.White);
                            templateG.DrawImage(pickedImage, new System.Drawing.Rectangle(0, 0, templateWidth, templateHeight), new System.Drawing.Rectangle(0, 0, pickedImage.Width, pickedImage.Height), System.Drawing.GraphicsUnit.Pixel);

                            templateImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg);

                            //释放资源 
                            templateG.Dispose();
                            templateImage.Dispose();

                            pickedG.Dispose();
                            pickedImage.Dispose();
                        }
                    }
                }
                // 释放资源 
                initImage.Dispose();
            }
        }