图片上传 生成缩略图

    // ＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
        public void MakeImage(string picPath, string Filename, int width, int height, string heads, string mode)
        {
            Image originalImage = Image.FromFile(picPath + "\\" + Filename);

            int towidth = width;
            int toheight = height;

            int x = 0;
            int y = 0;
            int ow = originalImage.Width;
            int oh = originalImage.Height;

            switch (mode)
            {
                case "HW"://指定高宽缩放（可能变形）               
                    break;
                case "W"://指定宽，高按比例                   
                    toheight = originalImage.Height * width / originalImage.Width;
                    break;
                case "H"://指定高，宽按比例
                    towidth = originalImage.Width * height / originalImage.Height;
                    break;
                case "Cut"://指定高宽裁减（不变形）               
                    if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
                    {
                        oh = originalImage.Height;
                        ow = originalImage.Height * towidth / toheight;
                        y = 0;
                        x = (originalImage.Width - ow) / 2;
                    }
                    else
                    {
                        ow = originalImage.Width;
                        oh = originalImage.Width * height / towidth;
                        x = 0;
                        y = (originalImage.Height - oh) / 2;
                    }
                    break;
                default:
                    break;
            }

            //新建一个bmp图片
            Image bitmap = new System.Drawing.Bitmap(towidth, toheight);

            //新建一个画板
            Graphics g = System.Drawing.Graphics.FromImage(bitmap);

            //设置高质量插值法
            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

            //设置高质量,低速度呈现平滑程度
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

            //清空画布并以透明背景色填充
            g.Clear(Color.Transparent);

            //在指定位置并且按指定大小绘制原图片的指定部分
            g.DrawImage(originalImage, new Rectangle(0, 0, towidth, toheight),
                new Rectangle(x, y, ow, oh),
                GraphicsUnit.Pixel);

            try
            {
                //以jpg格式保存缩略图
                bitmap.Save(picPath + "\\" + heads + Filename, System.Drawing.Imaging.ImageFormat.Jpeg);
            }
            catch (System.Exception e)
            {
                throw e;
            }
            finally
            {
                originalImage.Dispose();
                bitmap.Dispose();
                g.Dispose();
            }
        }

        public string HtmlDecode(string tem)
        {
            string ReValue = "";
            ReValue = tem.Replace("  ", "&nbsp;&nbsp;&nbsp;&nbsp;").Replace("\n", "<br />");
            return ReValue;
        }

        //显示指定长度字符串
        public string LeftStr(string strToSub, int length)
        {
            Regex regex = new Regex("[\u4e00-\u9fa5]|[A-Z]", RegexOptions.Compiled);
            char[] strChar = strToSub.ToCharArray();
            StringBuilder sb = new StringBuilder();
            int nLength = 0;
            for (int i = 0; i < strChar.Length; i++)
            {
                if (regex.IsMatch((strChar[i]).ToString()))
                {
                    nLength += 2;
                }
                else
                {
                    nLength = nLength + 1;
                }

                if (nLength <= length)
                {
                    sb.Append(strChar[i]);
                }
                else
                {
                    break;
                }
            }
            if (sb.ToString() != strToSub)
            {
                sb.Append(".");
            }
            return sb.ToString();
        }