缩略图

        /**//// <summary>
        /// 缩略图
        /// </summary>
        /// <param name="path">图片路径</param>
        /// <returns>bool</returns>
        public bool souImg(string path)
        {
            bool suc = false;
            double smallwidth = 98; //范围宽
            double smallheight = 98; //范围高
            double width; //原图宽
            double height; //原图高
            double newwidth; //缩略图宽
            double newheight; //缩略图高
            double n_scale; //压缩比例
            string newpath; //新文件名;
            newpath = path.Replace(".jpg","x.jpg");
            //从 原图片 创建 Image 对象
            Image image = Image.FromFile(path);
            //获取缩略比例
            width = image.Width;
            height = image.Height;
            if(width > height)
            {
                if (width > smallwidth)
                {
                    n_scale=width/smallwidth;
                    newwidth = smallwidth;
                }
                else 
                {
                    n_scale = 1;

                    newwidth = width;
                }
                newheight = height/n_scale;
        
                if (newheight > smallheight) 
                {
                    n_scale = newheight/smallheight;
                    newheight = smallheight;
                    newwidth = smallwidth/n_scale;
                }
            }
            else
            {
                if (height > smallheight)
                {
                    n_scale=height/smallheight;
                    newheight = smallheight;
                }
                else 
                {
                    n_scale = 1;
                    newheight = height;
                }
                newwidth = width/n_scale;
        
                if (newwidth > smallwidth) 
                {
                    n_scale = newwidth/smallwidth;
                    newwidth = smallwidth;
                    newheight = smallheight/n_scale;
                }
            }
            
            //用指定的大小和格式初始化 Bitmap 类的新实例
            Bitmap bitmap  = new Bitmap(Convert.ToInt32(newwidth),Convert.ToInt32(newheight),PixelFormat.Format32bppArgb);
            //从指定的 Image 对象创建新 Graphics 对象
            Graphics graphics = Graphics.FromImage(bitmap);
            //清除整个绘图面并以透明背景色填充
            graphics.Clear(Color.Transparent);
            //在指定位置并且按指定大小绘制 原图片 对象
            graphics.DrawImage(image, new Rectangle(0, 0, Convert.ToInt32(newwidth), Convert.ToInt32(newheight)));
            image.Dispose(); 
            graphics.Dispose();
            try
            {
                //将此 原图片 以指定格式并用指定的编解码参数保存到指定文件
                bitmap.Save(newpath,ImageFormat.Jpeg);
                suc = true;
            }
            catch
            {
                suc = false;
            }
            
            bitmap.Dispose();

            return suc;
        }