按原图比例缩放，居中，多余的裁剪，图像之间留间距

/// <summary>
        /// 按原图比例缩放，居中，多余的裁剪，图像之间留间距
        /// </summary>
        /// <param name="sourceFile"></param>
        /// <param name="destFilePath"></param>
        /// <param name="destWidth"></param>
        /// <param name="destHeight"></param>
        public static void ImageCutZoomSize(System.IO.Stream sourceFile, string destFilePath, int destWidth, int destHeight)
        {
            try
            {
                //源图片
                System.Drawing.Image bmp = System.Drawing.Bitmap.FromStream(sourceFile);
                System.Drawing.Imaging.ImageFormat thisFormat = bmp.RawFormat;

                int w = bmp.Width;
                int h = bmp.Height;

                //int x = 0;
                //int y = 300;

                //图像之间留2个像素间距 y += 1;
                //destHeight -= 2;
                //计算图片宽高比
                double ratio_img = (double)w / h;
                double ratio_blk = (double)destWidth / destHeight; //0.44270833

                int img_x = 0, img_y = 1;
                int cut_w = w, cut_h = h;

                if (ratio_img >= ratio_blk)
                {
                    //宽图片，求img_x
                    cut_w = (int)Math.Round(h * ratio_blk);
                    img_x += (w - cut_w) / 2;
                }
                else
                {
                    //高图片，求img_y
                    cut_h = (int)Math.Round(w / ratio_blk);
                    img_y += (h - cut_h) / 2;
                }

                //裁剪后新的值
               
                //System.Windows.Forms.MessageBox.Show("img_x" + img_x + "," +
                //    "img_y" + img_y + "," +
                //    "cut_w" + cut_w + "," +
                //    "cut_h" + cut_h + ",裁剪后新的值");
                
                if (img_x + cut_w > w)
                {
                    cut_w = w - img_x;
                }

                if (img_y + cut_h > h)
                {
                    cut_h = h - img_y;
                }

                //裁剪
                Image bmpOut = new Bitmap(cut_w, cut_h, PixelFormat.Format24bppRgb);

                Graphics gcut = Graphics.FromImage(bmpOut);
                gcut.Clear(Color.Black);
                gcut.DrawImage(bmp, new Rectangle(0, 0, cut_w, cut_h), new Rectangle(img_x, img_y, cut_w, cut_h), GraphicsUnit.Pixel);
                gcut.Dispose();
                //bmpOut.Save(@"E:\19gcut.jpg");
                //裁剪 完成 
                ////缩放
                //目标图片
                Image destImg = new Bitmap(destWidth, destHeight);
                Graphics gresize = Graphics.FromImage(destImg);
                gresize.Clear(Color.Black);
                // 插值算法的质量 设置画布的描绘质量
                gresize.CompositingQuality = CompositingQuality.HighQuality;
                gresize.SmoothingMode = SmoothingMode.HighQuality;
                gresize.InterpolationMode = InterpolationMode.HighQualityBicubic;

                gresize.DrawImage(bmpOut, new Rectangle(0, 0, destWidth, destHeight), new Rectangle(0, 0, bmpOut.Width, bmpOut.Height), GraphicsUnit.Pixel);
                gresize.Dispose();
                //destImg.Save(@"E:\19resizet.jpg");//ok
                ////缩放完成


                // 以下代码为保存图片时，设置压缩质量
                EncoderParameters encoderParams = new EncoderParameters();
                long[] quality = new long[1];
                quality[0] = 100;

                EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
                encoderParams.Param[0] = encoderParam;


                //获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象。
                ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();
                ImageCodecInfo jpegICI = null;
                for (int a = 0; a < arrayICI.Length; a++)
                {
                    if (arrayICI[a].FormatDescription.Equals("JPEG"))
                    {
                        jpegICI = arrayICI[a];//设置JPEG编码
                        break;
                    }
                }

                if (jpegICI != null)
                {
                    destImg.Save(destFilePath, jpegICI, encoderParams);
                }
                else
                {
                    destImg.Save(destFilePath, thisFormat);
                }
                /*****************/


                bmp.Dispose();
                bmpOut.Dispose();
                destImg.Dispose();
                if(sourceFile.ReadByte()<0)
                    sourceFile.Close();

            }
            catch (Exception ex)
            {
                throw ex;
            }
            //finally
            //{
            //    bmp.Dispose();
            //    bitmap.Dispose();
            //}
        }
        


     
        /// <summary>
        /// 返回本机的IPAddress[]，一般第一个就是本机网卡的IP
        /// </summary>
        public static System.Net.IPAddress[] LocalHostIPAddress
        {
            get
            {
                //Dns.GetHostByName(Dns.GetHostName()).;
                return System.Net.Dns.GetHostByName(System.Net.Dns.GetHostName()).AddressList;
            }
        }
        

     
       
      
        /// <summary>
        /// 判断是否合法IP   /// </summary>
        /// <param name="strIP"></param>
        /// <returns></returns>
        public static bool ValidateIPAddress(string strIP)
        {
            //if (null == strIP || "" == strIP.Trim() || Convert.IsDBNull(strIP))
            if (string.IsNullOrEmpty(strIP.Trim()) || Convert.IsDBNull(strIP))
            { return false; }

            return System.Text.RegularExpressions.Regex.IsMatch(strIP, @"^((\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.){3}(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])$");
        }

        public static DirectoryInfo MaxDirRoot()
        {
            List<DriveInfo> dirlist = new List<DriveInfo>();

            foreach (DriveInfo dri in DriveInfo.GetDrives())
            {
                if (dri.DriveType == DriveType.Fixed)//确定固定硬盘
                {
                    dirlist.Add(dri);
                }
            }
            if (dirlist.Count > 1)
            {
                DriveInfo drinfo = null;
                for (int d = 1; d < dirlist.Count; d++)
                {
                    if (dirlist[d - 1].TotalFreeSpace < dirlist[d].TotalFreeSpace)
                    {
                        drinfo = dirlist[0];
                        dirlist[0] = dirlist[d + 1];
                        dirlist[d] = drinfo;
                    }
                }
                //MessageBox.Show(drinfo.Name + drinfo.TotalFreeSpace.ToString());
                DirectoryInfo dirinfo = drinfo.RootDirectory.CreateSubdirectory("mediadatas");
                dirinfo.Attributes = FileAttributes.Directory;
                dirinfo.Attributes = FileAttributes.Hidden;
                return dirinfo;
            }
            else
            {

                DirectoryInfo dirinfo = dirlist[0].RootDirectory;
                return dirinfo;
            }
        }

    }
}