tif文件下载 保存成图片，或图片保存

1.环境：从另一台服务器上抓取tif 文件和图片，保存到本地服务器，其中tif 文件需要拆分成单个图片保存，tif文件是从ftp上得到的。

 遇到的过的问题：

 a.因都是网络图片，考虑的是在线抓取直接将流转化成图片，然后在保存图片.

关键代码：

if (url.StartsWith("http:") )|| url.StartsWith("ftp:"))                    {                        System.Net.WebRequest webreq = System.Net.WebRequest.Create(url);                        System.Net.WebResponse webres = webreq.GetResponse();                        Stream stream = webres.GetResponseStream();                        img = Image.FromStream(stream);                        stream.Close();                    }

问题：文件过大会占有内存过大，导致内存溢出而报错。方案：先下载保存到本地

 b.文件保存到本地后，读取文件使用的是Image.FromFile(path)，此方法会占有文件，导致无法操作文件。

方案：根据下载后的本地地址先转化成数据流且仅只具有读取数据的权限，再创建图片

     关键代码：

 img = null;                        string path = Download(baseUrl, ClaimNumber, url);                        if (!string.IsNullOrEmpty(path))                        {                            FileStream fileStream = new FileStream(path, FileMode.Open, FileAccess.Read);                            int byteLength = (int)fileStream.Length;                            byte[] fileBytes = new byte[byteLength];                            fileStream.Read(fileBytes, 0, byteLength);                            //文件流关閉,文件解除锁定                            fileStream.Close();                            img = Image.FromStream(new MemoryStream(fileBytes));                            //img = Image.FromFile(path);//会占用文件                            System.IO.File.Delete(path);//                        }

 c.tif 文件拆分成图片。

   关键代码：

if (url.EndsWith("tif"))                        {                            Guid guid = (Guid)img.FrameDimensionsList.GetValue(0);                            FrameDimension dimension = new FrameDimension(guid);                            int totalPage = img.GetFrameCount(dimension);                            string total = "共" + totalPage + "页";                            for (int i = 0; i < totalPage; i++)                            {                                ExtClaimFilesInfo info = new ExtClaimFilesInfo();                                info.ClaimNumber = ClaimNumber;                                img.SelectActiveFrame(dimension, i);                                string name = string.Format("{0}_{1}", ClaimNumber, i);                                info.Path1 = UploadFile("claimData", name, dt, img);//原图，缩略图                                info.VisitIndex = 1;                                info.OpTime = DateTime.Now;                                list.Add(info);                            }                        }

 d.图片处理：本地保存缩略图和原图，若原图>500K 再压缩原图(j尽可能的保持原图清晰度)。

      关键代码：

/// <summary>        ///  原图大于500k 压缩图片        /// </summary>        /// <param name="path">原图图片路径</param>        /// <param name="pathnew">压缩后图片路径</param>        public bool OriginalNail(string path,string pathnew)        {            bool suc = false;            if (!string.IsNullOrEmpty(path))            {                try                {                    if (File.Exists(pathnew))                    {                        File.Delete(pathnew);                    }                    FileInfo fi = new FileInfo(path);                    Int64 len = fi.Length;//图片大小                    decimal cnt = CHC.Common.Tools.CalcDivide(len, 1024);                    if (cnt > 500)                    {                        CHC.Common.Picture.MakeThumbnail(path, pathnew, 1200, 120, "W");                        fi.Delete();                    }                    else                    {                        fi.MoveTo(pathnew);                    }                    suc = true;                }                catch (Exception ex)                {                    CHC.DAL.Log.Loger.Error(ex, "原图大于500k 压缩图片异常");                }            }            return suc;         }

2.具体代码：

a.生成缩略图 封装类：Picture

public class Picture    {        /**/        /// <summary>         /// 生成缩略图         /// </summary>         /// <param name="originalImagePath">源图路径（物理路径）</param>         /// <param name="thumbnailPath">缩略图路径（物理路径）</param>         /// <param name="width">缩略图宽度</param>         /// <param name="height">缩略图高度</param>         /// <param name="mode">生成缩略图的方式</param>             public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)        {            Image originalImage = Image.FromFile(originalImagePath);            MakeThumbnail(thumbnailPath, width, height, mode, originalImage);        }        public static void MakeThumbnail(string thumbnailPath, int width, int height, string mode, Stream stream)        {            Image originalImage = new Bitmap(stream);            MakeThumbnail(thumbnailPath, width, height, mode, originalImage);        }        private static void MakeThumbnail(string thumbnailPath, int width, int height, string mode, Image originalImage)        {            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(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);            }            catch (System.Exception e)            {                throw e;            }            finally            {                originalImage.Dispose();                bitmap.Dispose();                g.Dispose();            }        }    }

b.根据路径和图片保存图片 封装方法:UploadFile

    private  string UploadFile(string folder,string name,DateTime? dt, Image img)        {            DateTime dt1 = dt.HasValue ? dt.Value : DateTime.Now;            //string baseUrl = System.Web.HttpContext.Current.Server.MapPath("~/");            string type1 = "original", type2 = "compress"; ;            //原型图路径            string customUrl = string.Format("\\upload\\{0}\\{1}\\{2}", folder, dt1.ToString("yyyyMMdd"), type1);            if (!System.IO.Directory.Exists(baseUrl + customUrl))                System.IO.Directory.CreateDirectory(baseUrl + customUrl);            string path = customUrl + "\\" + name + ".Jpeg";            string path1 = customUrl + "\\" + name+"tmp" + ".Jpeg";            string suoUrl = string.Format("\\upload\\{0}\\{1}\\{2}", folder, dt1.ToString("yyyyMMdd"), type2);            if (!System.IO.Directory.Exists(baseUrl + suoUrl))                System.IO.Directory.CreateDirectory(baseUrl + suoUrl);            string suopath = suoUrl + "\\" + name + ".Jpeg";            //原型图保存            img.Save(baseUrl + path1, System.Drawing.Imaging.ImageFormat.Jpeg);            OriginalNail(baseUrl + path1, baseUrl + path);            //缩略图            CHC.Common.Picture.MakeThumbnail(baseUrl + path, baseUrl + suopath, 120, 120, "Cut");            return suopath.Replace("\\", "/"); ;        }

c.原图大于500k 压缩图片 封装方法:OriginalNail

        /// <summary>        ///  原图大于500k 压缩图片        /// </summary>        /// <param name="path">原图图片路径</param>        /// <param name="pathnew">压缩后图片路径</param>        public bool OriginalNail(string path,string pathnew)        {            bool suc = false;            if (!string.IsNullOrEmpty(path))            {                try                {                    if (File.Exists(pathnew))                    {                        File.Delete(pathnew);                    }                    FileInfo fi = new FileInfo(path);                    Int64 len = fi.Length;//图片大小                    decimal cnt = CHC.Common.Tools.CalcDivide(len, 1024);                    if (cnt > 500)                    {                        CHC.Common.Picture.MakeThumbnail(path, pathnew, 1200, 120, "W");                        fi.Delete();                    }                    else                    {                        fi.MoveTo(pathnew);                    }                    suc = true;                }                catch (Exception ex)                {                    CHC.DAL.Log.Loger.Error(ex, "原图大于500k 压缩图片异常");                }            }            return suc;         }

d.实现ftp下载文件操作 封装方法:Download ，ftp:url中已填入帐号和秘密，则程序中无需配置。

        /// <summary>        /// 实现ftp下载操作        /// </summary>        /// <param name="filePath">保存到本地的文件名</param>        /// <param name="fileName">远程文件名</param>        public string Download(string filePath, string ClaimNumber, string url)        {            FtpWebRequest reqFTP;            //判断临时目录是否存在            if (!System.IO.Directory.Exists(filePath))                System.IO.Directory.CreateDirectory(filePath);            string str = string.Empty;            try            {                str = filePath + "\\" + ClaimNumber + ".tif";                reqFTP = (FtpWebRequest)FtpWebRequest.Create(url);                reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;                reqFTP.UseBinary = true;                //reqFTP.Credentials = new NetworkCredential(ftpUser, ftpPwd);//已放在url中                FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();                Stream ftpStream = response.GetResponseStream();                FileStream outputStream = new FileStream(str, FileMode.Create);                long cl = response.ContentLength;                int bufferSize = 2048;                int readCount;                byte[] buffer = new byte[bufferSize];                readCount = ftpStream.Read(buffer, 0, bufferSize);                while (readCount > 0)                {                    outputStream.Write(buffer, 0, readCount);                    readCount = ftpStream.Read(buffer, 0, bufferSize);                }                ftpStream.Close();                outputStream.Close();                response.Close();            }            catch (Exception ex)            {                str = string.Empty;                CHC.DAL.Log.Loger.Log(ex, string.Format("保存tif文件到本地异常,url:{0},ClaimNumber:{1}", url, ClaimNumber));            }            return str;        }

e.最终调用方法：---tif文件下载 保存成图片，或图片保存

        /// <summary>        /// tif文件下载 保存成图片，或图片保存        /// </summary>        /// <param name="url"></param>        public  List<ExtClaimFilesInfo> Downtif(string url, string ClaimNumber,DateTime? dt)        {            List<ExtClaimFilesInfo> list = new List<ExtClaimFilesInfo>();            try            {                if (!string.IsNullOrEmpty(url))                {                    Image img ;                    if (url.StartsWith("http:") )//|| url.StartsWith("ftp:"))//网络图片,ftp 文件太大，先下载到本地                    {                        System.Net.WebRequest webreq = System.Net.WebRequest.Create(url);                        System.Net.WebResponse webres = webreq.GetResponse();                        Stream stream = webres.GetResponseStream();                        img = Image.FromStream(stream);                        stream.Close();                    }                    else if (url.StartsWith("ftp:"))                    {                        img = null;                        string path = Download(baseUrl, ClaimNumber, url);                        if (!string.IsNullOrEmpty(path))                        {                            FileStream fileStream = new FileStream(path, FileMode.Open, FileAccess.Read);                            int byteLength = (int)fileStream.Length;                            byte[] fileBytes = new byte[byteLength];                            fileStream.Read(fileBytes, 0, byteLength);                            //文件流关閉,文件解除锁定                            fileStream.Close();                            img = Image.FromStream(new MemoryStream(fileBytes));                            //img = Image.FromFile(path);//会占用文件                            System.IO.File.Delete(path);//                        }                    }                    else                    {                        img = Image.FromFile(url);//本地图片                    }                    if (img != null)                    {                        if (url.EndsWith("tif"))                        {                            Guid guid = (Guid)img.FrameDimensionsList.GetValue(0);                            FrameDimension dimension = new FrameDimension(guid);                            int totalPage = img.GetFrameCount(dimension);                            string total = "共" + totalPage + "页";                            for (int i = 0; i < totalPage; i++)                            {                                ExtClaimFilesInfo info = new ExtClaimFilesInfo();                                info.ClaimNumber = ClaimNumber;                                img.SelectActiveFrame(dimension, i);                                string name = string.Format("{0}_{1}", ClaimNumber, i);                                info.Path1 = UploadFile("claimData", name, dt, img);//原图，缩略图                                info.VisitIndex = 1;                                info.OpTime = DateTime.Now;                                list.Add(info);                            }                        }                        else                        {                            ExtClaimFilesInfo info = new ExtClaimFilesInfo();                            info.ClaimNumber = ClaimNumber;                            Random rad = new Random();                            string _newname = DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString() + rad.Next(100, 100000000).ToString();                            string name = string.Format("{0}_{1}", ClaimNumber, _newname);                            info.Path1 = UploadFile("claimData", name, dt, img);//原图，缩略图                            info.VisitIndex = 1;                            info.OpTime = DateTime.Now;                            list.Add(info);                        }                    }                    GC.Collect();                }            }            catch (Exception ex)            {                //throw ex;                CHC.DAL.Log.Loger.Log(ex, string.Format("图片下载异常,url:{0},ClaimNumber:{1}", url, ClaimNumber));            }            return list;        }