ASP.NET FTP的操作（包括上傳、下載、重命名、刪除、檢查是否存在）

ASP.NET中，有時候會遇到把文件上傳到ftp或者從ftp上下載文件的操作，下文針對這些操作一一展開。

首先，引用命名空間。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

using System.Text;
using System.Net;
using System.Data;
using System.IO;
using System.ComponentModel;

其中，前四個是新建ASP.NET時自動添加的，后五個為手動添加。

然后，在class1類中(假設新添加的類為class1)聲明全局變量，即ftp登陸所需的用戶名和密碼。

 private string ftpUser = "username";   //ftp用戶名
 private string ftpPassword = "12345";   //ftp密碼

接着就是上傳、下載、重命名、刪除和檢查存在的方法了。

1.上傳文件到ftp

上傳的方法代碼如下：

        /// <summary>
        /// 上傳文件
        /// </summary>
        /// <param name="localFile1">本地文件路徑及文件名</param>
        /// <param name="ftpFileName">ftp文件路徑及文件名（文件名可重命名）</param>
        /// <returns>返回bool值</returns>
        public bool fileUpload(string localFile1, string ftpFileName)
        {
            FileInfo localFile = new FileInfo(localFile1);
            bool success = false;
            FtpWebRequest ftpWebRequest = null;
            FileStream localFileStream = null;
            Stream requestStream = null;
            try
            {
                string uri = ftpFileName;
                ftpWebRequest = (FtpWebRequest)FtpWebRequest.Create(new Uri(uri));
                ftpWebRequest.Credentials = new NetworkCredential(ftpUser, ftpPassword);
                ftpWebRequest.UseBinary = true;//指定數據傳輸類型為二進制
                ftpWebRequest.KeepAlive = false;//成功執行一個命令后連接被關閉
                ftpWebRequest.Method = WebRequestMethods.Ftp.UploadFile;// 指定執行什么命令
                ftpWebRequest.ContentLength = localFile.Length;//上傳文件時通知服務器文件的大小 
                int buffLength = 20480;// 緩沖大小設置為20kb
                byte[] buff = new byte[buffLength];
                int contentLen;
                localFileStream = localFile.OpenRead();//打開一個文件流去讀上傳的文件
                requestStream = ftpWebRequest.GetRequestStream();//把上傳的文件寫入流
                contentLen = localFileStream.Read(buff, 0, buffLength);//每次讀文件流的2kb
                while (contentLen != 0)// 流內容沒有結束
                {
                    // 把內容從file stream 寫入 upload stream
                    requestStream.Write(buff, 0, contentLen);
                    contentLen = localFileStream.Read(buff, 0, buffLength);
                }
                success = true;
            }
            catch (Exception)
            {
                success = false;
            }
            finally
            {
                if (requestStream != null)
                {
                    requestStream.Close();
                }
                if (localFileStream != null)
                {
                    localFileStream.Close();
                }
            }
            return success;
        }

調用方法為實例化類對象，然后通過類對象直接調用。

示例：假設該方法包含在class1類中（以下方法均假設包含在class1中），則有：

  class1 ftpClient1 = new class1();  //實例化類FTPClient
  ftpClient1.fileUpload("D:\\456.png", "ftp://192.18.13.11/123.png");    //上傳文件

另一種方法支持斷點續傳的方法如下：

添加命名空間：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

using System.IO;
using System.Net;
using System.Net.Security;
using System.Collections;

using System.Security.Cryptography.X509Certificates;

using System.Web.Configuration;

class1類中的代碼如下：

    public class class1
    {
        private NetworkCredential certificate;
        /// <summary>
        /// 構造函數，提供初始化數據的功能，打開Ftp站點
        /// </summary>
        public class1()
        {
            certificate = new NetworkCredential("administrator", "cnugis202");
        }
        /// <summary>
        /// 創建FTP請求
        /// </summary>
        /// <param name="uri">ftp://myserver/upload.txt</param>
        /// <param name="method">Upload/Download</param>
        /// <returns></returns>
        private FtpWebRequest CreateFtpWebRequest(Uri uri, string method)
        {
            FtpWebRequest ftpClientRequest = (FtpWebRequest)WebRequest.Create(uri);
            ftpClientRequest.Proxy = null;
            ftpClientRequest.Credentials = certificate;
            ftpClientRequest.KeepAlive = true;
            ftpClientRequest.UseBinary = true;
            ftpClientRequest.UsePassive = true;
            ftpClientRequest.Method = method;
            //ftpClientRequest.Timeout = -1;
            return ftpClientRequest;
        }
        //支持斷點續傳
        public bool UploadFile(string sourceFile, Uri destinationPath, int offSet, string ftpMethod)
        {
            try
            {
                FileInfo file = new FileInfo(sourceFile);
                Uri uri = new Uri(destinationPath.AbsoluteUri + "/" + file.Name);
                FtpWebRequest request = CreateFtpWebRequest(uri, ftpMethod);
                request.ContentOffset = offSet;
                Stream requestStream = request.GetRequestStream();//需要獲取文件的流
                FileStream fileStream = new FileStream(sourceFile, FileMode.Open, FileAccess.Read);//創建存儲文件的流
                int sourceLength = (int)fileStream.Length;
                offSet = CopyDataToDestination(fileStream, requestStream, offSet);
                WebResponse response = request.GetResponse();
                response.Close();
                if (offSet != 0)
                {
                    UploadFile(sourceFile, destinationPath, offSet, WebRequestMethods.Ftp.AppendFile);
                }
            }
            catch (Exception ex)
            {
                ex.ToString();
                return false;
            }
            return true;
        }
        private int CopyDataToDestination(Stream sourceStream, Stream destinationStream, int offSet)
        {
            try
            {
                int sourceLength = (int)sourceStream.Length;
                int length = sourceLength - offSet;
                byte[] buffer = new byte[length + offSet];
                int bytesRead = sourceStream.Read(buffer, offSet, length);
                while (bytesRead != 0)
                {
                    destinationStream.Write(buffer, 0, bytesRead);
                    bytesRead = sourceStream.Read(buffer, 0, length);
                    length = length - bytesRead;
                    offSet = (bytesRead == 0) ? 0 : (sourceLength - length);//(length - bytesRead);                  
                }
            }
            catch (Exception ex)
            {
                string error = ex.ToString();
                return offSet;
            }
            finally
            {
                destinationStream.Close();
                sourceStream.Close();
            }
            return offSet;
        }
    }

調用方法為：

class1 ftpClientService = new class1();   //實例化class1類對象
ftpClientService.UploadFile("D:\\456.png",  new Uri("ftp://192.18.13.11/123.png“), 0, WebRequestMethods.Ftp.UploadFile);//調用class1類的UploadFile方法上傳

2.從ftp下載文件

下載的方法代碼如下：

        /// <summary> 
        /// 下載文件 
        /// </summary> 
        /// <param name="localFileName">下載的ftp的文件路徑及文件名</param> 
        /// <param name="ftpFileName">本地文件路徑及文件名（文件名可重命名）</param> 
        /// <returns>返回值</returns>
        public bool fileDownload(string ftpFileName, string localFileName)
        {
            bool success = false;
            FtpWebRequest ftpWebRequest = null;
            FtpWebResponse ftpWebResponse = null;
            Stream ftpResponseStream = null;
            FileStream outputStream = null;
            try
            {
                outputStream = new FileStream(localFileName, FileMode.Create);
                string uri = ftpFileName;
                ftpWebRequest = (FtpWebRequest)FtpWebRequest.Create(new Uri(uri));
                ftpWebRequest.Credentials = new NetworkCredential(ftpUser, ftpPassword);
                ftpWebRequest.UseBinary = true;
                ftpWebRequest.Method = WebRequestMethods.Ftp.DownloadFile;
                ftpWebResponse = (FtpWebResponse)ftpWebRequest.GetResponse();
                ftpResponseStream = ftpWebResponse.GetResponseStream();
                long contentLength = ftpWebResponse.ContentLength;
                int bufferSize = 20480;
                byte[] buffer = new byte[bufferSize];
                int readCount;
                readCount = ftpResponseStream.Read(buffer, 0, bufferSize);
                while (readCount > 0)
                {
                    outputStream.Write(buffer, 0, readCount);
                    readCount = ftpResponseStream.Read(buffer, 0, bufferSize);
                }
                success = true;
            }
            catch (Exception)
            {
                success = false;
            }
            finally
            {
                if (outputStream != null)
                {
                    outputStream.Close();
                }
                if (ftpResponseStream != null)
                {
                    ftpResponseStream.Close();
                }
                if (ftpWebResponse != null)
                {
                    ftpWebResponse.Close();
                }
            }
            return success;
        }

調用方法為：

　　　　　　　class1 ftpClient2 = new class1();  //實例化類FTPClient
            ftpClient2.fileDownload(ftp://192.18.13.11/123.png","D:\\123.png);     //下載文件

3.在ftp上重命名文件

對ftp文件的重命名，方法代碼如下：

        /// <summary> 
        /// 重命名 
        /// </summary> 
        /// <param name="ftpPath">ftp文件路徑(不包含文件名)</param> 
        /// <param name="currentFilename">ftp文件的當前文件名</param> 
        /// <param name="newFilename">ftp文件的重命名后的新文件名</param> 
        /// <returns>返回值</returns>
        public bool fileRename(string ftpPath, string currentFileName, string newFileName)
        {
            bool success = false;
            FtpWebRequest ftpWebRequest = null;
            FtpWebResponse ftpWebResponse = null;
            Stream ftpResponseStream = null;
            try
            {
                string uri = ftpPath + currentFileName;
                ftpWebRequest = (FtpWebRequest)FtpWebRequest.Create(new Uri(uri));
                ftpWebRequest.Credentials = new NetworkCredential(ftpUser, ftpPassword);
                ftpWebRequest.UseBinary = true;
                ftpWebRequest.Method = WebRequestMethods.Ftp.Rename;
                ftpWebRequest.RenameTo = newFileName;
                ftpWebResponse = (FtpWebResponse)ftpWebRequest.GetResponse();
                ftpResponseStream = ftpWebResponse.GetResponseStream();
            }
            catch (Exception)
            {
                success = false;
            }
            finally
            {
                if (ftpResponseStream != null)
                {
                    ftpResponseStream.Close();
                }
                if (ftpWebResponse != null)
                {
                    ftpWebResponse.Close();
                }
            }
            return success;
        }

調用方法為：

            class1 ftpClient3 = new class1();  //實例化類對象
            ftpClient3.fileRename(ftp://192.18.13.11/, "123.png", "456.png");      //ftp上重命名文件

 

4.刪除ftp上的文件

刪除ftp上文件的方法代碼為：

        /// <summary>
        /// 刪除文件
        /// </summary>
        /// <param name="ftpPath">ftp文件路徑(不包含文件名)</param>
        /// <param name="ftpName">文件名</param>
        /// <returns>返回值</returns>
        public bool fileDelete(string ftpPath, string ftpName)
        {
            bool success = false;
            FtpWebRequest ftpWebRequest = null;
            FtpWebResponse ftpWebResponse = null;
            Stream ftpResponseStream = null;
            StreamReader streamReader = null;
            try
            {
                string uri = ftpPath + ftpName;
                ftpWebRequest = (FtpWebRequest)FtpWebRequest.Create(new Uri(uri));
                ftpWebRequest.Credentials = new NetworkCredential(ftpUser, ftpPassword);
                ftpWebRequest.KeepAlive = false;
                ftpWebRequest.Method = WebRequestMethods.Ftp.DeleteFile;
                ftpWebResponse = (FtpWebResponse)ftpWebRequest.GetResponse();
                long size = ftpWebResponse.ContentLength;
                ftpResponseStream = ftpWebResponse.GetResponseStream();
                streamReader = new StreamReader(ftpResponseStream);
                string result = String.Empty;
                result = streamReader.ReadToEnd();
                success = true;
            }
            catch (Exception)
            {
                success = false;
            }
            finally
            {
                if (streamReader != null)
                {
                    streamReader.Close();
                }
                if (ftpResponseStream != null)
                {
                    ftpResponseStream.Close();
                }
                if (ftpWebResponse != null)
                {
                    ftpWebResponse.Close();
                }
            }
            return success;
        }

調用方法：

            class1 ftpClient4 = new class1();  //實例化類對象
            ftpClient4.fileDelete(ftp://192.18.13.11/, "456.png");     //刪除ftp文件

5.檢查ftp上某文件是否存在

方法代碼為：

        /// <summary> 
        /// 檢查文件是否存在 
        /// </summary> 
        /// <param name="ftpPath"></param> 
        /// <param name="ftpName"></param> 
        /// <returns></returns> 
        public bool fileCheckExist(string ftpPath, string ftpName)
        {
            bool success = false;
            FtpWebRequest ftpWebRequest = null;
            WebResponse webResponse = null;
            StreamReader reader = null;
            try
            {
                string url = ftpPath;
                ftpWebRequest = (FtpWebRequest)FtpWebRequest.Create(new Uri(url));
                ftpWebRequest.Credentials = new NetworkCredential(ftpUser, ftpPassword);
                ftpWebRequest.Method = WebRequestMethods.Ftp.ListDirectory;
                ftpWebRequest.KeepAlive = false;
                webResponse = ftpWebRequest.GetResponse();
                reader = new StreamReader(webResponse.GetResponseStream());
                string line = reader.ReadLine();
                while (line != null)
                {
                    if (line == ftpName)
                    {
                        success = true;
                        break;
                    }
                    line = reader.ReadLine();
                }
            }
            catch (Exception)
            {
                success = false;
            }
            finally
            {
                if (reader != null)
                {
                    reader.Close();
                }
                if (webResponse != null)
                {
                    webResponse.Close();
                }
            }
            return success;
        }

調用方法為：

            class1 ftpClient5 = new class1();  //實例化類對象
            bool flag = ftpClient5.fileCheckExist(ftp://192.18.13.11/, "123.png");    //檢查文件是否存在
            if (flag == true)
            {
                this.Response.Write("<script>alert('文件存在！')</script>");
            }
            else
            {
                this.Response.Write("<script>alert('文件不存在！')</script>");
            }