c# SSH ,SFTP

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Renci.SshNet;

namespace TestSFTP
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        public class sFtpHelper

        {

            public static int DownloadFtp(string filePath, string localPath, string fileName, string ftpServerIP, string ftpPort, string ftpUserID, string ftpPassword)

            {

                string localFileName = localPath + "\\" + fileName;

                string remoteFileName = filePath+ "/"+ fileName;
                try

                {

                    using (var sftp = new SftpClient(ftpServerIP, Convert.ToInt32(ftpPort), ftpUserID, ftpPassword))

                    {

                        sftp.Connect();

                        using (var file = File.Open(localFileName,FileMode.OpenOrCreate))

                        {

                            sftp.DownloadFile(remoteFileName, file);

                        }

                        sftp.Disconnect();

                        Console.WriteLine("下载文件成功,文件路径："+localFileName);

                        return 0;

                    }

                }

                catch (Exception e)

                {

                    MessageBox.Show("下载失败，原因："+e.Message );

                    return -2;

                }

            }

            public static int UploadFtp(string filePath, string localPath, string filename, string ftpServerIP, string ftpPort, string ftpUserID, string ftpPassword)

            {

                string localFileName = localPath + "\\" + filename;
                string remoteFileName = "/"+filePath+"/"+filename;

                try

                {

                    using (var sftp = new SftpClient(ftpServerIP, Convert.ToInt32(ftpPort), ftpUserID, ftpPassword))

                    {

                        sftp.Connect();

                        using (var file = File.OpenWrite(localFileName))

                        {

                            sftp.UploadFile(file, remoteFileName);

                        }

                        sftp.Disconnect();

                        Console.WriteLine("上传文件成功,文件路径："+localFileName);

                        return 0;

                    }

                }

                catch (Exception ex)

                {

                    Console.WriteLine("上传失败，原因："+ex.Message );

                    return -2;

                }

            }

        }

        private void button1_Click(object sender, EventArgs e)
        {
            string sftpHost = "sftp.xxx.com";
            string sFile= "aaa.txt";
            sFtpHelper.DownloadFtp("/upload/weblicense/dd", "d:\\",sFile , sftpHost, "22", "username222", "pwd123");

        }

}

}

　　

完整实例（包含显示下载进度）：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Renci.SshNet;
using System.Threading.Tasks;
using Renci.SshNet.Sftp;
using System.Diagnostics;

namespace TestSFTP
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        public int DownloadFtp(string filePath, string localPath, string fileName, string ftpServerIP, string ftpPort, string ftpUserID, string ftpPassword)
        {

            string localFileName = localPath + "\\" + fileName;

            string remoteFileName = filePath + "/" + fileName;
            try
            {

                using (var sftp = new SftpClient(ftpServerIP, Convert.ToInt32(ftpPort), ftpUserID, ftpPassword))
                {
                    sftp.Connect();
                    using (var file = File.Open(localFileName, FileMode.OpenOrCreate))
                    {

                        sftp.DownloadFile(remoteFileName, file);
                        //sftp.BeginDownloadFile(
                    }
                    sftp.Disconnect();

                    display("下载文件成功,文件路径：" + localFileName);

                    return 0;

                }

            }

            catch (Exception e)
            {
                display("下载失败，原因：" + e.Message);
                return -2;

            }

        }

        public int UploadFtp(string filePath, string localPath, string filename, string ftpServerIP, string ftpPort, string ftpUserID, string ftpPassword)
        {

            string localFileName = localPath + "\\" + filename;
            string remoteFileName = "/" + filePath + "/" + filename;

            try
            {

                using (var sftp = new SftpClient(ftpServerIP, Convert.ToInt32(ftpPort), ftpUserID, ftpPassword))
                {

                    sftp.Connect();

                    using (var file = File.OpenWrite(localFileName))
                    {

                        sftp.UploadFile(file, remoteFileName);

                    }

                    sftp.Disconnect();

                    Console.WriteLine("上传文件成功,文件路径：" + localFileName);

                    return 0;

                }

            }

            catch (Exception ex)
            {

                Console.WriteLine("上传失败，原因：" + ex.Message);

                return -2;

            }

        }

        public int DownloadFtpWithProgress(string filePath, string localPath, string fileName, string ftpServerIP, string ftpPort, string ftpUserID, string ftpPassword)
        {

            string localFileName = localPath + "\\" + fileName;

            string remoteFileName = filePath + "/" + fileName;
            try
            {

                using (var sftp = new SftpClient(ftpServerIP, Convert.ToInt32(ftpPort), ftpUserID, ftpPassword))
                {
                    sftp.Connect();
                    bool IsExists = sftp.Exists(remoteFileName);
                    if (!IsExists)
                    {

                        return 0;
                    }

                    //get the attributes of the file (namely the size)
                    SftpFileAttributes att = sftp.GetAttributes(remoteFileName);
                    long fileSize = att.Size;
                    //download the file as a memory stream and convert to a file stream
                    using (MemoryStream ms = new MemoryStream())
                    {
                        IAsyncResult asyncr = sftp.BeginDownloadFile(remoteFileName, ms);
                        SftpDownloadAsyncResult sftpAsyncr = (SftpDownloadAsyncResult)asyncr;
                        while (!sftpAsyncr.IsCompleted)
                        {
                            int pct = (int)(((double)sftpAsyncr.DownloadedBytes / fileSize) * 100);
                            Debug.Print("Downloaded {0} of {1} ({2}%).", sftpAsyncr.DownloadedBytes, fileSize, pct);
                            Text=string.Format ("Downloaded {0} of {1} ({2}%).", sftpAsyncr.DownloadedBytes, fileSize, pct);
                            pgbMain.Value = pct;//pgbMain is the progressBar ui control
                            Application.DoEvents();
                        }

                        sftp.EndDownloadFile(asyncr);
                        //write the memory stream to the file stream
                        var fs = File.Open(localFileName, FileMode.Create);
                        ms.WriteTo(fs);
                        fs.Close();
                        ms.Close();

                    }
                    sftp.Disconnect();

                    display("下载文件成功,文件路径：" + localFileName);
                    return 0;

                }

            }

            catch (Exception e)
            {
                display("下载失败，原因：" + e.Message);
                return -2;

            }

        }

        void display(string s)
        {

            richTextBox1.AppendText(s + "\r\n");
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string sftpHost = "sftp.xxx.com";
            string sFile = "SWMM7ActiveProductDevelopment-GuangshuWang.mem";
            DownloadFtpWithProgress("/upload/weblicense/swmm7000", "d:\\", sFile, sftpHost, "22", "username", "pwd...");

        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

    }

}

　　

界面代码：

namespace TestSFTP
{
    partial class Form1
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.button1 = new System.Windows.Forms.Button();
            this.richTextBox1 = new System.Windows.Forms.RichTextBox();
            this.pgbMain = new System.Windows.Forms.ProgressBar();
            this.SuspendLayout();
            //
            // button1
            //
            this.button1.Location = new System.Drawing.Point(293, 23);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(241, 67);
            this.button1.TabIndex = 0;
            this.button1.Text = "button1";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            //
            // richTextBox1
            //
            this.richTextBox1.Location = new System.Drawing.Point(76, 151);
            this.richTextBox1.Name = "richTextBox1";
            this.richTextBox1.Size = new System.Drawing.Size(639, 244);
            this.richTextBox1.TabIndex = 1;
            this.richTextBox1.Text = "";
            //
            // pgbMain
            //
            this.pgbMain.Location = new System.Drawing.Point(106, 107);
            this.pgbMain.Name = "pgbMain";
            this.pgbMain.Size = new System.Drawing.Size(609, 23);
            this.pgbMain.TabIndex = 2;
            //
            // Form1
            //
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(800, 450);
            this.Controls.Add(this.pgbMain);
            this.Controls.Add(this.richTextBox1);
            this.Controls.Add(this.button1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.Load += new System.EventHandler(this.Form1_Load);
            this.ResumeLayout(false);

        }

        #endregion

        private System.Windows.Forms.Button button1;
        private System.Windows.Forms.RichTextBox richTextBox1;
        private System.Windows.Forms.ProgressBar pgbMain;
    }
}

　　

SSH.NET is a Secure Shell (SSH) library for .NET, optimized for parallelism.

【从nuget中下载SSH.NET】

摘自 http://www.cnblogs.com/cbread/p/6202069.html