我有一个 C# 作业，我必须制作一个下载管理器，我已经完成了。
这是我的代码：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Net;
namespace DownloadDataFTP
{
public partial class ftpForm : Form
{
public ftpForm()
{
InitializeComponent();
}
private byte[] downloadedData;
//Connects to the FTP server and downloads the file
private void downloadFile(string FTPAddress, string filename, string username, string password)
{
downloadedData = new byte[0];
try
{
//Create FTP request
//Note: format is ftp://server.com/file.ext
FtpWebRequest request = FtpWebRequest.Create(FTPAddress + "/" + filename) as FtpWebRequest;
//Get the file size first (for progress bar)
request.Method = WebRequestMethods.Ftp.GetFileSize;
request.Credentials = new NetworkCredential(username, password);
request.UsePassive = true;
request.UseBinary = true;
request.KeepAlive = true; //don't close the connection
int dataLength = (int)request.GetResponse().ContentLength;
//Now get the actual data
request = FtpWebRequest.Create(FTPAddress + "/" + filename) as FtpWebRequest;
request.Method = WebRequestMethods.Ftp.DownloadFile;
request.Credentials = new NetworkCredential(username, password);
request.UsePassive = true;
request.UseBinary = true;
request.KeepAlive = false; //close the connection when done
//Set up progress bar
progressBar1.Value = 0;
progressBar1.Maximum = dataLength;
lbProgress.Text = "0/" + dataLength.ToString();
//Streams
FtpWebResponse response = request.GetResponse() as FtpWebResponse;
Stream reader = response.GetResponseStream();
//Download to memory
//Note: adjust the streams here to download directly to the hard drive
MemoryStream memStream = new MemoryStream();
byte[] buffer = new byte[1024]; //downloads in chuncks
while (true)
{
Application.DoEvents(); //prevent application from crashing
//Try to read the data
int bytesRead = reader.Read(buffer, 0, buffer.Length);
if (bytesRead == 0)
{
//Nothing was read, finished downloading
progressBar1.Value = progressBar1.Maximum;
lbProgress.Text = dataLength.ToString() + "/" + dataLength.ToString();
Application.DoEvents();
break;
}
else
{
//Write the downloaded data
memStream.Write(buffer, 0, bytesRead);
//Update the progress bar
if (progressBar1.Value + bytesRead <= progressBar1.Maximum)
{
progressBar1.Value += bytesRead;
lbProgress.Text = progressBar1.Value.ToString() + "/" + dataLength.ToString();
progressBar1.Refresh();
Application.DoEvents();
}
}
}
//Convert the downloaded stream to a byte array
downloadedData = memStream.ToArray();
//Clean up
reader.Close();
memStream.Close();
response.Close();
MessageBox.Show("Downloaded Successfully");
}
catch (Exception)
{
MessageBox.Show("Connection error. Please try again!");
}
txtData.Text = downloadedData.Length.ToString();
this.Text = "Group 10 Download and Upload Manager";
username = string.Empty;
password = string.Empty;
}
//Upload file via FTP
private void Upload(string FTPAddress, string filePath, string username, string password)
{
//Create FTP request
FtpWebRequest request = (FtpWebRequest)FtpWebRequest.Create(FTPAddress + "/" + Path.GetFileName(filePath));
request.Method = WebRequestMethods.Ftp.UploadFile;
request.Credentials = new NetworkCredential(username, password);
request.UsePassive = true;
request.UseBinary = true;
request.KeepAlive = false;
//Load the file
FileStream stream = File.OpenRead(filePath);
byte[] buffer = new byte[stream.Length];
stream.Read(buffer, 0, buffer.Length);
stream.Close();
//Upload file
Stream reqStream = request.GetRequestStream();
reqStream.Write(buffer, 0, buffer.Length);
reqStream.Close();
MessageBox.Show("Uploaded Successfully");
}
//get file size for downloading
private void FileSize_down(string FTPAddress, string filename, string username, string password)
{
FtpWebRequest request = FtpWebRequest.Create(FTPAddress + "/" + filename) as FtpWebRequest;
request.Method = WebRequestMethods.Ftp.GetFileSize;
request.Credentials = new NetworkCredential(username, password);
request.UsePassive = true;
request.UseBinary = true;
request.KeepAlive = false;
long dataLength = (long)request.GetResponse().ContentLength;
sizeFile.Text = dataLength.ToString();
}
//Connects to the FTP server and request the list of available files
private void getFileList(string FTPAddress, string username, string password)
{
List<string> files = new List<string>();
try
{
//Create FTP request
FtpWebRequest request = FtpWebRequest.Create(FTPAddress) as FtpWebRequest;
request.Method = WebRequestMethods.Ftp.ListDirectory;
request.Credentials = new NetworkCredential(username, password);
request.UsePassive = true;
request.UseBinary = true;
request.KeepAlive = false;
FtpWebResponse response = request.GetResponse() as FtpWebResponse;
Stream responseStream = response.GetResponseStream();
StreamReader reader = new StreamReader(responseStream);
while (!reader.EndOfStream)
{
Application.DoEvents();
files.Add(reader.ReadLine());
}
//Clean-up
reader.Close();
responseStream.Close(); //redundant
response.Close();
}
catch (Exception)
{
MessageBox.Show("There was an error connecting to the FTP Server");
}
username = string.Empty;
password = string.Empty;
this.Text = "Group 10 Download and Upload Manager"; //Back to normal title
//If the list was successfully received, display it to the user
//through a dialog
if (files.Count != 0)
{
listDialogForm dialog = new listDialogForm(files);
if (dialog.ShowDialog() == DialogResult.OK)
{
//Update the File Name field
txtFileName.Text = dialog.ChosenFile;
}
}
}
//Make sure the FTP server address has ftp:// at the beginning
private void txtFTPAddress_Leave(object sender, EventArgs e)
{
if (!txtFTPAddress.Text.StartsWith("ftp://"))
txtFTPAddress.Text = "ftp://" + txtFTPAddress.Text;
}
private void btnGetList_Click(object sender, EventArgs e)
{
if (txtFTPAddress.Text != "ftp://" && txtFTPAddress.Text != string.Empty)
getFileList(txtFTPAddress.Text, txtUsername.Text, txtPassword.Text);
else
MessageBox.Show("Please enter a FTP address");
}
//Download button
private void btnDownload_Click(object sender, EventArgs e)
{
if (txtFTPAddress.Text != "ftp://" && txtFTPAddress.Text != string.Empty)
if (txtFileName.Text != string.Empty)
{
downloadFile(txtFTPAddress.Text, txtFileName.Text, txtUsername.Text, txtPassword.Text);
saveFile1.FileName = txtFileName.Text;
}
else
MessageBox.Show("Please enter a file name or click the Get File List button");
else
MessageBox.Show("Please enter a FTP address");
}
//Save Button
private void btnSave_Click(object sender, EventArgs e)
{
if (downloadedData != null && downloadedData.Length != 0)
{
if (saveFile1.ShowDialog() == DialogResult.OK)
{
this.Text = "Saving Data...";
Application.DoEvents();
//Write the bytes to a file
FileStream newFile = new FileStream(saveFile1.FileName, FileMode.Create);
newFile.Write(downloadedData, 0, downloadedData.Length);
newFile.Close();
this.Text = "Download Data";
MessageBox.Show("Saved Successfully");
}
}
else
MessageBox.Show("Please download first!");
}
//GetFile button
private void button1_Click(object sender, EventArgs e)
{
FileSize_down(txtFTPAddress.Text, txtFileName.Text, txtUsername.Text, txtPassword.Text);
}
}
}
但是，仍然有一个我不知道如何完成的要求。也就是说，下载完成后，文件位置将自动使用 Window Explorer 打开。
有人能帮我吗？