如何发送文件多一次

有两个C＃项目：一个项目用于客户端，另一个项目用于服务器。 第一步是运行服务器，然后选择目标文件夹，然后运行客户端项目，选择一些text.txt发送到服务器的目标文件夹。 只有客户端才能将文件发送到服务器

演示：

1.choosing file target 2.client sends +------------+ | tar folder | <---------------- text.txt +------------+ 

这工作正常，但我希望它每隔几分钟自动发送text.txt，所以我添加了while(true)循环和Thread.Sleep(10000)但是alaway给出了Exceptions。 我的意思是，它不会让我再发送一次。

在这里的客户端类我试图放一个while循环：

  public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e)//browse btn { string n; byte[] b1; TcpClient client; OpenFileDialog op; Stream s; StreamWriter sw; op = new OpenFileDialog(); if (op.ShowDialog() == DialogResult.OK) { string t = textBox1.Text; t = op.FileName; FileInfo fi = new FileInfo(textBox1.Text = op.FileName); n = fi.Name + "." + fi.Length; client = new TcpClient("127.0.0.1", 8100);//"127.0.0.1", 5055 sw = new StreamWriter(client.GetStream()); s = client.GetStream(); b1 = File.ReadAllBytes(op.FileName); // s = client.GetStream(); while (true) { s.Write(b1, 0, b1.Length); sw.WriteLine(n); sw.Flush(); //sw.Close(); s.Close();//added by me Thread.Sleep(18000); } sw.Flush(); client.Close(); // label2.Text = "File Transferred...."; } } 

服务器类：

 public Form1() { InitializeComponent(); } string rd; byte[] b1; string v; int m=20;//number of byts TcpListener list; TcpClient client; int port = 8100;//5050 int port1 = 8100;//5055 IPAddress localAddr = IPAddress.Parse("127.0.0.1"); private void button1_Click(object sender, EventArgs e)//browse button { if (folderBrowserDialog1.ShowDialog() == DialogResult.OK) { textBox1.Text = folderBrowserDialog1.SelectedPath; list = new TcpListener(localAddr, port1); list.Start(); Thread incoming_connection = new Thread(ic); incoming_connection.Start(); } } private void ic() { client = list.AcceptTcpClient(); Stream s = client.GetStream(); b1 = new byte[m]; s.Read(b1,0, b1.Length); MessageBox.Show("pathh "+textBox1.Text); File.WriteAllBytes(textBox1.Text+"\\flag.txt", b1);// the left side us the name of the written file //list.Stop(); //client.Close(); // label1.Text = "File Received......"; } private void Form2_Load(object sender, EventArgs e) { list = new TcpListener(localAddr, port); // TcpListener list = new TcpListener(port); list.Start(); TcpClient client = list.AcceptTcpClient(); MessageBox.Show("Client trying to connect"); StreamReader sr = new StreamReader(client.GetStream()); rd = sr.ReadLine(); v = rd.Substring(rd.LastIndexOf('.') + 1); m = int.Parse(v); // list.Stop(); // client.Close(); } 

有关

Answer 1

尝试更改为：

 while (true) { using (var client = new TcpClient("127.0.0.1", 8100))//"127.0.0.1", 5055 using (var sw = new StreamWriter(client.GetStream())) using (var s = client.GetStream()) { b1 = File.ReadAllBytes(op.FileName); // s = client.GetStream(); s.Write(b1, 0, b1.Length); sw.WriteLine(n); sw.Flush(); } Thread.Sleep(18000); } 

using语句有助于处理对象。

或者，如果要保持连接打开，请尝试：

 using (var client = new TcpClient("127.0.0.1", 8100))//"127.0.0.1", 5055 while (true) { using (var sw = new StreamWriter(client.GetStream())) using (var s = client.GetStream()) { b1 = File.ReadAllBytes(op.FileName); // s = client.GetStream(); s.Write(b1, 0, b1.Length); sw.WriteLine(n); sw.Flush(); } Thread.Sleep(18000); } 

Answer 2

好的，这是你的问题：

在第一个循环中，它按预期正常工作，因为所有内容都已正确初始化，但在发送第一个文件后，您调用s.Close（）;

 while (true) { s.Write(b1, 0, b1.Length); sw.WriteLine(n); sw.Flush(); //sw.Close(); s.Close();//added by me Thread.Sleep(18000); } 

现在发生的事情是在第一个循环之后关闭流然后在第二个循环上它已经是“Disposed”。

要修复移动s.Close（）; 离开循环并进入断开连接按钮事件或应用程序关闭事件。

另外我建议不要使用Thread.Sleep（interval）; 这是因为sleep冻结了你的线程，并且.NET中的主线程用于你的接口，因此冻结该线程是非常糟糕的。

像以前的post一样创建一个新线程：

 using System.Threading; Stream s; byte[] b1; TcpClient client; OpenFileDialog op; StreamWriter sw; Thread thread = new Thread(sendFile); string fn; string n; threadExit = false; Int32 interval = 18000; public Form1() { InitializeComponent(); } private void Form1_OnLoad(object sender,EventArgs e) { op = new OpenFileDialog(); client = new TcpClient("127.0.0.1", 8100);//"127.0.0.1", 5055 sw = new StreamWriter(client.GetStream()); s = client.GetStream(); //It would be your responsibility to move this code to the proper place //because now it tries to open the connection when your app loads } private void sendFile() { while (!threadExit) { b1 = File.ReadAllBytes(fn); s.Write(b1, 0, b1.Length); sw.WriteLine(n); sw.Flush(); Thread.Sleep(interval); } } private void button1_Click(object sender, EventArgs e) { if (op.ShowDialog() == DialogResult.OK) { fn = op.FileName; FileInfo fi = new FileInfo(textBox1.Text = op.FileName); n = fi.Name + "." + fi.Length; thread.Start(); } //It would be a good idea to add an indicator to signal that another thread is trying to send the file at a set interval } private void Form1_Close(object sender, EventArgs e) { s.Close(); client.Close(); threadExit = true; Application.Exit(); } 

并且记得为此线程使用try catch块，否则如果发生exception则不会处理得非常好。 还要记住，在此线程运行时关闭应用程序将保持您的应用程序处于打开状态，直到您手动终止该进程，因此在应用程序关闭事件中记住要杀死该线程。

而且关闭是发送线程退出的信号，但最后可能需要18秒才能完全退出，另一种解决方案是使用thread.Abort（）; 但这是一个肮脏的退出，它很可能会抛出exception。

再一次记得阅读线程，这是一个快速，糟糕的版本，它应该如何在生产环境中。