我正在编写一个简单的客户端服务器套接字程序，无法弄清楚为什么我的客户端仅在第一次按下发送按钮时发送。
第二次“nwStream.Write（bytesToSend，0，bytesToSend.Length）;”被调用，服务器无法获取数据......
注意：我已经注释掉了从服务器到客户端的回显，因为服务器在回显后关闭了连接。我希望连接保持打开状态。
请帮我发两次数据......
这是C＃FORM客户端代码
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
TcpClient client;
private void Form1_Load(object sender, EventArgs e)
{
textBox_IP.Text = "192.168.0.72";
}
const int PORT_NO = 11000;
private void button_Start_Click(object sender, EventArgs e)
{
client = new TcpClient(textBox_IP.Text, PORT_NO);
textBox_MsgToSend.Text = "Started";
}
private void button_Send_Click(object sender, EventArgs e)
{
string textToSend = textBox_MsgToSend.Text + " " + DateTime.Now.ToString();
textToSend += "<EOF>";
NetworkStream nwStream = client.GetStream();
byte[] bytesToSend = ASCIIEncoding.ASCII.GetBytes(textToSend);
//---send the text---
textBox_Sending.Text = textToSend;
textBox_Size.Text = bytesToSend.Length.ToString();
nwStream.Write(bytesToSend, 0, bytesToSend.Length);
// commented out as the server does not echo anything back
//---read back the text---
// byte[] bytesToRead = new byte[client.ReceiveBufferSize];
// int bytesRead = nwStream.Read(bytesToRead, 0, client.ReceiveBufferSize);
// textBox_Received.Text = bytesRead.ToString();
}
private void button_Close_Click(object sender, EventArgs e)
{
client.Close();
textBox_MsgToSend.Text = "Closed";
}
}
以下是表单设计器代码：
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.button_Start = new System.Windows.Forms.Button();
this.button_Send = new System.Windows.Forms.Button();
this.button_Close = new System.Windows.Forms.Button();
this.textBox_MsgToSend = new System.Windows.Forms.TextBox();
this.textBox_Received = new System.Windows.Forms.TextBox();
this.textBox_IP = new System.Windows.Forms.TextBox();
this.label1 = new System.Windows.Forms.Label();
this.label2 = new System.Windows.Forms.Label();
this.textBox_Sending = new System.Windows.Forms.TextBox();
this.label3 = new System.Windows.Forms.Label();
this.textBox_Size = new System.Windows.Forms.TextBox();
this.SuspendLayout();
//
// button_Start
//
this.button_Start.Location = new System.Drawing.Point(30, 28);
this.button_Start.Name = "button_Start";
this.button_Start.Size = new System.Drawing.Size(75, 23);
this.button_Start.TabIndex = 0;
this.button_Start.Text = "Start";
this.button_Start.UseVisualStyleBackColor = true;
this.button_Start.Click += new System.EventHandler(this.button_Start_Click);
//
// button_Send
//
this.button_Send.Location = new System.Drawing.Point(30, 73);
this.button_Send.Name = "button_Send";
this.button_Send.Size = new System.Drawing.Size(75, 23);
this.button_Send.TabIndex = 1;
this.button_Send.Text = "Send";
this.button_Send.UseVisualStyleBackColor = true;
this.button_Send.Click += new System.EventHandler(this.button_Send_Click);
//
// button_Close
//
this.button_Close.Location = new System.Drawing.Point(30, 172);
this.button_Close.Name = "button_Close";
this.button_Close.Size = new System.Drawing.Size(75, 23);
this.button_Close.TabIndex = 2;
this.button_Close.Text = "Close";
this.button_Close.UseVisualStyleBackColor = true;
this.button_Close.Click += new System.EventHandler(this.button_Close_Click);
//
// textBox_MsgToSend
//
this.textBox_MsgToSend.Location = new System.Drawing.Point(120, 73);
this.textBox_MsgToSend.Name = "textBox_MsgToSend";
this.textBox_MsgToSend.Size = new System.Drawing.Size(207, 20);
this.textBox_MsgToSend.TabIndex = 3;
//
// textBox_Received
//
this.textBox_Received.Location = new System.Drawing.Point(120, 174);
this.textBox_Received.Name = "textBox_Received";
this.textBox_Received.Size = new System.Drawing.Size(207, 20);
this.textBox_Received.TabIndex = 4;
//
// textBox_IP
//
this.textBox_IP.Location = new System.Drawing.Point(120, 28);
this.textBox_IP.Name = "textBox_IP";
this.textBox_IP.Size = new System.Drawing.Size(128, 20);
this.textBox_IP.TabIndex = 5;
//
// label1
//
this.label1.AutoSize = true;
this.label1.Location = new System.Drawing.Point(117, 57);
this.label1.Name = "label1";
this.label1.Size = new System.Drawing.Size(90, 13);
this.label1.TabIndex = 7;
this.label1.Text = "Message to Send";
//
// label2
//
this.label2.AutoSize = true;
this.label2.Location = new System.Drawing.Point(117, 96);
this.label2.Name = "label2";
this.label2.Size = new System.Drawing.Size(49, 13);
this.label2.TabIndex = 9;
this.label2.Text = "Sending:";
//
// textBox_Sending
//
this.textBox_Sending.Location = new System.Drawing.Point(120, 112);
this.textBox_Sending.Name = "textBox_Sending";
this.textBox_Sending.ReadOnly = true;
this.textBox_Sending.Size = new System.Drawing.Size(207, 20);
this.textBox_Sending.TabIndex = 8;
//
// label3
//
this.label3.AutoSize = true;
this.label3.Location = new System.Drawing.Point(330, 96);
this.label3.Name = "label3";
this.label3.Size = new System.Drawing.Size(27, 13);
this.label3.TabIndex = 11;
this.label3.Text = "Size";
//
// textBox_Size
//
this.textBox_Size.Location = new System.Drawing.Point(333, 112);
this.textBox_Size.Name = "textBox_Size";
this.textBox_Size.ReadOnly = true;
this.textBox_Size.Size = new System.Drawing.Size(65, 20);
this.textBox_Size.TabIndex = 10;
//
// Form1
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(447, 262);
this.Controls.Add(this.label3);
this.Controls.Add(this.textBox_Size);
this.Controls.Add(this.label2);
this.Controls.Add(this.textBox_Sending);
this.Controls.Add(this.label1);
this.Controls.Add(this.textBox_IP);
this.Controls.Add(this.textBox_Received);
this.Controls.Add(this.textBox_MsgToSend);
this.Controls.Add(this.button_Close);
this.Controls.Add(this.button_Send);
this.Controls.Add(this.button_Start);
this.Name = "Form1";
this.Text = "Client";
this.Load += new System.EventHandler(this.Form1_Load);
this.ResumeLayout(false);
this.PerformLayout();
}
#endregion
private System.Windows.Forms.Button button_Start;
private System.Windows.Forms.Button button_Send;
private System.Windows.Forms.Button button_Close;
private System.Windows.Forms.TextBox textBox_MsgToSend;
private System.Windows.Forms.TextBox textBox_Received;
private System.Windows.Forms.TextBox textBox_IP;
private System.Windows.Forms.Label label1;
private System.Windows.Forms.Label label2;
private System.Windows.Forms.TextBox textBox_Sending;
private System.Windows.Forms.Label label3;
private System.Windows.Forms.TextBox textBox_Size;
}
现在服务器
服务器是一个控制台应用程序，它有两个类和一个主
// State object for reading client data asynchronously
public class StateObject
{
// Client socket.
public Socket workSocket = null;
// Size of receive buffer.
public const int BufferSize = 1024;
// Receive buffer.
public byte[] buffer = new byte[BufferSize];
// Received data string.
public StringBuilder sb = new StringBuilder();
}
这是服务器代码：
public class AsynchronousSocketListener
{
// Thread signal.
public static ManualResetEvent allDone = new ManualResetEvent(false);
public AsynchronousSocketListener()
{
}
public static void StartListening(string ip)
{
// Data buffer for incoming data.
byte[] bytes = new Byte[1024];
IPAddress address = IPAddress.Parse(ip);
Console.WriteLine("listening on IP " + ip + " Port " + "11000");
IPEndPoint localEndPoint = new IPEndPoint(address, 11000);
// Create a TCP/IP socket.
Socket listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
// Bind the socket to the local endpoint and listen for incoming connections.
try
{
listener.Bind(localEndPoint);
listener.Listen(100);
while (true)
{
// Set the event to nonsignaled state.
allDone.Reset();
// Start an asynchronous socket to listen for connections.
Console.WriteLine("Waiting for a connection...");
listener.BeginAccept(new AsyncCallback(AcceptCallback), listener);
// Wait until a connection is made before continuing.
allDone.WaitOne();
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
Console.WriteLine("\nPress ENTER to continue...");
Console.Read();
}
public static void AcceptCallback(IAsyncResult ar)
{
// Signal the main thread to continue.
allDone.Set();
// Get the socket that handles the client request.
Socket listener = (Socket)ar.AsyncState;
Socket handler = listener.EndAccept(ar);
Console.WriteLine("Connected...");
// Create the state object.
StateObject state = new StateObject();
state.workSocket = handler;
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), state);
}
public static void ReadCallback(IAsyncResult ar)
{
Console.WriteLine("ReadCallback");
string content = string.Empty;
// Retrieve the state object and the handler socket
// from the asynchronous state object.
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.workSocket;
// Read data from the client socket.
int bytesRead = handler.EndReceive(ar);
if (bytesRead > 0)
{
// There might be more data, so store the data received so far.
state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));
// Check for end-of-file tag. If it is not there, read
// more data.
content = state.sb.ToString();
if (content.IndexOf("<EOF>") > -1)
{
// All the data has been read from the
// client. Display it on the console.
Console.WriteLine("Read {0} bytes from socket. \n Data : {1}", content.Length, content);
// I commented this out as when the send completes, the server closes the connection... I want the connection to remain open
// Echo the data back to the client.
//Send(handler, content);
}
else
{
// Not all data received. Get more.
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReadCallback), state);
}
}
}
private static void Send(Socket handler, String data)
{
// Convert the string data to byte data using ASCII encoding.
byte[] byteData = Encoding.ASCII.GetBytes(data);
Console.WriteLine("Echo back to client : " + data);
// Begin sending the data to the remote device.
handler.BeginSend(byteData, 0, byteData.Length, 0, new AsyncCallback(SendCallback), handler);
}
private static void SendCallback(IAsyncResult ar)
{
try
{
// Retrieve the socket from the state object.
Socket handler = (Socket)ar.AsyncState;
// Complete sending the data to the remote device.
int bytesSent = handler.EndSend(ar);
Console.WriteLine("Sent {0} bytes to client.", bytesSent);
handler.Shutdown(SocketShutdown.Both);
handler.Close();
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
这里是主要的：
public static int Main(String[] args)
{
StartListening( "192.168.0.72" );
return 0;
}
尝试1：
我在public static void AcceptCallback（IAsyncResult ar）函数中试过这个：
while(true)
{
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), state);
}
ATTEMPT2：
Per SpaceghostAli的回复/代码：不起作用......第二次发送时崩溃
public static void ReadCallback(IAsyncResult ar)
{
string content = string.Empty;
// Retrieve the state object and the handler socket
// from the asynchronous state object.
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.workSocket;
// Read data from the client socket.
int bytesRead = handler.EndReceive(ar);
if (bytesRead > 0)
{
Console.WriteLine("ReadCallback");
// There might be more data, so store the data received so far.
state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));
// Check for end-of-file tag. If it is not there, read
// more data.
content = state.sb.ToString();
if (content.IndexOf("<EOF>") > -1)
{
// All the data has been read from the
// client. Display it on the console.
Console.WriteLine("Read {0} bytes from socket. Data : {1}", content.Length, content);
state = new StateObject();
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), state);
// Echo the data back to the client.
// Send(handler, content);
}
else
{
// Not all data received. Get more.
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), state);
}
}
}
尝试3：
根据David所说的另一种尝试，但在功能结束时重置BeginReceive - WORKS！
public static void ReadCallback(IAsyncResult ar)
{
string content = string.Empty;
// Retrieve the state object and the handler socket
// from the asynchronous state object.
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.workSocket;
// Read data from the client socket.
int bytesRead = handler.EndReceive(ar);
if (bytesRead > 0)
{
Console.WriteLine("ReadCallback");
// There might be more data, so store the data received so far.
state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));
// Check for end-of-file tag. If it is not there, read
// more data.
content = state.sb.ToString();
if (content.IndexOf("<EOF>") > -1)
{
// All the data has been read from the
// client. Display it on the console.
Console.WriteLine("Read {0} bytes from socket. Data : {1}", content.Length, content);
// Echo the data back to the client.
Send(handler, content);
}
else
{
// Not all data received. Get more.
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), state);
}
}
// clear the state object's buffer and queue the next begin receive
state.sb.Clear();
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), state);
}
答案 0 :(得分：2)
一旦您的服务器读取消息然后将其写入控制台，它就永远不会再次开始阅读。它只是退出＆＃34; ReadCallback＆＃34;。服务器的连接保持打开状态，但它将永远不会再读取。
要解决这个问题，你应该开始另一个＆＃34; BeginReceive＆＃34;在你写完最后收到的信息之后。
答案 1 :(得分：2)
我赞成大卫的回答，因为我认为这是正确的，所以请将其标记为这样，这只是为了澄清他根据您的更新意味着什么
public static void ReadCallback(IAsyncResult ar)
{
Console.WriteLine("ReadCallback");
string content = string.Empty;
// Retrieve the state object and the handler socket
// from the asynchronous state object.
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.workSocket;
// Read data from the client socket.
int bytesRead = handler.EndReceive(ar);
if (bytesRead > 0)
{
// There might be more data, so store the data received so far.
state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));
// Check for end-of-file tag. If it is not there, read
// more data.
content = state.sb.ToString();
if (content.IndexOf("<EOF>") > -1)
{
// All the data has been read from the
// client. Display it on the console.
Console.WriteLine("Read {0} bytes from socket. \n Data : {1}", content.Length, content);
// continue reading
state = new StateObject();
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReadCallback), state);
// I commented this out as when the send completes, the server closes the connection... I want the connection to remain open
// Echo the data back to the client.
//Send(handler, content);
}
else
{
// Not all data received. Get more
// start writing at bytesRead in the buffer so you don't lose the partially read data
handler.BeginReceive(state.buffer, bytesRead, StateObject.BufferSize, 0,
new AsyncCallback(ReadCallback), state);
}
}
}