如何使用C#開發Socket通訊

下面的示例顯示如何使用 Socket 類向 HTTP 服務器發送數據和接收響應。

[C#]
public string DoSocketGet(string server)
{
//Sets up variables and a string to write to the server
Encoding ASCII = Encoding.ASCII;//此處如果需要傳輸中文字串，需要設置成Encoding.Default
string Get = "GET / HTTP/1.1/r/nHost: " + server +
"/r/nConnection: Close/r/n/r/n";
Byte[] ByteGet = ASCII.GetBytes(Get);
Byte[] RecvBytes = new Byte[256];
String strRetPage = null;

// IPAddress and IPEndPoint represent the endpoint that will
// receive the request.
// Get the first IPAddress in the list using DNS.
IPAddress hostadd = Dns.Resolve(server).AddressList[0];
IPEndPoint EPhost = new IPEndPoint(hostadd, 80);

//Creates the Socket for sending data over TCP.
Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Stream,
ProtocolType.Tcp );

// Connects to the host using IPEndPoint.
s.Connect(EPhost);
if (!s.Connected)
{
strRetPage = "Unable to connect to host";
return strRetPage;
}

// Sends the GET text to the host.
s.Send(ByteGet, ByteGet.Length, SocketFlags.None);

// Receives the page, looping until all bytes are received
Int32 bytes = s.Receive(RecvBytes, RecvBytes.Length, 0);
strRetPage = "Default HTML page on " + server + ":/r/n";
strRetPage = strRetPage + ASCII.GetString(RecvBytes, 0, bytes);

while (bytes > 0)
{
bytes = s.Receive(RecvBytes, RecvBytes.Length, SocketFlags.None);
strRetPage = strRetPage + ASCII.GetString(RecvBytes, 0, bytes);
}
//如果想立即關閉連接則調用 s.Close();
return strRetPage;
}