程序代码：

SerialPort spSend;  //spSend,spReceive用虚拟串口连接，它们之间可以相互传输数据。spSend发送数据  
SerialPort spReceive;  //spReceive接受数据  
TextBox txtSend;  //发送区  
TextBox txtReceive;  //接受区  
Button btnSend;  //数据发送按钮  
delegate void HandleInterfaceUpdateDelegate(string text);  //委托，此为重点  
HandleInterfaceUpdateDelegate interfaceUpdateHandle;  
 
public void InitClient()  //窗体控件已在初始化  
{  
  interfaceUpdateHandle = new HandleInterfaceUpdateDelegate(UpdateTextBox);  //实例化委托对象  
  spSend.Open();  //SerialPort对象在程序结束前必须关闭，在此说明  
  spReceive.DataReceived += Ports.SerialDataReceivedEventHandler(spReceive_DataReceived);  
  spReceive.ReceivedBytesThreshold = 1;  
  spReceive.Open();  
}  
 
public void btnSend_Click(object sender,EventArgs e)  
{  
  spSend.WriteLine(txtSend.Text);  
}  
 
public void spReceive_DataReceived(object sender,Ports.SerialDataReceivedEventArgs e)  
{  
  byte[] readBuffer = new byte[spReceive.ReadBufferSize];  
  spReceive.Read(readBuffer, 0, readBuffer.Length);  
  this.Invoke(interfaceUpdateHandle, new string[] { Encoding.Unicode.GetString(readBuffer) });  
}  
 
private void UpdateTextBox(string text)  
{  
  txtReceive.Text = text;  
}