由于线程实时读串口的效率不是十分高效,因此比较好的方法是事件触发的方式。在SerialPort类中有DataReceived事件,当串口的读缓存有数据到达时则触发DataReceived事件,其中SerialPort.ReceivedBytesThreshold属性决定了当串口读缓存中数据多少个时才触发DataReceived事件,默认为1。
另外,SerialPort.DataReceived事件运行比较特殊,其运行在辅线程,不能与主线程中的显示数据控件直接进行数据传输,必须用间接的方式实现。如下:
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;
}