serialPort_DataReceived事件的问题
本文关键字:问题 事件 DataReceived serialPort | 更新日期: 2023-09-27 18:36:11
>我在类通信下有一个函数
public int SerialCommunciation()
{
/*Function for opening a serial port with default settings*/
InitialiseSerialPort();
/*This section of code will try to write to the COM port*/
WriteDataToCOM();
/*An event handler */
_serialPort.DataReceived += new SerialDataReceivedEventHandler(_serialPort_DataReceived);
return readData;
}
这里
int readData /*is a global variable*/
_serialPortDataRecieved() 根据从串口读取的数据更新变量 readData
/* Method that will be called when there is data waiting in the buffer*/
private void _serialPort_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
string text = _serialPort.ReadExisting();
int.TryParse(text, out readData);
}
现在当我从另一个类调用这个函数时
valueReadFromCom=Communication.SerialCommunication()
我需要从串行端口读取值,但我得到了 0。当我尝试调试此代码时,我发现控件首先转到语句
return readData;
在函数串行通信中,然后控制才转到函数_serialPort_DataRecieved,函数由事件触发。如何使整个过程同步,这意味着只有在执行函数_serial_DataRecieved后,才应该从函数 serialCommunication 返回 readData。
请注意
,由于串行端口异步工作,因此以下方法不正确。另一方面,无论如何它都可以完成这项工作。
只需添加一个 boolen 属性并在从 SerialCommunication 函数返回之前检查此属性;在接收数据时将此属性设置为 true。
private bool dataReceived = false;
public int SerialCommunciation()
{
/*Function for opening a serial port with default settings*/
InitialiseSerialPort();
/*This section of code will try to write to the COM port*/
WriteDataToCOM();
/*An event handler */
_serialPort.DataReceived += new SerialDataReceivedEventHandler(_serialPort_DataReceived);
while (!dataReceived)
{
Thread.Sleep(1000);
}
return readData;
}
private void _serialPort_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
string text = _serialPort.ReadExisting();
int.TryParse(text, out readData);
_serialPort_DataReceived = true;
}