如何处理DataReceived

Question

请参阅下面的代码，我试图返回到注册端口的DataReceived事件的方法。 基本上，如果我在读取超时之前从端口接收数据。 我将返回注册DataReceived事件和degister的位置，然后继续进行处理。 我正在尝试使用while循环。 但不确定是否准确，这是必须执行的方法，或者是否有其他方法可以执行此操作。

public class CommClass{
private static byte[] portReturn = null;

private void setUpDevice()
{
    byte[] command = { 0x11,0X51 };
    try
    {
        port.DataReceived += new SerialDataReceivedEventHandler(serialPortDataReceived);
        port.Write(command, 0, command.Length);
        while (portReturn == null) { } //Not sure if this will work. If I receive data before times out I do not want to wait in the loop.
        port.DataReceived -= serialPortDataReceived;
    }
    catch(Exception ex)
    {
        //to do
    }
}


private void serialPortDataReceived(object sender, SerialDataReceivedEventArgs e)
{
    var servicePort = (SerialPort)sender;
    portReturn = servicePort.ReadByte();
    return;
}
}

Answer 1

您的代码将在技术上有效； 但是，当您等待数据进入时，while循环将使CPU最大化，这不是您想要的。 我建议在此处使用ManualResetEvent ，让您等待以CPU友好的方式接收数据。 您可以在这里阅读更多有关它们的信息

public class CommClass
{
    private static byte[] portReturn = null;

    // ManualResetEvents are great for signaling events across threads
    private static ManualResetEvent dataReceivedEvent = new ManualResetEvent(false);

    private void setUpDevice()
    {
        byte[] command = { 0x11,0X51 };
        try
        {
            port.DataReceived += new SerialDataReceivedEventHandler(serialPortDataReceived);
            port.Write(command, 0, command.Length);

            // Wait for the event to be set without spinning in a loop.
            // Can also specify a timeout period to wait in case the data never comes.
            dataReceivedEvent.WaitOne();

            // Reset the event so that you can use it again later if necessary
            dataReceivedEvent.Reset();

            port.DataReceived -= serialPortDataReceived;
        }
        catch(Exception ex)
        {
            //to do
        }
    }


    private void serialPortDataReceived(object sender, SerialDataReceivedEventArgs e)
    {
        var servicePort = (SerialPort)sender;
        portReturn = servicePort.ReadByte();

        // Set the event to let the main thread know you have received data
        dataReceivedEvent.Set();
    }
}