c# - SerialPort.Open() --IOException -- "The parameter is incorrect."

Question

我编写了以下代码来在 MainForm 加载时配置串口。在第一次运行时，它会在端口打开时给出 IOException，说明参数不正确。但是当我重新启动应用程序时它工作正常。只有在启动计算机后第一次运行应用程序时才会出现异常，然后在下次重新启动计算机之前正常运行。

private void Main_Load(object sender, EventArgs e)
{
    this.serialPort1.PortName = "COM3";
    this.serialPort1.BaudRate = 9600;
    this.serialPort1.DataBits = 8;
    this.serialPort1.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(serialPort1_DataReceived);

    this.serialPort1.Open(); //Exception comes here
    this.serialPort1.WriteLine("AT#cid=1" + System.Environment.NewLine);

}

异常详情:

System.IO.IOException was unhandled by user code

Message="The parameter is incorrect.\r\n" Source="System"

StackTrace: at System.IO.Ports.InternalResources.WinIOError(Int32 errorCode, String str) at System.IO.Ports.InternalResources.WinIOError() at System.IO.Ports.SerialStream.set_RtsEnable(Boolean value) at System.IO.Ports.SerialStream..ctor(String portName, Int32 baudRate, Parity parity, Int32 dataBits, StopBits stopBits, Int32 readTimeout, Int32 writeTimeout, Handshake handshake, Boolean dtrEnable, Boolean rtsEnable, Boolean discardNull, Byte parityReplace) at System.IO.Ports.SerialPort.Open() at JKamdar.Main.Main_Load(Object sender, EventArgs e) in D:\Project\JKamdar\JKamdar\Main.cs:line 264 at System.Windows.Forms.Form.OnLoad(EventArgs e) at System.Windows.Forms.Form.OnCreateControl() at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible) at System.Windows.Forms.Control.CreateControl() at System.Windows.Forms.Control.WmShowWindow(Message& m) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ScrollableControl.WndProc(Message& m) at System.Windows.Forms.ContainerControl.WndProc(Message& m) at System.Windows.Forms.Form.WmShowWindow(Message& m) at System.Windows.Forms.Form.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) InnerException:

Answer 1

请尝试使用this.serialPort1.RtsEnable = true

根据异常的堆栈跟踪建议

at System.IO.Ports.SerialStream.set_RtsEnable(Boolean value)
at System.IO.Ports.SerialStream..ctor(String portName, Int32 baudRate, Parity parity, Int32 dataBits, StopBits stopBits, Int32 readTimeout, Int32 writeTimeout, Handshake handshake, Boolean dtrEnable, Boolean rtsEnable, Boolean discardNull, Byte parityReplace)
at System.IO.Ports.SerialPort.Open()