C＃Winforms，从numericupdown存储值

Question

I have a serialport dataRecived event with 2 methods inside it. The LogFile is loging data and drawSetpoint is drawing a graph.

public void serialPort1_DataRecived  (object sender, SerialDataReceivedEventArgs e)
        {

            DateTime time = DateTime.Now;
            string Rdata = serialPort1.ReadLine();
            LogFile(Rdata, (int)numericSetpoint.Value);
            drawSetpoint(time,numericSetpoint.Value.ToString());


        }

Both methods take the second argument from a numericUpDown control which looks like this

public void numericSetpoint_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == 13) 
            {

                if (serialPort1.IsOpen) 
                {
                    int setpoint = (int)numericSetpoint.Value;
                    //send to serial port .....                    
                }

The problem is both methods in my data recived event read digits as I type them. For example, if I type 150, LogFile will show 1,15,150 and the draw function will start drawing 1,15,150. I would like both functions to take the value from the numericSetpoint control after the enter key is pressed so i get the whole value. How could I do that ?

Answer 1

You are using the KeyPress event. Instead consider using the ValueChanged event which only fires when enter is pressed or the user leaves the control https://msdn.microsoft.com/en-us/library/system.windows.forms.numericupdown.valuechanged%28v=vs.110%29.aspx

Answer 2

It sounds like your data rx event is firing while your typing. I would try filling a buffer in your data rx event and hold off on any logging or plotting until you've sent your data. There are bunch of "safe" ways to do this but the core logic is as follows:

byte[] buffer = new byte[MAX_BUFFER];
private volatile bool _ready = false;
private Object _lock = new Object();

public void serialPort1_DataRecived  (object sender, SerialDataReceivedEventArgs e)
{

    DateTime time = DateTime.Now;

    // Either read as bytes or convert string to bytes, add to your buffer
    // string Rdata = serialPort1.ReadLine();

    lock(_lock )
    {
        if(_ready)
        {
            _ready = false;
            var myData = your buffer as string
            // clear buffer
            LogFile(myData, (int)numericSetpoint.Value);
            drawSetpoint(time,numericSetpoint.Value.ToString());
        }
    }

}

...

public void numericSetpoint_KeyPress(object sender, KeyPressEventArgs e)
{
    if (e.KeyChar == 13) 
    {

        if (serialPort1.IsOpen) 
        {
            int setpoint = (int)numericSetpoint.Value;
            //send to serial port .....     
            lock(_lock ) { _ready = true; }               
        }
    }
}