Call Function from a timer-CodePudding

I am trying to call a function as per below tyo determine a pressure value but the timer does not have access to the object 'device'. What is the easiest way to fix this ? Note everything in the button function works perfect. Returns the pressure, serial number etc.

private void Button_Start_Logging_FMS_Data_Click(object sender, EventArgs e)
        {
            try
            {
                
                var devices = PX409Usbh.DetectDevices().ToList();
                var device = devices[0];

                if (devices.Count == 0)
                {
                    MessageBox.Show("no devices found. Make sure the pressure sensor is connected");
                    return;
                }

                // Initialize each sensor so we can view the configuration and range.
                foreach (var d in devices)
                {
                    d.Initialize();
                }

                String Serial_Number = device.SerialNumber;
                String Unit_Measurement = device.Units;
                double Raw_External_Pressure = device.ReadPressure();

                                
                // Start Timer to Capture Data
                System.Timers.Timer aTimer = new System.Timers.Timer();
                aTimer.Elapsed  = new ElapsedEventHandler(OnTimedEvent);
                aTimer.Interval = 1000;
                aTimer.Enabled = true;

            }
            catch (Exception ex)
            {
                // If exception happens, it will be returned here
                Logging.Write_To_Log_File("Error", MethodBase.GetCurrentMethod().Name, "", "", ex.ToString(), "", "", "", 2);

            }

        }



        // Specify what you want to happen when the Elapsed event is raised.
        private void OnTimedEvent(object source, ElapsedEventArgs e)
    {
        double Raw_External_Pressure = device.ReadPressure();
    }

CodePudding user response：

Maybe use System.Threading.Timers.Timer which lets you pass a state object to the callback method (reference) specified as an object containing information to be used by the callback method.

CodePudding user response：

You could use a lambda instead which basically just packages up the arguments you have (the sender and args) and appends your device to the event handler method call.

private void Button_Start_Logging_FMS_Data_Click(object sender, EventArgs e)
{
    // The start of your method here.
    aTimer.Elapsed  = (sender, args) => ElapsedEventHandler(sender, args, device);
    // The end of your method here.
}

private void ElapsedEventHandler(object sender, ElapsedEventArgs e, Device d)
{
    // Do magical things with the Device here.
}

If you don't intend on doing anything with the Timer event args, you can simplify to this:

private void Button_Start_Logging_FMS_Data_Click(object sender, EventArgs e)
{
    // The start of your method here.
    aTimer.Elapsed  = (sender, args) => ElapsedEventHandler(device);
    // The end of your method here.
}

private void ElapsedEventHandler(Device d)
{
    // Do magical things with the Device here.
}