FeliceM
Reputation: 4199
Passing variables to timer event in a class
I have a method in a class that receives and returns multiple parameters from/to Form1. I need to use a timed event to execute some code using those parameters. I have arranged this simplified code to show the dynamic:
class Motor
{
public static System.Timers.Timer _timer;
int valReg = 30;
public void PID(decimal _actualSpeed, Decimal _speedRequest, out Decimal _pwmAuto, out decimal _preValReg)
{
_timer = new System.Timers.Timer();
_timer.Interval = (3000);
_timer.Elapsed += new System.Timers.ElapsedEventHandler(_timerAutoset);
_timer.Enabled = true;
// {....}
_pwmAuto = valReg;
_preValReg = valReg - 1;
}
static void _timerAutoset(object sender, System.Timers.ElapsedEventArgs e)
{
/* here I need to work with:
_actualSpeed
_speedRequest
_pwmAuto
_preValReg
and send back the last two variables
*/
}
}
This is how I pass and receive the variables from Form1 button :
private void button4_Click(object sender, EventArgs e)
{
// some code ................
Motor mtr = new Motor();
mtr.PID(speedRequest, actualSpeed, out pwmAuto, out xxx);
//..more code
How can I pass/get back those parameters to/from _timerAutoset event?
Upvotes: 7
Views: 27178
Answers (7)
Barun
Reputation: 1915
I just coded this class. I wish it helpful to others.
private class CustomTimer : IDisposable
{
private int duration = 1000;
private Action<object> tick;
private object obj;
private Thread thread;
private bool start = false;
public CustomTimer(int duration, Action<object> tick)
{
this.duration = duration;
this.tick = tick;
}
public void Start(object obj)
{
this.obj = obj;
start = true;
if (thread == null)
{
keepRunning = true;
thread = new Thread(ThreadMethod);
thread.Start();
}
else
{
if (thread.ThreadState == ThreadState.WaitSleepJoin)
thread.Interrupt();
}
}
public void Stop()
{
if (!start)
return;
start = false;
if (thread.ThreadState == ThreadState.WaitSleepJoin)
thread.Interrupt();
}
public bool IsStopped
{
get { return !start; }
}
private bool keepRunning = false;
private void ThreadMethod()
{
while (keepRunning)
{
if (start)
{
try { Thread.Sleep(duration); } catch { }
if (start && keepRunning)
tick(this.obj);
}
else if(keepRunning)
{
try { Thread.Sleep(int.MaxValue); } catch { }
}
}
}
public void Dispose()
{
this.keepRunning = false;
this.start = false;
if (thread.ThreadState == ThreadState.WaitSleepJoin)
thread.Interrupt();
if (thread.ThreadState == ThreadState.WaitSleepJoin)
thread.Interrupt();
}
}
Upvotes: 0
Olli
Reputation: 375
I'm using a Backgroundworker styled class called "ScheduledWorker" which executes a recurring operation on a separate thread and returns to the main thread after each execution of this background operation.
For data exchange an object variable can be passed to the background operation when starting the ScheduledWorker and can also be changed while the ScheduledWorker is running. Inside the background procedure this object can be called via DoScheduledWorkEventArgs.Argument. The time when the DoWork event was raised can be called via DoScheduledWorkEventArgs.SignalTime property. The way ScheduledWorker reports result and progress of the background operation to the main thread is the same as the BackgroundWorker class.
using System;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Runtime.Versioning;
using System.Security;
using System.Security.Permissions;
using System.Threading;
namespace ScheduledWorker
{
/// <summary>
/// Executes a recurring operation on a separate thread.
/// </summary>
[DefaultEvent("DoWork")]
[HostProtection(SharedState = true)]
public partial class ScheduledWorker : Component, ISupportInitialize
{
private bool enabled;
private bool delayedEnable;
private bool initializing;
private bool disposed;
private readonly ManualResetEvent doNotDisposeWaitHandle = new ManualResetEvent(false);
private int disposeWaitMSec;
private bool cancellationPending;
private bool isRunning;
private bool isOccupied;
private bool isWorking;
private object argument;
private readonly object statusChangeLockObject = new object();
private readonly object doWorkKey = new object();
private readonly object runWorkerCompletedKey = new object();
private readonly object progressChangedKey = new object();
private readonly EventHandler<DoScheduledWorkEventArgs> workHandler;
private readonly SendOrPostCallback completedCallback;
private readonly SendOrPostCallback progressCallback;
private AsyncOperation mainThreadOperation;
private Timer timer;
private double interval;
/// <summary>
/// Initializes a new instance of the ScheduledWorker class and sets the <see cref="ScheduledWorker.Interval"/> property to 100 milliseconds.
/// </summary>
public ScheduledWorker() : this(100, -1) { }
/// <summary>
/// Initializes a new instance of the ScheduledWorker class, and sets the <see cref="ScheduledWorker.Interval"/> property to the specified number of milliseconds.
/// </summary>
/// <param name="interval">The time, in milliseconds, between events. The value must be greater than zero and less than or equal to <see cref="int.MaxValue"/>."/></param>
public ScheduledWorker(double interval, int disposeWaitMSec) : base()
{
this.interval = interval;
this.disposeWaitMSec = disposeWaitMSec;
completedCallback = new SendOrPostCallback(AsynOperationCompleted);
progressCallback = new SendOrPostCallback(ProgressReporter);
initializing = false;
delayedEnable = false;
workHandler = new EventHandler<DoScheduledWorkEventArgs>(WorkerThreadStart);
}
/// <summary>
/// Occurs when <see cref="ScheduledWorker.RunWorkerAsync"/> or <see cref="ScheduledWorker.RunWorkerAsync(object)"/> are called.
/// </summary>
public event EventHandler<DoScheduledWorkEventArgs> DoWork
{
add
{
Events.AddHandler(doWorkKey, value);
}
remove
{
Events.RemoveHandler(doWorkKey, value);
}
}
/// <summary>
/// Occurs when the background operation has completed, has been canceled, or has raised an exception.
/// </summary>
public event EventHandler<RunWorkerCompletedEventArgs> RunWorkerCompleted
{
add
{
Events.AddHandler(runWorkerCompletedKey, value);
}
remove
{
Events.RemoveHandler(runWorkerCompletedKey, value);
}
}
/// <summary>
/// Occurs when <see cref="ScheduledWorker.ReportProgress(int)"/> or <see cref="ScheduledWorker.ReportProgress(int, object)"/> are called.
/// </summary>
public event EventHandler<ProgressChangedEventArgs> ProgressChanged
{
add
{
Events.AddHandler(progressChangedKey, value);
}
remove
{
Events.RemoveHandler(progressChangedKey, value);
}
}
/// <summary>
/// Starts raising the <see cref="ScheduledWorker.DoWork"/> event by setting Enabled to true.
/// </summary>
public void RunWorkerAsync()
{
RunWorkerAsync(null);
}
/// <summary>
/// Starts raising the <see cref="ScheduledWorker.DoWork"/> event by setting Enabled to true.
/// </summary>
/// <param name="argument">A parameter for use by the background operation to be executed in the <see cref="ScheduledWorker.DoWork"/> event handler.</param>
public void RunWorkerAsync(object argument)
{
Argument = argument;
Enabled = true;
}
/// <summary>
/// Stops raising the <see cref="ScheduledWorker.DoWork"/> event by setting Enabled to false.
/// </summary>
public void Stop()
{
Enabled = false;
}
/// <summary>
/// Gets or sets a value indicating whether the <see cref="ScheduledWorker.DoWork"/> event should be raised.
/// </summary>
[Category("Behavior")]
public bool Enabled
{
get
{
lock (statusChangeLockObject)
{
return enabled;
}
}
set
{
if (DesignMode)
{
delayedEnable = value;
enabled = value;
}
else if (initializing)
{
delayedEnable = value;
}
else if (enabled != value)
{
lock (statusChangeLockObject)
{
if (!value)
{
if (timer != null)
{
timer.Dispose();
timer = null;
}
enabled = false;
if (!isWorking)
{
if (!isOccupied)
{
isRunning = false;
}
SetMainThreadOperationCompleted();
}
}
else
{
enabled = true;
if (timer == null && !isRunning)
{
if (disposed)
{
throw new ObjectDisposedException(GetType().Name);
}
else
{
int roundedInterval = Convert.ToInt32(Math.Ceiling(interval));
isRunning = true;
isOccupied = false;
isWorking = false;
cancellationPending = false;
SetMainThreadOperationCompleted();
mainThreadOperation = AsyncOperationManager.CreateOperation(null);
timer = new Timer(MyTimerCallback, null, roundedInterval, roundedInterval);
}
}
else if (isRunning)
{
throw new InvalidOperationException("ScheduledWorker is busy.");
}
else
{
UpdateTimer();
}
}
}
}
}
}
/// <summary>
/// Gets or sets the interval, expressed in milliseconds, at which to raise the <see cref="ScheduledWorker.DoWork"/> event.
/// It can be changed while the ScheduledWorker is running.
/// </summary>
[Category("Behavior"), DefaultValue(100d), SettingsBindable(true)]
public double Interval
{
get
{
return interval;
}
set
{
if (value <= 0)
{
throw new ArgumentException("Minimum interval is 1.");
}
else
{
interval = value;
if (timer != null)
{
UpdateTimer();
}
}
}
}
/// <summary>
/// Gets or sets a value indicating whether the ScheuledWorker can report progress updates.
/// </summary>
[DefaultValue(false)]
public bool WorkerReportsProgress { get; set; }
/// <summary>
/// Raises the ProgressChanged event.
/// </summary>
/// <param name="percentProgress">The percentage, from 0 to 100, of the background operation that is complete.</param>
public void ReportProgress(int percentProgress)
{
ReportProgress(percentProgress, null);
}
/// <summary>
/// Raises the ProgressChanged event.
/// </summary>
/// <param name="percentProgress">The percentage, from 0 to 100, of the background operation that is complete.</param>
/// <param name="userState">The state object passed to <see cref="ScheduledWorker.RunWorkerAsync(object)"/>.</param>
public void ReportProgress(int percentProgress, object userState)
{
if (!WorkerReportsProgress)
{
throw new InvalidOperationException("This ScheduledWorker does not support reporting progress.");
}
else
{
mainThreadOperation.Post(progressCallback, new ProgressChangedEventArgs(percentProgress, userState));
}
}
/// <summary>
/// Gets or sets a value indicating whether the ScheduledWorker supports asynchronous cancellation.
/// </summary>
[DefaultValue(false)]
public bool WorkerSupportsCancellation { get; set; }
/// <summary>
/// Gets a value indicating whether the application has requested cancellation of a background operation.
/// </summary>
[Browsable(false)]
public bool CancellationPending
{
get
{
lock (statusChangeLockObject)
{
return cancellationPending;
}
}
}
/// <summary>
/// Requests cancellation of a pending background operation.
/// </summary>
public void CancelAsync()
{
if (!WorkerSupportsCancellation)
{
throw new InvalidOperationException("This ScheduledWorker does not support cancellation.");
}
else
{
lock (statusChangeLockObject)
{
cancellationPending = true;
Stop();
}
}
}
/// <summary>
/// Gets a value indicating whether the ScheduledWorker is running an asynchronous operation. This is the case until the SchedeuledWorker has been stopped (<see cref="ScheduledWorker.Enabled"/> = false)
/// and the last <see cref="ScheduledWorker.DoWork"/> event has completed.
/// </summary>
[Browsable(false)]
public bool IsBusy
{
get
{
lock (statusChangeLockObject)
{
return isRunning;
}
}
}
/// <summary>
/// A parameter for use by the background operation to be executed in the <see cref="ScheduledWorker.DoWork"/> event handler.
/// It can be changed while the ScheduledWorker is running.
/// </summary>
[Browsable(false)]
public object Argument
{
get
{
return Interlocked.Exchange(ref argument, argument);
}
set
{
Interlocked.Exchange(ref argument, value);
}
}
/// <summary>
/// Begins the run-time initialization of a ScheduledWorker that is used on a form or by another component.
/// </summary>
public void BeginInit()
{
Close();
initializing = true;
}
/// <summary>
/// Ends the run-time initialization of a ScheduledWorker that is used on a form or by another component.
/// </summary>
public void EndInit()
{
initializing = false;
enabled = delayedEnable;
}
private void MyTimerCallback(object state)
{
lock (statusChangeLockObject)
{
try
{
if (enabled && !isOccupied)
{
doNotDisposeWaitHandle.Reset();
isOccupied = true;
isWorking = true;
FILE_TIME fileTime = new FILE_TIME();
SafeNativeMethods.GetSystemTimeAsFileTime(ref fileTime);
workHandler.BeginInvoke(this,
new DoScheduledWorkEventArgs(Argument,
DateTime.FromFileTime((long)((((ulong)fileTime.ftTimeHigh) << 32) | (((ulong)fileTime.ftTimeLow) & 0xffffffff)))),
null,
null);
}
}
catch { }
}
}
private void WorkerThreadStart(object sender, DoScheduledWorkEventArgs args)
{
Exception Error = null;
try
{
if (CancellationPending)
{
args.Cancel = true;
}
else
{
OnDoWork(args);
}
if (args.Cancel)
{
args.Result = null;
cancellationPending = true;
}
}
catch (Exception ex)
{
Error = ex;
args.Result = null;
}
finally
{
mainThreadOperation.Post(completedCallback, new RunWorkerCompletedEventArgs(args.Result, Error, args.Cancel));
doNotDisposeWaitHandle.Set();
}
}
protected void OnDoWork(DoScheduledWorkEventArgs args)
{
((EventHandler<DoScheduledWorkEventArgs>)Events[doWorkKey])?.Invoke(this, args);
}
private void AsynOperationCompleted(object args)
{
lock (statusChangeLockObject)
{
isWorking = false;
if (!enabled)
{
isRunning = false;
SetMainThreadOperationCompleted();
}
}
OnRunWorkerCompleted((RunWorkerCompletedEventArgs)args);
lock (statusChangeLockObject)
{
isOccupied = false;
if (!enabled)
{
isRunning = false;
SetMainThreadOperationCompleted();
}
}
}
protected void OnRunWorkerCompleted(RunWorkerCompletedEventArgs args)
{
((EventHandler<RunWorkerCompletedEventArgs>)Events[runWorkerCompletedKey])?.Invoke(this, args);
}
private void SetMainThreadOperationCompleted()
{
if (mainThreadOperation != null)
{
mainThreadOperation.OperationCompleted();
mainThreadOperation = null;
}
}
private void ProgressReporter(object arg)
{
OnProgressChanged((ProgressChangedEventArgs)arg);
}
protected void OnProgressChanged(ProgressChangedEventArgs args)
{
((EventHandler<ProgressChangedEventArgs>)Events[progressChangedKey])?.Invoke(this, args);
}
private void UpdateTimer()
{
int roundedInterval = Convert.ToInt32(Math.Ceiling(interval));
timer.Change(roundedInterval, roundedInterval);
}
protected override void Dispose(bool disposing)
{
disposed = true;
Close();
base.Dispose(disposing);
}
public void Close()
{
if (timer != null)
{
timer.Change(Timeout.Infinite, Timeout.Infinite);
using (ManualResetEvent disposeWaitHandle = new ManualResetEvent(false))
{
if (timer.Dispose(disposeWaitHandle))
{
disposeWaitHandle.WaitOne(disposeWaitMSec, false);
}
timer = null;
}
}
initializing = false;
delayedEnable = false;
enabled = false;
doNotDisposeWaitHandle.WaitOne(disposeWaitMSec, false);
doNotDisposeWaitHandle.Close();
SetMainThreadOperationCompleted();
}
[StructLayout(LayoutKind.Sequential)]
internal struct FILE_TIME
{
internal int ftTimeLow;
internal int ftTimeHigh;
}
private sealed class SafeNativeMethods
{
[ResourceExposure(ResourceScope.None)]
[DllImport("Kernel32"), SuppressUnmanagedCodeSecurityAttribute()]
internal static extern void GetSystemTimeAsFileTime(ref FILE_TIME lpSystemTimeAsFileTime);
}
}
/// <summary>
/// Provides data for the <see cref="ScheduledWorker.DoWork"/> event.
/// </summary>
public sealed class DoScheduledWorkEventArgs : DoWorkEventArgs
{
internal DoScheduledWorkEventArgs(object arg, DateTime signalTime) : base(arg)
{
SignalTime = signalTime;
}
/// <summary>
/// Gets the date/time when the <see cref="ScheduledWorker.DoWork"/> event was raised.
/// </summary>
public DateTime SignalTime { get; }
}
}
Upvotes: 1
user1360355
Reputation:
private void StartTimerForDeleteMessage(UC_ChatReceiveMessageControl ucChatReceiveMessageControl)
{
try
{
System.Timers.Timer aTimer = new System.Timers.Timer();
aTimer.Elapsed += (sender, e) => MyElapsedMethod(sender, e, ucChatReceiveMessageControl);
aTimer.Interval = 1000;
aTimer.Enabled = true;
}
catch (Exception ex)
{
Helper.WriteToLogFile("SetMessageBodyContentAfterAcknoledged ex::" + ex.Message, LoggingLevel.Errors);
}
}
static void MyElapsedMethod(object sender, ElapsedEventArgs e, UC_ChatReceiveMessageControl ucChatReceiveMessageControl)
{
try
{
}
catch (Exception ex)
{
Helper.WriteToLogFile("SetMessageBodyContentAfterAcknoledged ex::" + ex.Message, LoggingLevel.Errors);
}
}
Upvotes: 0
Andrew Shepherd
Reputation: 45252
I tend to solve this problem using anonymous delegates.
public void PID(decimal _actualSpeed, Decimal _speedRequest, out Decimal _pwmAuto, out decimal _preValReg)
{
_pwmAuto = valReg;
_preValReg = valReg - 1;
// Because we cannot use [out] variables inside the anonymous degegates,
// we make a value copy
Decimal pwmAutoLocal = _pwmAuto;
Decimal preValRegLocal = _preValReg;
_timer = new System.Timers.Timer();
_timer.Interval = (3000);
_timer.Elapsed += (sender, e) => { HandleTimerElapsed(_actualSpeed, _speedRequst, pwmAutoLocal, preValRegLocal); };
_timer.Enabled = true;
// {....}
}
static void HandleTimerElapsed(Decimal actualSpeed, Decimal speedRequst, Decimal pwmAuto, Decimal preValReg)
{
// (...)
}
(You have to be mindful when the delegate accesses local variables from the enclosing block. Double-check the code to ensure the values stored in those variables will not change between the assignment of the event handler and the invocation of this handler).
Upvotes: 14
Ali
Reputation: 1409
It seems these parameters are coming from somewhere else. One approach could be to pass a callback via delegate and use it to get the updated values from.
Another approach will be to make a class and pass it to Motor's constructor and use its reference in the _timerAutoset to get the updated values.
Using Delegates:
class Motor
{
public static System.Timers.Timer _timer;
int valReg = 30;
public delegate TimerParam ParameterizedTimerDelegate();
public static ParameterizedTimerDelegate TimerCallback { get; set; }
public void PID()
{
_timer = new System.Timers.Timer();
_timer.Interval = (3000);
_timer.Elapsed += new System.Timers.ElapsedEventHandler(_timerAutoset);
_timer.Enabled = true;
// {....}
//Param.PwmAuto = valReg;
//Param.PreValReg = valReg - 1;
}
static void _timerAutoset(object sender, System.Timers.ElapsedEventArgs e)
{
TimerParam param = TimerCallback();
/* here you can use:
Param.ActualSpeed
Param.SpeedRequest
Param.PwmAuto
Param.PreValReg
*/
}
}
Using a shared instance:
class TimerParam
{
public decimal ActualSpeed { get; set; }
public decimal SpeedRequest { get; set; }
public Decimal PwmAuto { get; set; }
public decimal PreValReg { get; set; }
}
class Motor
{
public static System.Timers.Timer _timer;
int valReg = 30;
public TimerParam Param { get; set; }
public void PID(TimerParam param)
{
Param = param;
_timer = new System.Timers.Timer();
_timer.Interval = (3000);
_timer.Elapsed += new System.Timers.ElapsedEventHandler(_timerAutoset);
_timer.Enabled = true;
// {....}
Param.PwmAuto = valReg;
Param.PreValReg = valReg - 1;
}
static void _timerAutoset(object sender, System.Timers.ElapsedEventArgs e)
{
/* here you can use:
Param.ActualSpeed
Param.SpeedRequest
Param.PwmAuto
Param.PreValReg
*/
}
}
You can then update the instance of TimerParam that you passed to the Motor class and timer will always get the updated values.
Upvotes: 2
Rahul
Reputation: 438
you could try using lambda expression for inserting additional arguement..
_timer.Elapsed += (sender, e) => _timerAutoset(sender, e, _actualSpeed,_speedRequest);
your method be like
static void _timerAutoset(object sender, System.Timers.ElapsedEventArgs e,decimal speed,decimal speedRequest)
Upvotes: 1
user2160696
Reputation: 709
You just could initialize them in your class, so all methods could access them...
Upvotes: 0
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