Code:
/ Dotnetfx_Vista_SP2 / Dotnetfx_Vista_SP2 / 8.0.50727.4016 / DEVDIV / depot / DevDiv / releases / Orcas / QFE / wpf / src / Base / System / Windows / Threading / DispatcherTimer.cs / 1 / DispatcherTimer.cs
using System;
using System.Threading;
using System.Windows;
using System.Diagnostics;
using System.Collections.Generic;
namespace System.Windows.Threading
{
///
/// A timer that is integrated into the Dispatcher queues, and will
/// be processed after a given amount of time at a specified priority.
///
public class DispatcherTimer
{
///
/// Creates a timer that uses the current thread's Dispatcher to
/// process the timer event at background priority.
///
public DispatcherTimer() : this(DispatcherPriority.Background) // NOTE: should be Priority Dispatcher.BackgroundPriority
{
}
///
/// Creates a timer that uses the current thread's Dispatcher to
/// process the timer event at the specified priority.
///
///
/// The priority to process the timer at.
///
public DispatcherTimer(DispatcherPriority priority) // NOTE: should be Priority
{
Initialize(Dispatcher.CurrentDispatcher, priority, TimeSpan.FromMilliseconds(0));
}
///
/// Creates a timer that uses the specified Dispatcher to
/// process the timer event at the specified priority.
///
///
/// The priority to process the timer at.
///
///
/// The dispatcher to use to process the timer.
///
public DispatcherTimer(DispatcherPriority priority, Dispatcher dispatcher) // NOTE: should be Priority
{
if(dispatcher == null)
{
throw new ArgumentNullException("dispatcher");
}
Initialize(dispatcher, priority, TimeSpan.FromMilliseconds(0));
}
///
/// Creates a timer that is bound to the specified dispatcher and
/// will be processed at the specified priority, after the
/// specified timeout.
///
///
/// The interval to tick the timer after.
///
///
/// The priority to process the timer at.
///
///
/// The callback to call when the timer ticks.
///
///
/// The dispatcher to use to process the timer.
///
public DispatcherTimer(TimeSpan interval, DispatcherPriority priority, EventHandler callback, Dispatcher dispatcher) // NOTE: should be Priority
{
//
if(callback == null)
{
throw new ArgumentNullException("callback");
}
if(dispatcher == null)
{
throw new ArgumentNullException("dispatcher");
}
if (interval.TotalMilliseconds < 0)
throw new ArgumentOutOfRangeException("interval", SR.Get(SRID.TimeSpanPeriodOutOfRange_TooSmall));
if (interval.TotalMilliseconds > Int32.MaxValue)
throw new ArgumentOutOfRangeException("interval", SR.Get(SRID.TimeSpanPeriodOutOfRange_TooLarge));
Initialize(dispatcher, priority, interval);
Tick += callback;
Start();
}
///
/// Gets the dispatcher this timer is associated with.
///
public Dispatcher Dispatcher
{
get
{
return _dispatcher;
}
}
///
/// Gets or sets whether the timer is running.
///
public bool IsEnabled
{
get
{
return _isEnabled;
}
set
{
lock(_instanceLock)
{
if(!value && _isEnabled)
{
Stop();
}
else if(value && !_isEnabled)
{
Start();
}
}
}
}
///
/// Gets or sets the time between timer ticks.
///
public TimeSpan Interval
{
get
{
return _interval;
}
set
{
bool updateWin32Timer = false;
if (value.TotalMilliseconds < 0)
throw new ArgumentOutOfRangeException("value", SR.Get(SRID.TimeSpanPeriodOutOfRange_TooSmall));
if (value.TotalMilliseconds > Int32.MaxValue)
throw new ArgumentOutOfRangeException("value", SR.Get(SRID.TimeSpanPeriodOutOfRange_TooLarge));
lock(_instanceLock)
{
_interval = value;
if(_isEnabled)
{
_dueTimeInTicks = Environment.TickCount + (int)_interval.TotalMilliseconds;
updateWin32Timer = true;
}
}
if(updateWin32Timer)
{
_dispatcher.UpdateWin32Timer();
}
}
}
///
/// Starts the timer.
///
public void Start()
{
lock(_instanceLock)
{
if(!_isEnabled)
{
_isEnabled = true;
Restart();
}
}
}
///
/// Stops the timer.
///
public void Stop()
{
bool updateWin32Timer = false;
lock(_instanceLock)
{
if(_isEnabled)
{
_isEnabled = false;
updateWin32Timer = true;
// If the operation is in the queue, abort it.
if(_operation != null)
{
_operation.Abort();
_operation = null;
}
}
}
if(updateWin32Timer)
{
_dispatcher.RemoveTimer(this);
}
}
///
/// Occurs when the specified timer interval has elapsed and the
/// timer is enabled.
///
public event EventHandler Tick;
///
/// Any data that the caller wants to pass along with the timer.
///
public object Tag
{
get
{
return _tag;
}
set
{
_tag = value;
}
}
private void Initialize(Dispatcher dispatcher, DispatcherPriority priority, TimeSpan interval)
{
// Note: all callers of this have a "priority" parameter.
Dispatcher.ValidatePriority(priority, "priority");
if(priority == DispatcherPriority.Inactive)
{
throw new ArgumentException(SR.Get(SRID.InvalidPriority), "priority");
}
_dispatcher = dispatcher;
_priority = priority;
_interval = interval;
}
private void Restart()
{
lock(_instanceLock)
{
if (_operation != null)
{
// Timer has already been restarted, e.g. Start was called form the Tick handler.
return;
}
// BeginInvoke a new operation.
_operation = _dispatcher.BeginInvoke(
DispatcherPriority.Inactive,
new DispatcherOperationCallback(FireTick),
null);
_dueTimeInTicks = Environment.TickCount + (int) _interval.TotalMilliseconds;
if (_interval.TotalMilliseconds == 0 && _dispatcher.CheckAccess())
{
// shortcut - just promote the item now
Promote();
}
else
{
_dispatcher.AddTimer(this);
}
}
}
internal void Promote() // called from Dispatcher
{
lock(_instanceLock)
{
// Simply promote the operation to it's desired priority.
if(_operation != null)
{
_operation.Priority = _priority;
}
}
}
private object FireTick(object unused)
{
// The operation has been invoked, so forget about it.
_operation = null;
// The dispatcher thread is calling us because item's priority
// was changed from inactive to something else.
if(Tick != null)
{
Tick(this, EventArgs.Empty);
}
// If we are still enabled, start the timer again.
if(_isEnabled)
{
Restart();
}
return null;
}
// This is the object we use to synchronize access.
private object _instanceLock = new object();
// Note: We cannot BE a dispatcher-affinity object because we can be
// created by a worker thread. We are still associated with a
// dispatcher (where we post the item) but we can be accessed
// by any thread.
private Dispatcher _dispatcher;
private DispatcherPriority _priority; // NOTE: should be Priority
private TimeSpan _interval;
private object _tag;
private DispatcherOperation _operation;
private bool _isEnabled;
internal int _dueTimeInTicks; // used by Dispatcher
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
using System;
using System.Threading;
using System.Windows;
using System.Diagnostics;
using System.Collections.Generic;
namespace System.Windows.Threading
{
///
/// A timer that is integrated into the Dispatcher queues, and will
/// be processed after a given amount of time at a specified priority.
///
public class DispatcherTimer
{
///
/// Creates a timer that uses the current thread's Dispatcher to
/// process the timer event at background priority.
///
public DispatcherTimer() : this(DispatcherPriority.Background) // NOTE: should be Priority Dispatcher.BackgroundPriority
{
}
///
/// Creates a timer that uses the current thread's Dispatcher to
/// process the timer event at the specified priority.
///
///
/// The priority to process the timer at.
///
public DispatcherTimer(DispatcherPriority priority) // NOTE: should be Priority
{
Initialize(Dispatcher.CurrentDispatcher, priority, TimeSpan.FromMilliseconds(0));
}
///
/// Creates a timer that uses the specified Dispatcher to
/// process the timer event at the specified priority.
///
///
/// The priority to process the timer at.
///
///
/// The dispatcher to use to process the timer.
///
public DispatcherTimer(DispatcherPriority priority, Dispatcher dispatcher) // NOTE: should be Priority
{
if(dispatcher == null)
{
throw new ArgumentNullException("dispatcher");
}
Initialize(dispatcher, priority, TimeSpan.FromMilliseconds(0));
}
///
/// Creates a timer that is bound to the specified dispatcher and
/// will be processed at the specified priority, after the
/// specified timeout.
///
///
/// The interval to tick the timer after.
///
///
/// The priority to process the timer at.
///
///
/// The callback to call when the timer ticks.
///
///
/// The dispatcher to use to process the timer.
///
public DispatcherTimer(TimeSpan interval, DispatcherPriority priority, EventHandler callback, Dispatcher dispatcher) // NOTE: should be Priority
{
//
if(callback == null)
{
throw new ArgumentNullException("callback");
}
if(dispatcher == null)
{
throw new ArgumentNullException("dispatcher");
}
if (interval.TotalMilliseconds < 0)
throw new ArgumentOutOfRangeException("interval", SR.Get(SRID.TimeSpanPeriodOutOfRange_TooSmall));
if (interval.TotalMilliseconds > Int32.MaxValue)
throw new ArgumentOutOfRangeException("interval", SR.Get(SRID.TimeSpanPeriodOutOfRange_TooLarge));
Initialize(dispatcher, priority, interval);
Tick += callback;
Start();
}
///
/// Gets the dispatcher this timer is associated with.
///
public Dispatcher Dispatcher
{
get
{
return _dispatcher;
}
}
///
/// Gets or sets whether the timer is running.
///
public bool IsEnabled
{
get
{
return _isEnabled;
}
set
{
lock(_instanceLock)
{
if(!value && _isEnabled)
{
Stop();
}
else if(value && !_isEnabled)
{
Start();
}
}
}
}
///
/// Gets or sets the time between timer ticks.
///
public TimeSpan Interval
{
get
{
return _interval;
}
set
{
bool updateWin32Timer = false;
if (value.TotalMilliseconds < 0)
throw new ArgumentOutOfRangeException("value", SR.Get(SRID.TimeSpanPeriodOutOfRange_TooSmall));
if (value.TotalMilliseconds > Int32.MaxValue)
throw new ArgumentOutOfRangeException("value", SR.Get(SRID.TimeSpanPeriodOutOfRange_TooLarge));
lock(_instanceLock)
{
_interval = value;
if(_isEnabled)
{
_dueTimeInTicks = Environment.TickCount + (int)_interval.TotalMilliseconds;
updateWin32Timer = true;
}
}
if(updateWin32Timer)
{
_dispatcher.UpdateWin32Timer();
}
}
}
///
/// Starts the timer.
///
public void Start()
{
lock(_instanceLock)
{
if(!_isEnabled)
{
_isEnabled = true;
Restart();
}
}
}
///
/// Stops the timer.
///
public void Stop()
{
bool updateWin32Timer = false;
lock(_instanceLock)
{
if(_isEnabled)
{
_isEnabled = false;
updateWin32Timer = true;
// If the operation is in the queue, abort it.
if(_operation != null)
{
_operation.Abort();
_operation = null;
}
}
}
if(updateWin32Timer)
{
_dispatcher.RemoveTimer(this);
}
}
///
/// Occurs when the specified timer interval has elapsed and the
/// timer is enabled.
///
public event EventHandler Tick;
///
/// Any data that the caller wants to pass along with the timer.
///
public object Tag
{
get
{
return _tag;
}
set
{
_tag = value;
}
}
private void Initialize(Dispatcher dispatcher, DispatcherPriority priority, TimeSpan interval)
{
// Note: all callers of this have a "priority" parameter.
Dispatcher.ValidatePriority(priority, "priority");
if(priority == DispatcherPriority.Inactive)
{
throw new ArgumentException(SR.Get(SRID.InvalidPriority), "priority");
}
_dispatcher = dispatcher;
_priority = priority;
_interval = interval;
}
private void Restart()
{
lock(_instanceLock)
{
if (_operation != null)
{
// Timer has already been restarted, e.g. Start was called form the Tick handler.
return;
}
// BeginInvoke a new operation.
_operation = _dispatcher.BeginInvoke(
DispatcherPriority.Inactive,
new DispatcherOperationCallback(FireTick),
null);
_dueTimeInTicks = Environment.TickCount + (int) _interval.TotalMilliseconds;
if (_interval.TotalMilliseconds == 0 && _dispatcher.CheckAccess())
{
// shortcut - just promote the item now
Promote();
}
else
{
_dispatcher.AddTimer(this);
}
}
}
internal void Promote() // called from Dispatcher
{
lock(_instanceLock)
{
// Simply promote the operation to it's desired priority.
if(_operation != null)
{
_operation.Priority = _priority;
}
}
}
private object FireTick(object unused)
{
// The operation has been invoked, so forget about it.
_operation = null;
// The dispatcher thread is calling us because item's priority
// was changed from inactive to something else.
if(Tick != null)
{
Tick(this, EventArgs.Empty);
}
// If we are still enabled, start the timer again.
if(_isEnabled)
{
Restart();
}
return null;
}
// This is the object we use to synchronize access.
private object _instanceLock = new object();
// Note: We cannot BE a dispatcher-affinity object because we can be
// created by a worker thread. We are still associated with a
// dispatcher (where we post the item) but we can be accessed
// by any thread.
private Dispatcher _dispatcher;
private DispatcherPriority _priority; // NOTE: should be Priority
private TimeSpan _interval;
private object _tag;
private DispatcherOperation _operation;
private bool _isEnabled;
internal int _dueTimeInTicks; // used by Dispatcher
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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