एक और संभावना यह है कि DispatcherTimer के wpf कार्यान्वयन में एक बग है (मिलीसेकंड और टिक्स के
बीच एक विसंगति है जो सटीक प्रक्रिया निष्पादन समय के आधार पर संभावित
गलतता उत्पन्न करती है), जैसा कि नीचे प्रमाणित है:
http://referencesource.microsoft.com/#WindowsBase
/Base/System/Windows/Threading/DispatcherTimer.cs,143
class DispatcherTimer
{
public TimeSpan Interval
{
set
{
...
_interval = value;
//Notice below bug: ticks1 + milliseconds [Bug1]
_dueTimeInTicks = Environment.TickCount + (int)_interval.TotalMilliseconds;
}
}
}
http://referencesource.microsoft.com/#WindowsBase/Base
/System/Windows/Threading/Dispatcher.cs
class Dispatcher
{
private object UpdateWin32TimerFromDispatcherThread(object unused)
{
...
_dueTimeInTicks = timer._dueTimeInTicks;
SetWin32Timer(_dueTimeInTicks);
}
private void SetWin32Timer(int dueTimeInTicks)
{
...
//Notice below bug: (ticks1 + milliseconds) - ticks2 [Bug2 - almost cancels Bug1, delta is mostly milliseconds not ticks]
int delta = dueTimeInTicks - Environment.TickCount;
SafeNativeMethods.SetTimer(
new HandleRef(this, _window.Value.Handle),
TIMERID_TIMERS,
delta);//<-- [Bug3 - if delta is ticks, it should be divided by TimeSpan.TicksPerMillisecond = 10000]
}
}
http://referencesource.microsoft.com/#WindowsBase/Shared
/MS/Win32/SafeNativeMethodsCLR.cs,505
class SafeNativeMethodsPrivate
{
...
[DllImport(ExternDll.User32, SetLastError = true, ExactSpelling=true, CharSet=System.Runtime.InteropServices.CharSet.Auto)]
public static extern IntPtr SetTimer(HandleRef hWnd, int nIDEvent, int uElapse, NativeMethods.TimerProc lpTimerFunc);
}
http://msdn.microsoft
.com/en-us/पुस्तकालय/विंडोज़/डेस्कटॉप/ms644906% 28v = vs.85%
29.aspx
uElapse [in]
Type: UINT
The time-out value, in milliseconds.//<-- milliseconds were needed eventually