XAML/C++: Does anyone really know what time it is? Timers

Why is it so hard to find a working example on how to use the timer in your C++ app?

So let's take a look at some code:

First you need to change the stdafx.h file, you can simply copy and paste the following into a console c++ app:

 #pragma once

 /*    Tells the system what version the code can run on

 *    actually just refers to another header file: sdkddkver.h */

 #include "targetver.h"

 /*    <stdio.h>

 *    is a file which defines the structures, values, macros, and functions

 *    used by the level 2 I/O ("standard I/O") routines.  It is an ansi standard library */

 #include <stdio.h>

 /*  <tchar.h>

 *    Definitions for generic international functions, mostly defines

 *    which map string/formatted-io/ctype functions to char, wchar_t, or

 *    MBCS versions.  To be used for compatibility between single-byte,

 *    multi-byte and Unicode text models. */

 #include <tchar.h>

 /*    <iostream>

 *    Header for I/O

*/

 #include <iostream>

 /*    <Windows.h>

 *    Master include file for Windows applications.

 *    Interesting reading for sure*/

 #include <Windows.h>

 /*    using namespace std;

 *    The keyword using is used to introduce a name from a namespace into the current declarative region.

 *    using namespace std; means you don't have to write std::cin

 *    on the other hand, a lot of developers do not feel that this is a good practice

 *    your choice, I use it. */

 using namespace std;

For now let's keep with the console app, I don't like it, but it will keep the code a little cleaner, this is a mild modification of the example code at: https://msdn.microsoft.com/en-us/library/windows/desktop/ms687008(v=vs.85).aspx , which doesn't include the stdafx.h file corrected like the above one.

I will be using this or similar to show how to use a timer in a game.

 #include "stdafx.h"

 int main()

     HANDLE hTimer = NULL;

     LARGE_INTEGER largeIntLengthOfTime;

     largeIntLengthOfTime.QuadPart = -50000000LL;

     // Create an unnamed waitable timer.

     hTimer = CreateWaitableTimer(NULL, TRUE, NULL);

     if(NULL == hTimer)

         /* If the CreateWaitableTimer didn't work, then the hTimer will be null

         *  Note that GetLastError is found in the errhandlingapi.h (thank you Captain Obvious) */

         printf("CreateWaitableTimer didn't work (%d)\n", GetLastError());

         return 1;

     printf("Period = 5s...\n");

     /* Wait for a 5s period.  This uses the synchapi.h header file

     *  This is a function see: https://msdn.microsoft.com/en-us/library/windows/desktop/dd405521(v=vs.85).aspx

*/

     if (!SetWaitableTimer(hTimer, &largeIntLengthOfTime, 0, NULL, NULL, 0))

         printf("SetWaitableTimer failed (%d)\n", GetLastError());

         return 2;

     /* Wait for the timer to signal, the INFINITE keyword indicates that the timer must signal for the

*/

     if (WaitForSingleObject(hTimer, INFINITE) != WAIT_OBJECT_0)

         printf("WaitForSingleObject failed (%d)\n", GetLastError());

     else printf("The timer has signaled the one time it will.\n");

     return 0;

Comments

Anonymous
May 28, 2013
What about using the DispatcherTimer Class? msdn.microsoft.com/.../windows.ui.xaml.dispatchertimer
Anonymous
May 29, 2013
Darn you Jim Boddie, but there is an issue with that one, mainly I didn't cover it. I just hate it when a reader comes up with a great idea. Good work, keep reading.