《windows核心程式設計》筆記（四）

定時器示例：

#include <tchar.h>

// The caption of our message box

TCHAR g_szCaption[] = TEXT("Timed Message Box");

// How many seconds we'll display the message box

int g_nSecLeft = 0;

// This is STATIC window control ID for a message box

#define ID_MSGBOX_STATIC_TEXT    0x0000ffff

//控件得值為即xFFFF

VOID WINAPI MsgBoxTimeout(PVOID pvContext, BOOLEAN fTimeout) 

{

   // NOTE: Due to a thread race condition, it is possible (but very unlikely)

   // that the message box will not be created when we get here.

   HWND hwnd = FindWindow(NULL, g_szCaption);

   if (hwnd != NULL) 

   {

      // The window does exist; update the time remaining.

      TCHAR sz[100];

      wsprintf(sz, TEXT("You have %d seconds to respond"), g_nSecLeft--);

      SetDlgItemText(hwnd, ID_MSGBOX_STATIC_TEXT, sz);

      if (g_nSecLeft == 0) 

      {

         // The time is up; force the message box to exit.

         EndDialog(hwnd, IDOK);

      }

   } 

   else 

      // The window does not exist yet; do nothing this time.

      // We'll try again in another second.

   }

}

int WINAPI _tWinMain(HINSTANCE hinstExe, HINSTANCE, PTSTR pszCmdLine, int) 

   chWindows9xNotAllowed();

   // How many seconds we'll give the user to respond

   g_nSecLeft = 10;

   // Create a multishot 1 second timer that begins firing after 1 second.

   HANDLE hTimerQTimer;

   CreateTimerQueueTimer(&hTimerQTimer, NULL, MsgBoxTimeout, NULL, 1000, 1000, 0);

   // Display the message box

   MessageBox(NULL, TEXT("You have 10 seconds to respond"), g_szCaption, MB_OK);

   // Cancel the timer & delete the timer queue

   DeleteTimerQueueTimer(NULL, hTimerQTimer, NULL);

   // Let us know if the user responded or if we timed-out.

   MessageBox(NULL, (g_nSecLeft == 0) ? TEXT("Timeout") : TEXT("User responded"), TEXT("Result"), MB_OK);

   return(0);

本文轉自Phinecos(洞庭散人)部落格園部落格，原文連結：http://www.cnblogs.com/phinecos/archive/2008/06/09/1216331.html，如需轉載請自行聯系原作者