DWORD GetTickCount(VOID);

This function takes no argument. If it succeeds in performing its operation, which it usually does, it provides the number of milliseconds that have elapsed since you started your computer. Just like the VCL's timer control, what you do with the result of this function is up to you and it can be used in various circumstances. For example, computer games and simulations make great use of this function.

After retrieving the value that this function provides, you can display it in a text-based control. Here is an example:

//---------------------------------------------------------------------------
void __fastcall TForm1::btnElapsedClick(TObject *Sender)
{
	unsigned long Elapsed = GetTickCount();
	edtElapsed->Text = IntToStr(Elapsed);
}
//---------------------------------------------------------------------------

1. To start a new application, on the main menu, click File -> New VCL Forms Application - C++Builder
2. Design the form as follows:
    

   Control Alignment Caption Kind Name TGroupBox   Elapsed Time     TLabel   Time this computer...   lblComputerTime TEdit taRightJustify     edtComputerTime TLabel   millisconds     TLabel   Time since this application...   lblApplicationTime TEdit taRightJustify     edtApplicationTime TLabel   millisconds     TTimer         TBitBtn     bkClose

3. Under the Code Editor, click the header tab to access the file
4. In the private section of the form, declare an unsigned integer as follows:
   

   private:
   	unsigned int TimeTheComputerStarted; // User declarations
   public: // User declarations
   	__fastcall TForm1(TComponent* Owner);
   };
   //---------------------------------------------------------------------------

5. Press F12 to display the form
6. Double-click an unoccupied area of the form
7. Implement the event as follows:

   //---------------------------------------------------------------------------
   void __fastcall TForm1::FormCreate(TObject *Sender)
   {
   	TimeTheComputerStarted = GetTickCount();
   }
   //---------------------------------------------------------------------------

8. Press F12 to return to the form
9. On the form, double-click the Timer1 icon to access its OnTimer event
10. Implement the source file as follows:
    

    //---------------------------------------------------------------------------
    void __fastcall TForm1::Timer1Timer(TObject *Sender)
    {
    	unsigned long CurrentTickValue = GetTickCount();
    	unsigned int Difference = CurrentTickValue - TimeTheComputerStarted;
    
    	edtComputerTime->Text = UnicodeString(CurrentTickValue);
    	edtApplicationTime->Text = UnicodeString(Difference);
    }
    //---------------------------------------------------------------------------

11. Press F9 to test the application
     
    
12. After testing the application, close the form and return to your programming environment
13. To make the values easier to read, change the form as follows: Delete both Edit boxes and both milliseconds labele:
     
    
14. Press F12 to access the code
15. Change the code of the OnTimer event as follows:
    

    //---------------------------------------------------------------------------
    void __fastcall TForm1::Timer1Timer(TObject *Sender)
    {
    	unsigned long CurrentTickValue = GetTickCount();
    	unsigned int Difference = CurrentTickValue - TimeTheComputerStarted;
    
    	unsigned int ComputerHours, ComputerMinutes, ComputerSeconds;
    	unsigned int ApplicationHours, ApplicationMinutes, ApplicationSeconds;
    
    	ComputerHours = (CurrentTickValue / (3600 * 999)) % 24;
    	ComputerMinutes = (CurrentTickValue / (60 * 999)) % 60;
    	ComputerSeconds = (CurrentTickValue / 999) % 60;
    	ApplicationHours = (Difference / (3600 * 999)) % 24;
    	ApplicationMinutes = (Difference / (60 * 999)) % 60;
    	ApplicationSeconds = (Difference / 999) % 60;
    
    	UnicodeString ComputerTime, ApplicationTime;
    
    	ComputerTime = UnicodeString(ComputerHours) + L" hours, " +
    	UnicodeString(ComputerMinutes) + L" minutes, and " +
    	UnicodeString(ComputerSeconds) + L" seconds";
    	ApplicationTime = UnicodeString(ApplicationHours) + L" hours, " +
    	UnicodeString(ApplicationMinutes) + L" minutes, and " +
    	UnicodeString(ApplicationSeconds) + L" seconds";
    
    	lblComputerTime->Caption = L"This computer has been ON for "
    	 			   + ComputerTime;
    	lblApplicationTime->Caption = L"This application has been active for "
    				      + ApplicationTime;
    }
    //---------------------------------------------------------------------------

16. Press F9 to test the application
     
    
17. After testing the application, close the form and return to your programming environment