1   //this code is helpful if you want to write an app to detect whenever
2   //the system time of you PC has changed.
3   //-----------------------------UNIT1.H-------------------------------------
4   
5   #ifndef Unit1H
6   #define Unit1H
7   //---------------------------------------------------------------------------
8   #include <Classes.hpp>
9   #include <Controls.hpp>
10  #include <StdCtrls.hpp>
11  #include <Forms.hpp>
12  //---------------------------------------------------------------------------
13  class TForm1 : public TForm
14  {
15  __published:	// IDE-managed Components
16          TButton *Button1;
17          void __fastcall Button1Click(TObject *Sender);
18  private:	// User declarations
19  void __fastcall WMTIMECHANGE(TMessage &Message);
20  public:		// User declarations
21          __fastcall TForm1(TComponent* Owner);
22        BEGIN_MESSAGE_MAP
23              VCL_MESSAGE_HANDLER(WM_TIMECHANGE, TMessage,WMTIMECHANGE)
24              END_MESSAGE_MAP(TForm)
25  
26  
27  };
28  //---------------------------------------------------------------------------
29  extern PACKAGE TForm1 *Form1;
30  //---------------------------------------------------------------------------
31  #endif
32  
33  //-----------------------------UNIT1.CPP----------------------------------
34  #include <vcl.h>
35  #pragma hdrstop
36  
37  #include "Unit1.h"
38  //---------------------------------------------------------------------------
39  #pragma package(smart_init)
40  #pragma resource "*.dfm"
41  TForm1 *Form1;
42  //---------------------------------------------------------------------------
43  __fastcall TForm1::TForm1(TComponent* Owner)
44          : TForm(Owner)
45  {
46  }
47  //---------------------------------------------------------------------------
48  
49   void __fastcall TForm1::WMTIMECHANGE(TMessage &Message)
50      {
51    ShowMessage("Time changed");
52  
53      }
54  void __fastcall TForm1::Button1Click(TObject *Sender)
55  {
56  Form1->Close();
57  }