WndProcMouseMoveOnCaptionBar.cpp

#include <vcl.h>
#pragma hdrstop

#include "WndProcMouseMoveOnCaptionBar.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
   Color = clRed;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::WndProc( Messages::TMessage &Message )
{
   //Detect when the mouse moves on the caption bar of Form1 
   //

   if( (Message.Msg == WM_NCMOUSEMOVE) &&
       (Message.WParam == HTCAPTION) )
   {
       ShowMessage("Windows Message: WM_NCMOUSEMOVE \n\
                    WParam: HTCAPTION");
   }
   else
   {
       TForm::WndProc( Message );
   }
}

WndProcMouseMoveOnCaptionBar.h

#ifndef Unit1H
#define Unit1H
//---------------------------------------------------------------------------
#include <Classes.hpp>
#include <Controls.hpp>
#include <StdCtrls.hpp>
#include <sForms.hpp>
//---------------------------------------------------------------------------
class TForm1 : public TForm
{
__published:	// IDE-managed Components
private:	// User declarations
public:		// User declarations
        __fastcall TForm1(TComponent* Owner);
        void __fastcall WndProc( Messages::TMessage &Message );
};
//---------------------------------------------------------------------------
extern PACKAGE TForm1 *Form1;
//---------------------------------------------------------------------------
#endif