texttransformer.jpg

This article can be obsolete: Actual documentation online

Message handler


Message handlers are methods that implement responses to dynamically dispatched messages. Delphi’s VCL uses message handlers to respond to Windows messages.

In Delphi a message handler is created by including the message directive in a method declaration, followed by an integer constant between 1 and 49151 which specifies the message ID.

In CBuilder the routine for handling the message can be declared as by the VCL_MESSAGE_HANDLER macro.


For example the two message handlers:


  procedure WMVScroll(var Message: TWMVScroll); 
                      Message WM_VSCROLL;
  procedure WMHScroll(var Message: TWMHScroll); 
                      Message WM_HSCROLL;

are translated to CBuilder C++:


  MESSAGE void __fastcall WMVScroll( TWMVScroll& Message ) 
               /*# WM_VSCROLL */;
  MESSAGE void __fastcall WMHScroll( TWMHScroll& Message ) 
               /*# WM_HSCROLL */;


  BEGIN_MESSAGE_MAP
    VCL_MESSAGE_HANDLER(WM_VSCROLL, TWMVScroll, WMVScroll)
    VCL_MESSAGE_HANDLER(WM_HSCROLL, TWMHScroll, WMHScroll)
  END_MESSAGE_MAP( TPanel )



   deutsch Deutsch

 

 
Latest News
09/09/21
Delphi2CB: has been relased [more...]

08/06/21
Delphi2Cpp 2.0: DelphiXE2Cpp11 now is Delphi2Cpp 2.0 [more...]



"Thanks for your great work, really appreciate the work you have done on zlib and compiling ... test case."


Mattewada, Udayabhaskar
Nokia India 02/01/2021




[from case study...]

"A masterpiece -- Delphi2Cpp has exceeded all my expectations by far."


Tony Hürlimann
virtual-optima 08/20/2011



"First off, I have to say WOW! Delphi2Cpp is doing a *fantastic* job!"


Daniel Flower
linkrealms 01/15/2011


 
This website is generated from plain text with [Minimal Website ]

Minimal Website
Minimal Website is made with TextTransformer

TextTransformer
TextTransformer is made with Borland CBuilder

  borland