How to use SendMessage to another form in same app

Posted by Robert Frank on Stack Overflow See other posts from Stack Overflow or by Robert Frank
Published on 2010-05-23T00:04:54Z Indexed on 2010/05/23 0:10 UTC
Read the original article Hit count: 282

Filed under:

delphi

I've been trying to get this to work for some time now and can't figure it out. Probably obvious once you know it.

I simply want a non-modal form (or perhaps an instantiated non-TForm class) to send a message to the application's main form.

I can make the main form send a message to itself and receive (announcing with a beep)

But, I can't seem to have other objects send messages to the main form.

I'm using WM_MY_MESSAGE = WM_APP + 200;

What should the first argument of the SendMessage be to send a message to the main form? Even sending it to Application.MainForm.Handle doesn't seem to work.

The reason I need to do this is that the modal form has a slider that another form (#2) needs to know when it changes. Notifying the other form via a callback procedure was making it sluggish as form #2 did some work before returning from the call. Is having a modal form send a windows message to the main form a reasonable way to avoid this?

Related posts about delphi

TVirtualStringTree compatibility between Delphi 7 and Delphi 2010 - 'Parameter lists differ'

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I've made a form containing a TVirtualStringTree that works in Delphi 7 and Delphi 2010. I notice that as I move between the two platforms I get the message '...parameter list differ..' on the tree events and that the string type is changing bewteen TWideString (D7) and string (D2010). The only… >>> More
Convert Delphi 7 code to work with Delphi 2009

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a String that I needed access to the first character of, so I used stringname[1]. With the unicode support this no longer works. I get an error: [DCC Error] sndkey32.pas(420): E2010 Incompatible types: 'Char' and 'AnsiChar' Example code: //vkKeyScan from the windows unit var KeyString:… >>> More
Book recommendation for moving from Delphi 6 to Delphi 2010

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am a long time Delphi 6 developer. Looking for a book on Delphi 2010. Not only on the new features available in Delphi 2010, but more importantly, guideline on how different it is to develop applications in Delphi 2010, the architecture, standard and convention, etc. Thanks a lot. >>> More
Compile Delphi component package (bpl) for different Delphi versions

as seen on Stack Overflow - Search for 'Stack Overflow'
Hello. The situation is the following. Typically I use RAD Studio 2010 for Delphi development. I have some components I would like to redistribute in binary form (*.bpl without source). But I would like people to be able to use them despite of their Delphi version. But, for example, dcu files can… >>> More
Delphi Speech recognition delphi

as seen on Stack Overflow - Search for 'Stack Overflow'
I need create a programatic equivalent using delphi language... or could someone post a link on how to do grammars in peech recogniton using the delphi. sorry for my english... XML Grammar Sample(s): <GRAMMAR>  <RULE NAME="HelloWorld"… >>> More

Developer IT