Posting Messages

[Andrew Truckle]

I have a thread which sends user defined messages to another window.

How can I get it to send a text string?

For example, the window which receives a certain message has a static text control which I would like to update.

At the moment I have derived a series of CONSTANTS and sent those. Then the message handler sets the text according to which CONSTANT was received.

There must be a more flexible approach.

I hope someone can help.

In the thread you can send the message using something like:

CString sendstring = _T("Send this text");
char *lpszPostedBytes = (char *) LocalAlloc(LPTR,sendstring.Length() + 1);
if (lpszPostedBytes != NULL)
{
strcpy(lpszPostedBytes, (LPCTSTR) sendstring);
PostMessage(myWnd, YOUR_MESSAGE, (LPARAM) lpszPostedBytes, 0L);
}

Then release the memory when the message been processed using:
LocalFree();

[anuvk]

I HAVE done this before...
I did Send Message() ;
I didnt find the necessity for any user defined messages
U can instead adhere to WM_SETTEXT
It worked perfectly

SendMessage to main app from a thread is DANGEROUS. It can cuase dead locks. Don't do it!

[Andrew Truckle]

Hi, thanks for your sample code.

I've added it in, but have one problem. How to I do when the message has been processed so that I can call LocalFree()?

[sally]

LocalFree is called on the receiving side

Sally

[Sally]

LocalFree is called on the receiving side

Sally

[Andrew Truckle]

Hi Sally

I've tried putting LocalFree(var) into the message handler function, but it doesn't like the parameter being passed which is now a LPARAM.

Any ideas?

[MikeL]

LocalFree((char*) var)?

Sure, for some strange reason I couldn't log in today.....

you have to cast the LPARAM to the correct datatype to be freed

Sally