• Mark Moorhen (25/25) Nov 04 2018 Another Windows challenge:
• John Chapman (10/35) Nov 04 2018 You need to allocate some memory to receive the string from
• Mark Moorhen (2/2) Nov 05 2018 Brilliant! Thanks John

Mark Moorhen <Mark Moorhen.com> writes:

Another Windows challenge:

I'm trying to get the title of the active window even if it is 
from an external application. This is what I've come up with so 
far:

<D>
import std.stdio;
import core.sys.windows.windows;

extern (Windows)

void main()
{
	HWND foreground = GetForegroundWindow();
	const(wchar) title;

	int length = SendMessage(foreground, WM_GETTEXTLENGTH, 0, 0);
	SendMessage(foreground, WM_GETTEXT, length, 
LPARAM(title));			//LPARAM is a Long Pointer

	writeln(length);
	writeln(title);

}
</D>

Outputs :

27                                                                
                                                       ´┐┐

So the lengt of the foreground windows title should be 27 chars 
long, but the title is only 3 chars (and kinda funny ones too:-(

Anyone ideas?

John Chapman <johnch_atms hotmail.com> writes:

On Sunday, 4 November 2018 at 19:06:22 UTC, Mark Moorhen wrote:
 Another Windows challenge:

 I'm trying to get the title of the active window even if it is 
 from an external application. This is what I've come up with so 
 far:

 <D>
 import std.stdio;
 import core.sys.windows.windows;

 extern (Windows)

 void main()
 {
 	HWND foreground = GetForegroundWindow();
 	const(wchar) title;

 	int length = SendMessage(foreground, WM_GETTEXTLENGTH, 0, 0);
 	SendMessage(foreground, WM_GETTEXT, length, 
 LPARAM(title));			//LPARAM is a Long Pointer

 	writeln(length);
 	writeln(title);

 }
 </D>

 Outputs :

 27
                                                       ´┐┐

 So the lengt of the foreground windows title should be 27 chars 
 long, but the title is only 3 chars (and kinda funny ones too:-(

 Anyone ideas?

You need to allocate some memory to receive the string from 
WM_GETTEXT.

   auto length = SendMessage(foreground, WM_GETTEXTLENGTH, 0, 0);
   auto buffer = new wchar[length + 1]; // +1 for the trailing 
null character
   SendMessage(foreground, WM_GETTEXT, buffer.length, 
cast(LPARAM)buffer.ptr);
   auto title = cast(wstring)buffer[0 .. length];
   writeln(title);

Mark Moorhen <Mark Moorhen.com> writes:

Brilliant! Thanks John
!