Forcing focus

**aidave** · 20-03-2006, 04:48 PM

Is there any way to force the focus of a form?

When my game starts up,
and you click on another window while its loading,
I try "SetFocus"
but the focus still stays on the other window.

**jdarling** · 20-03-2006, 06:11 PM

This is actually quite a bit of a tricky task to pull off. In most cases you can get away with the following (but not all):

[pascal]procedure ForceFocus(AForm:TForm);
begin
Application.SetFocus;
Application.Focus(AForm);
Application.BringToFront;
AForm.BringToFront;
end;[/pascal]

I may have a mis-type in there, as normal I'm working w/o a net (IDE). The idea is there. Note that this will not fix the modal issues in Windows XP, that requires another hack all together.

**aidave** · 20-03-2006, 07:06 PM

Interesting, i just tried it, but didnt work.
I am using XP, I'm guessing XP tries to stop this activity.

Its really just an issue when developing,
having the IDE on my second monitor and switching.
But then my app strangles the mouse away..
yet the app stays unfocused!

these:
Application.SetFocus;
Application.Focus(AForm);
dont work in d7

these:
Application.BringToFront;
AForm.BringToFront;
make it glow orange in XP :lol:

thanx
dave

LP · 21-03-2006, 05:57 PM

Few years ago I've used the following function (found somewhere on Internet). Let me know if it works:

Code:

function ForceForegroundWindow&#40;hwnd&#58; THandle&#41;&#58; Boolean;
const
 SPI_GETFOREGROUNDLOCKTIMEOUT = $2000;
 SPI_SETFOREGROUNDLOCKTIMEOUT = $2001;

var
 ForegroundThreadID&#58; LongWord;
 ThisThreadID&#58; LongWord;
 timeout&#58; LongWord;
begin
 if &#40;IsIconic&#40;hwnd&#41;&#41; then
  ShowWindow&#40;hwnd, SW_RESTORE&#41;;

 if &#40;GetForegroundWindow = hwnd&#41; then
  begin
   Result&#58;= True;
   Exit;
  end;

 // Windows 98/2000 doesn't want to foreground a window when some other
 // window has keyboard focus
 if &#40;&#40;Win32Platform = VER_PLATFORM_WIN32_NT&#41;and&#40;Win32MajorVersion > 4&#41;&#41;or
  &#40;&#40;Win32Platform = VER_PLATFORM_WIN32_WINDOWS&#41; and
  &#40;&#40;Win32MajorVersion > 4&#41; or &#40;&#40;Win32MajorVersion = 4&#41; and
  &#40;Win32MinorVersion > 0&#41;&#41;&#41;&#41; then
  begin
   // Code from Karl E. Peterson, www.mvps.org/vb/sample.htm
   // Converted to Delphi by Ray Lischner
   // Published in The Delphi Magazine 55, page 16
   Result&#58;= False;
   ForegroundThreadID&#58;= GetWindowThreadProcessID&#40;GetForegroundWindow, nil&#41;;
   ThisThreadID&#58;= GetWindowThreadPRocessId&#40;hwnd, nil&#41;;
   if &#40;AttachThreadInput&#40;ThisThreadID, ForegroundThreadID, True&#41;&#41; then
    begin
     BringWindowToTop&#40;hwnd&#41;; // IE 5.5 related hack
     SetForegroundWindow&#40;hwnd&#41;;
     AttachThreadInput&#40;ThisThreadID, ForegroundThreadID, False&#41;;
     Result&#58;= &#40;GetForegroundWindow = hwnd&#41;;
    end;

   if &#40;not Result&#41; then
    begin
     // Code by Daniel P. Stasinski
     SystemParametersInfo&#40;SPI_GETFOREGROUNDLOCKTIMEOUT, 0, @timeout, 0&#41;;
     SystemParametersInfo&#40;SPI_SETFOREGROUNDLOCKTIMEOUT, 0, TObject&#40;0&#41;, SPIF_SENDCHANGE&#41;;
     BringWindowToTop&#40;hwnd&#41;; // IE 5.5 related hack
     SetForegroundWindow&#40;hWnd&#41;;
     SystemParametersInfo&#40;SPI_SETFOREGROUNDLOCKTIMEOUT, 0, TObject&#40;timeout&#41;, SPIF_SENDCHANGE&#41;;
    end;
  end else
   begin
    BringWindowToTop&#40;hwnd&#41;; // IE 5.5 related hack
    SetForegroundWindow&#40;hwnd&#41;;
   end;

 Result&#58;= &#40;GetForegroundWindow = hwnd&#41;;
end;

Just use it like: ForceForegroundWindow(Form1.Handle);