Taskbar width, height and position

I need to get the width and height of the taskbar. Also I need the position 开发者_开发问答of the taskbar. How can I get this?

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Depending on what you need that information for, you might want to look into Forms.TScreen.WorkAreaRect, because the work-area identified that way subtracts not only the TaskBar, but also any other "bar" that might limit available Desktop space.

You can simply use Screen.WorkAreaRect from your code, because a Screen: TScreen variable is declared in the Forms unit and initialized by the VCL.

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Well, since this question is composed on how to get the task bar coordinates I've decided to post another version of how to achieve this by using SHAppBarMessage function with ABM_GETTASKBARPOS message parameter.

I've posted two versions; one with and one without given task bar handle. Note that if you are sending ABM_GETTASKBARPOS message you should specify the hWnd member in the APPBARDATA structure as it's mentioned in the ABM_GETTASKBARPOS description. So the first version is safe for this case. The second one works though but it's formally wrong.

uses ShellAPI;

procedure TForm1.Button1Click(Sender: TObject);
var
  Data: TAppBarData;
begin
  Data.hWnd := FindWindow('Shell_TrayWnd', nil);
  Data.cbSize := SizeOf(TAppBarData);

  if Data.hWnd <> 0 then
    if SHAppBarMessage(ABM_GETTASKBARPOS, Data) = 1 then
      ShowMessage(
                      'Left: ' + IntToStr(Data.rc.Left) + 'px ; ' +
                      'Top: ' + IntToStr(Data.rc.Top) + 'px ; ' +
                      'Width: ' + IntToStr(Data.rc.Right - Data.rc.Left) + 'px ; ' +
                      'Height: ' + IntToStr(Data.rc.Bottom - Data.rc.Top) + 'px'
                  );
end;

Note that this version (where the TAppBarData.hWnd member is not specified) works though but it's wrong according to the MSDN.

procedure TForm1.Button2Click(Sender: TObject);
var
  Data: TAppBarData;
begin
  Data.cbSize := SizeOf(TAppBarData);

  if SHAppBarMessage(ABM_GETTASKBARPOS, Data) = 1 then
    ShowMessage(
                    'Left: ' + IntToStr(Data.rc.Left) + 'px ; ' +
                    'Top: ' + IntToStr(Data.rc.Top) + 'px ; ' +
                    'Width: ' + IntToStr(Data.rc.Right - Data.rc.Left) + 'px ; ' +
                    'Height: ' + IntToStr(Data.rc.Bottom - Data.rc.Top) + 'px'
                );
end;

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This is what I've got (made in the Win95 decade ;-) and still working):

• GetTaskBarBounds
• GetTaskBarSize
• GetTaskBarAlignment

Here is the code:

const
 W95_EXPLORERCLASSNAME = 'Shell_TrayWnd';

function GetTaskBarBounds : TRect;
begin
 GetWindowRect( FindWindow( W95_EXPLORERCLASSNAME, '' ), Result );
end;

function GetTaskBarSize : TPoint;
var
 TaskBarBounds : TRect;

begin
 TaskBarBounds:=GetTaskBarBounds;
 with( TaskBarBounds ) do
  Result:=Point( Right - abs( Left ), Bottom - abs( Top ) );
end;

function GetTaskBarAlignment : TAlign;
var
 TaskBarBounds : TRect;

begin
 Result:=alNone;

 if( FindWindow( W95_EXPLORERCLASSNAME, '' ) > 0 ) then
  begin
   TaskBarBounds:=GetTaskBarBounds;

   with( TaskBarBounds ) do
    // At Left or at top of screen ?
    if( Left <= 0 ) and ( Top <= 0 ) then
     begin
      if( Bottom >= 480 ) then
       Result:=alLeft
      else Result:=alTop;
     end
    else begin
          if( Left <= 0 ) then
           Result:=alBottom
          else Result:=alRight;
         end;
  end;
end;

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Here is how you get the orientation

type
   TTaskBarPos = (_TOP, _BOTTOM, _LEFT, _RIGHT, _NONE);

function GetTaskBarPos: TTaskBarPos;
var
   hTaskbar: HWND;
   T: TRect;
   scrW, scrH: integer;
begin
   hTaskBar := FindWindow('Shell_TrayWnd', nil);
   if hTaskbar <> 0 then
   begin
     GetWindowRect(hTaskBar, T);
     ScrW := Screen.Width;
     ScrH := Screen.Height;
     if (T.Top > scrH div 2) and (T.Right >= scrW) then
       Result := _BOTTOM
     else if (T.Top < scrH div 2) and (T.Bottom <= scrW div 2) then
       Result := _TOP
     else if (T.Left < scrW div 2) and (T.Top <= 0) then
       Result := _LEFT
     else 
     if T.Left >= ScrW div 2 then
       Result := _RIGHT;
   end;
end;

procedure TForm1.Button5Click(Sender: TObject);
var
   TaskBarPos: TTaskBarPos;
begin
   TaskBarPos := GetTaskBarPos;
   case TaskBarPos of
     _LEFT: ShowMessage('Left Position');
     _TOP: ShowMessage('Top Position');
     _RIGHT: ShowMessage('Right Position');
     _BOTTOM: ShowMessage('Bottom Position');
   end;
end;

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I got this code from http://www.delphitips.net/2007/08/26/taskbar-position I tried this and works fine. It works even the size of the taskbar changes.

The code is put below.

procedure TForm1.Button1Click(Sender: TObject);
var
  hTaskbar: HWND;
  T: TRect;
  ScrW, ScrH: Integer;
begin
  ScrW := Screen.Width;
  ScrH := Screen.Height;
  hTaskBar := FindWindow('Shell_TrayWnd', nil);
  GetWindowRect(hTaskBar, T);
  if (T.Top > ScrH div 2) and (T.Right >= ScrW) then
    ShowMessage('Bottom of the screen')
  else if (T.Top < ScrH div 2) and (T.Bottom <= ScrW div 2) then
    ShowMessage('Top of the screen')
  else if (T.left < ScrW div 2) and (T.Top <= 0) then
    ShowMessage('Left side of the screen')
  else
    ShowMessage('Right side of the screen');
end;