Scrollbar, hide main form, hide the titlebar, Combobox

[quote=mailto:info@delphitips.comGustav Evertsson]

How can I get a horizontal scrollbar on a list box?

Send a LB_SetHorizontalExtent message to the listbox's window handle.For example, the message could be sent in the form's OnCreate:

procedure TForm1.FormCreate(Sender: TObject);

begin

   SendMessage(Listbox1.Handle, LB_SetHorizontalExtent, 1000, Longint(0));

end;

---------------------------------------------End----------------------------------------------

How to hide the main form ?

If you do not want your program starting up showing your main form, then add this line in your project (DPR) file, just after the Application.Initialize line.

Application.ShowMainForm := False;

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How to hide the Titlebar ?

//Here is how to hide the titlebar:

Procedure TYourFormName.HideTitlebar;

Var

  Save : LongInt;

Begin

   If BorderStyle=bsNone then Exit;

   Save:=GetWindowLong(Handle,gwl_Style);

   If (Save and ws_Caption)=ws_Caption then

   Begin

      Case BorderStyle of bsSingle,

      bsSizeable : SetWindowLong(Handle,gwl_Style,Save and

                        (Not(ws_Caption)) or ws_border);

      bsDialog : SetWindowLong(Handle,gwl_Style,Save and

                     (Not(ws_Caption)) or ds_modalframe or ws_dlgframe);

      End;

      Height:=Height-getSystemMetrics(sm_cyCaption);

      Refresh;

   End;

end;

//And here is how we show it again:

Procedure TYourFormName.ShowTitlebar;

Var

  Save : LongInt;

begin

   If BorderStyle=bsNone then Exit;

   Save:=GetWindowLong(Handle,gwl_Style);

   If (Save and ws_Caption)<>ws_Caption then

   Begin

      Case BorderStyle of bsSingle,

      bsSizeable : SetWindowLong(Handle,gwl_Style,Save or

                        ws_Caption or ws_border);

      bsDialog : SetWindowLong(Handle,gwl_Style,Save or

                     ws_Caption or ds_modalframe or ws_dlgframe);

      End;

      Height:=Height+getSystemMetrics(sm_cyCaption);

      Refresh;

   End;

end;

---------------------------------------------End----------------------------------------------

How to make a TComboBox drop?

There is a windows API call to do it.

function SendMessage(Handle of the ComboBox, 1039, 1, 0);

So, if I had a TComboBox that was named LouieCombo, I would use the following code:

Procedure DropCombo(LouieCombo : TComboBox);

var

  ReturnValue : Longint;

begin

   ReturnValue := SendMessage(LouieCombo.Handle, 1039, 1, 0);

end;

---------------------------------------------End----------------------------------------------

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