Delphi : Prevent TPageControl Hint from showing on contained items.

Question

I have a form with the following components: A TPageControl containing a single TTabSheet, containing a TEdit.

I want a hint "Hello" displayed when I mouse over the pagecontrol tab, and no hint displayed when I mouse over the TEdit.

The PageControl has a hint= "Hello", and showhint = true. This works as expected.

The TEdit has showhint = false, parentshowhint = false, and hint is empty.

But, I still get a "Hello" hint whn I mouseover the TEdit. How can I stop this?

Here's the .dfm, if you're interested.

object Form65: TForm65
  Left = 0
  Top = 0
  Caption = 'Form65'
  ClientHeight = 258
  ClientWidth = 290
  OldCreateOrder = False
  ShowHint = True
  TextHeight = 13
  object PageControl1: TPageControl
    Left = 0
    Top = 0
    Width = 290
    Height = 258
    Hint = 'Bar'
    ActivePage = TabSheet1
    Align = alClient
    TabOrder = 0
    object TabSheet1: TTabSheet
      Caption = 'TabSheet1'
      object Edit3: TEdit
        Left = 72
        Top = 67
        Width = 121
        Height = 21
        ParentShowHint = False
        ShowHint = False
        TabOrder = 0
        Text = 'tab1'
      end
    end
  end
end

Answer 1

Add a TApplicationEvents control to your form, and use the OnShowHint event:

procedure TForm1.ApplicationEvents1ShowHint(var HintStr: string;
  var CanShow: Boolean; var HintInfo: THintInfo);
begin
  CanShow := HintInfo.HintControl <> Edit1;
end;

If you do not have the TApplicationEvents object in (e.g. if you are using a very old version of Delphi), then you can use (in FormCreate, for instance)

Application.OnShowHint := ApplicationEvents1ShowHint

to set the event handler manually.

Update

If you have more than one control in the TTabSheet, then you might have the same problem with them all. Then you might be interested in

procedure TForm1.ApplicationEvents1ShowHint(var HintStr: string;
  var CanShow: Boolean; var HintInfo: THintInfo);
begin
  CanShow := not SameStr(HintStr, PageControl1.Hint) or (HintInfo.HintControl = TabSheet1);
end;

Update 2

If you have several TTabSheets in the TPageControl, and want all sheets to display the hint, but non of the child controls, then you can do

  CanShow := not SameStr(HintStr, PageControl1.Hint) or
    ((HintInfo.HintControl is TTabSheet) and
      (TTabSheet(HintInfo.HintControl).PageControl = PageControl1));

instead.