Mega Code Archive
Capture the tab key in a tedit
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Problem/Abstract: It's not possible to trap the tabulator-key in the
OnkeyPress/OnkekDown/OnkeyUp handler of a TEdit control.
Here are two ways to trap it!
Problem: Es ist nicht möglich, im OnkeyPress/OnkekDown/OnkeyUp eines
TEdits festzustellen, ob die Tabulatortaste gedrückt wurde.
Hier sind zwei Möglichkeiten, wie man sie trotzdem abfangen kann!}
private
Procedure CMDialogKey(Var Msg: TWMKey); message CM_DIALOGKEY;
{...}
Procedure TForm1.CMDialogKey(Var Msg: TWMKEY);
Begin
If (ActiveControl = Edit1) Then
If Msg.Charcode = VK_TAB Then
begin
ShowMessage('Tab');
{ Msg.Charcode := 0; } // to eat the tab key!
end;
inherited;
End;
{**** Or/ Oder: ****}
private
Procedure CMDialogKey(Var Msg: TWMKey); message CM_DIALOGKEY;
{...}
procedure TForm1.CMDialogKey(var Msg: TWMKey);
begin
if (Edit1.Focused) then
Msg.Result := 0
else
inherited;
end;
procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
if Ord(Key) = VK_TAB then
begin
ShowMessage('Tab');
Key := #0; // no beep!
end;
end;
{**** Or/ Oder: ****}
(by Peter Larson)
{By adding a message handler for WM_GETDLGCODE to a component,
it is possible for a component to capture the tab key.
The tab key will be passed to the OnKeyDown event handler like other keys.
The following D4 code shows what needs to be added to a component to allow
the capture of the tab key.}
Type
TExtEdit = Class(tEdit)
Private
procedure WMGetDlgCode(var Message: TWMGetDlgCode); message WM_GETDLGCODE;
End;
{...}
procedure TExtEdit.WMGetDlgCode(var Message: TWMGetDlgCode);
Begin
Inherited;
Message.Result := Message.Result or DLGC_WANTTAB;
End;
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