delphi 设置默认控件得到焦点

如果同一窗体有多个按钮的话，追踪源码发现最后是taborder来的

如： 在空白窗体上拖入两个button (btn1,btn2) 

如果在btn2设置default = True 运行后，默认焦点还是在btn1上。需要把btn2的taborder设置为0才可以。

如此看来还是以taborder 来认的。

procedure TCustomForm.SetActive(Value: Boolean);
begin
  FActive := Value;
  if FActiveOleControl <> nil then
    FActiveOleControl.Perform(CM_DOCWINDOWACTIVATE, Ord(Value), 0);
  if Value then
  begin
    if (ActiveControl = nil) and not (csDesigning in ComponentState) then
      ActiveControl := FindNextControl(nil, True, True, False);
    MergeMenu(True);
    SetWindowFocus;
  end;
end;

其中的 FindNextControl 可以看出是gettaborderlist来认的

function TWinControl.FindNextControl(CurControl: TWinControl;
  GoForward, CheckTabStop, CheckParent: Boolean): TWinControl;
var
  I, StartIndex: Integer;
  List: TList;
begin
  Result := nil;
  List := TList.Create;
  try
    GetTabOrderList(List);
    if List.Count > 0 then
    begin
      StartIndex := List.IndexOf(CurControl);
      if StartIndex = -1 then
        if GoForward then StartIndex := List.Count - 1 else StartIndex := 0;
      I := StartIndex;
      repeat
        if GoForward then
        begin
          Inc(I);
          if I = List.Count then I := 0;
        end else
        begin
          if I = 0 then I := List.Count;
          Dec(I);
        end;
        CurControl := List[I];
        if CurControl.CanFocus and
          (not CheckTabStop or CurControl.TabStop) and
          (not CheckParent or (CurControl.Parent = Self)) then
          Result := CurControl;
      until (Result <> nil) or (I = StartIndex);
    end;
  finally
    List.Free;
  end;
end;