delphi – ManualFloat没有使用指定的Rect

ManualFloat创建一个浮动窗口并在TControl.CreateFloatingDockSite(Bounds：TRect)中设置其Top,Left值,然后设置其ClientWidth.

这是一个错误,因为这样做会强制WindowHandle创建(它还没有Handle)

function TCustomForm.GetClientRect: TRect;
begin
  if IsIconic(Handle) then // <===

并调用Window的默认定位(级联yadda yadda …)重置Top和Left

修复方法是在TControl.CreateFloatingDockSite中设置Top和Left属性之前设置ClientWidth和ClientHeight(Bounds：TRect)

更新：Controls.pas中的固定代码

function TControl.CreateFloatingDockSite(Bounds: TRect): TWinControl;
begin
  Result := nil;
  if (FloatingDockSiteClass <> nil) and
    (FloatingDockSiteClass <> TWinControlClass(ClassType)) then
  begin
    Result := FloatingDockSiteClass.Create(Application);
    with Bounds do
    begin
      // Setting Client area can create the window handle and reset Top and Left
      Result.ClientWidth := Right - Left;
      Result.ClientHeight := Bottom - Top;
      // It is now safe to position the window where asked
      Result.Top := Top;
      Result.Left := Left;
    end;
  end;
end;