FireMonkey FlowLayout 不刷新基于可见属性的项目

Question

How are you? Hope you doing fine. My question: I have a FlowLayout with a lot of layouts inside it, and I need to hide a few based on a radio button selection, in design time it works fine I set the visible property to false and all the other layouts realign the right way, but when I do this at runtime it doesn't work, it keeps a white gap between the layout that has been hidden and the next one. When I do a resize manually (go to the form border and drag a little) it realigns and gets right, but if I select another radio the layout gets back and it override another layout so I need to resize manually again to realign. I tried to look at the source code of Resize but I got nothing relevant. What I tried: Repaint, Realign, InvalidateRect, RecalcAbsolute. Is there any way that I have to force the refresh of components?

procedure
    TFrmApontamentoProducaoOrdemProducao.rbOrdensProducaoQuantidadeParcialClick(
    Sender: TObject);
begin
  if not lytQuantidadeParcial.Visible then
    lytQuantidadeParcial.Visible := True;
  // Tried to realign here
end;

procedure
    TFrmApontamentoProducaoOrdemProducao.rbOrdensProducaoQuantidadeTotalClick(
    Sender: TObject);
begin
  if lytQuantidadeParcial.Visible then
    lytQuantidadeParcial.Visible := False;
  // Tried to realign here
end;

It's a simple code, but it's giving me a little problem. Thanks for the help, if you need more code or more details just let me know.

Answer 1

You must surround your code that makes changes to the layout of the TFlowLayout with a pair of FlowLayout1.BeginUpdate; and FlowLayout1.EndUpdate; To assure that the update counter stays in sync, you should also use a try..finally..end block.

For example

procedure TForm21.Button6Click(Sender: TObject);
begin
  FlowLayout1.BeginUpdate;
  try
    Layout3.Visible := not Layout3.Visible;
  finally
    FlowLayout1.EndUpdate;
  end;
end;

Answer 2

Using BeginUpdate cause access violation on a project when insert chars from tcp-ip comunication in real time on FlowLayout, the solution:

var PodeAtualizarGrade:TCriticalSection; ...

FormCreate PodeAtualizarGrade:=TCriticalSection.Create; ...

PodeAtualizarGrade.Enter;

(FlowLayout.AddObjects )

PodeAtualizarGrade.Leave;

Works fine on my project.