TControlList scrolls list when a record is changed when using LiveBindings

Question

To reproduce: Set up a TControlList with LiveBindings to a DataSet and assign an OnClick event that just does:

DataSet.Edit;
DataSet.Post;

Now when you click on a cell it will scroll that cell to be in the last row of the list (assuming you've already scrolled down far enough).

This is probably a bug, but is there a way I can prevent the repositioning of the visible items in the list?

Using Delphi 10.4.2

Answer 1

I couldn't find a "nice" solution to this, so I went down the RTTI route. We need to access the private FScrollPos field, remember what it is before we change a record in the dataset, then reset it back.

procedure TForm7.ControlList1Click(Sender: TObject);
var
  OldScrollPos : integer;
begin
  inherited;
  OldScrollPos := TRttiContext.Create.GetType(TControlList).GetField('FScrollPos').GetValue(Sender).AsInteger;
  DataSet.Edit;
  DataSet.Post;
  TRttiContext.Create.GetType(TControlList).GetField('FScrollPos').SetValue(Sender, OldScrollPos);
end;

This removes the "scroll item to the bottom row" behaviour when we alter a record. You will need to add System.RTTI to your uses.