How to ListView VCL collapse / expand by code?

Question

I'm using Delphi 10.1 and VCL. How to collapse or expand all or specific Groups by code?

Answer 1

The expansion state is in the group's State property. For instance, to collapse the first group:

ListView1.Groups[0].State := ListView1.Groups[0].State + [lgsCollapsed];

There is no shortcut for processing all groups at once. You have to loop through them one at a time:

for I := 0 to ListView1.Groups.Count-1 do
begin
  ListView1.Groups[I].State := ListView1.Groups[I].State + [lgsCollapsed];
end;