1 var
 2   I: Integer;
 3   S1 : TUniTreeNode;
 4 begin
 5   UniTreeView1.BeginUpdate;   // Needed when making large additions to tree nodes
 6   try
 7    for I := 0 to 250 do
 8   begin
 9     S1 := UniTreeView1.Items.AddChild(nil, ‘Sub Node ‘+IntToStr(I));
10   end;
11   finally
12     UniTreeView1.EndUpdate;   // Whole tree data will be sent in one Json array
13   end;
14 end;