Author: Tomas Rutkauskas

I have THeaderControl with 4 sections. When I resize the first section, I need the 
remaining 3 sections to resize proportionally to their size to ensure that they 
don't go out of visibility (I mean that the last section end position always 
remains the same). I tried to use OnSectionResize or OnSectionTrack events, but 
without success. Can anyone help?

Answer:
1   
2   procedure TForm1.ResizeMyHeader();
3   const
4     MIN_COL_WIDTH = 10;
5   var
6     iColWidth: Integer;
7     iColExtra: Integer;
8     iSection: Integer;
9   begin
10    if HeaderControl1.Sections.Count > 1 then
11    begin
12      iColWidth := HeaderControl1.Width;
13      Dec(iColWidth, HeaderControl1.Sections[0].Width);
14      iColWidth := (iColWidth div (HeaderControl1.Sections.Count - 1));
15      iColExtra := HeaderControl1.Width - (HeaderControl1.Sections[0].Width +
16        (HeaderControl1.Sections.Count - 1) * iColWidth);
17      {resize the 2nd to the last columns}
18      if iColWidth >= MIN_COL_WIDTH then
19      begin
20        for iSection := 1 to HeaderControl1.Sections.Count - 2 do
21        begin
22          HeaderControl1.Sections[iSection].Width := iColWidth;
23        end;
24        HeaderControl1.Sections[HeaderControl1.Sections.Count - 1].Width := iColWidth 
25  + iColExtra;
26      end;
27    end;
28  end;
29  
30  procedure TForm1.HeaderControl1_OnSectionResize(HeaderControl: THeaderControl;
31    Section: THeaderSection);
32  begin
33    Self.ResizeMyHeader;
34  end;
35  
36  procedure TForm1.Form_OnResize(Sender: TObject);
37  begin
38    Self.ResizeMyHeader;
39  end;