Why can't I access the width of a THeaderSection - c++builder

Question

I'm trying to use the width of a headersection in a THeaderControl in C++ Builder XE.
The THeaderControl is called "Header"
The TStringGrid I'm trying to align the widths with is called "Grid".
In the OnResize event handler for the Header, I've got the following code :
void __fastcall TMainForm::HeaderResize(TObject *Sender)
{
for (int col=0; col<Header->Sections->Count; col++)
{
Grid->ColWidths[col]=Header->Sections[0].Width;
}
}
which I thought would be OK, but it won't compile.
Can't seem to find out how to access the widths of the header.
Also, when i stuff something in here just to get it to compile (e.g. Grid->ColWidths[col]=100), the HeaderResize event handler doesn't get called (i.e. if I put a breakpoint in this loop, run the program and resize the header, it doesn't get to the breakpoint).

Answer 1

You are not accessing the individual headers sections correctly. You need to do it like this instead:
void __fastcall TMainForm::HeaderResize(TObject *Sender)
{
for (int col=0; col<Header->Sections->Count; col++)
{
Grid->ColWidths[col] = Header->Sections->Items[col]->Width;
}
}
Notice that Sections[col] is replaced with Sections->Items[col], and that .Width is replaced with ->Width.
As for the OnResize event not being triggered, OnResize is only triggered when the entire THeaderControl is resized. When resizing individual sections, the OnSectionResize event is triggered instead. That event tells you which section was resized, eg:
void __fastcall TMainForm::HeaderSectionResize(TCustomHeaderControl *HeaderControl, THeaderSection *Section)
{
Grid->ColWidths[Section->Index] = Section->Width;
}