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Delphi TListview OwnerDraw SubItems - change default font (it's bold somehow after you Draw on the canvas)

If you use ownerdraw with a TListView, the subitems are all BOLD font style by default somehow, even if the listview font.style is set to [], for all the SubItems following a custom drawn one.

A workaround I found is forcing the Style set in the CustomDrawSubItem event:

ListView2.Canvas.Font.Style := [fsItalic];
ListView2.Canvas.Font.Style := [];

(a simple call with [] won't work unless the default style is set to something other than [], because the SetStyle call doesn't think the style has changed)

This is however an ugly fix which involves extra processing time. Is there a better solution?

Demo project: http://www.mediafire.com/?v8bsdpvpfqy47vn

like image 265
hikari Avatar asked Feb 18 '23 10:02

hikari


1 Answers

I haven't encountered the exact situation you describe, but I have encountered a similar issue. When I use an owner-drawn TListView with an OnAdvancedCustomDrawSubItem event assigned to change the Canvas.Font on a per-subitem basis, I find that after I have changed the Sender.Canvas.Font for one subitem, subsequent subitems get drawn with the wrong settings even if I change the Sender.Canvas.Font for them. My workaround is to manually call the Sender.Canvas.Font.OnChange event handler at the end of my OnAdvancedCustomDrawSubItem event handler. That signals TListView to report back CDRF_NEWFONT to Windows, then everything gets drawn correctly. It is as if the Sender.Canvas.Font.OnChange event is not hooked up correctly while TListView is being owner-drawn, so it does not detect font changes and thus does not report back to Windows correctly.

like image 64
Remy Lebeau Avatar answered May 16 '23 06:05

Remy Lebeau