Invalidates the column header panel.
The InvalidateColumnPanel method repaints the column headers and column button of the TreeList control. This can be used if you want the mentioned elements to change their appearance at times when not repainted automatically. For instance, expanding nodes or scrolling through rows doesn't invoke column panel repainting. Thus, you must force column header panel repainting manually if its appearance must be changed due to these actions.
Generally, the following must be done in order to use the InvalidateColumnPanel effectively.
- Write a TreeList.CustomDrawColumnHeader event handler. This enables you to paint column headers and the column button with respect to some custom conditions.
- Call the InvalidateColumnPanel method when the mentioned conditions have been changed (if these changes don't force repainting automatically).
Use the TreeList.InvalidateColumnHeader method to control repainting of individual column headers.