This event appears to be invoked twice for absolutely no reason on only one
of my ASP.Net web user controls. Although I've now overcome the problem by
overriding the base classes OnLoad routine, I could never figure out why
this event was being invoked twice.
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
'Put user code to initialize the page here
End Sub
It inherits from the following superclass:
System.Web.UI.UserControl
This is the scenario:
When this 'Page_Load' routine was invoked; the call stack as soon as the
procedure begins shows (when non-user code was viewed) that the base classes
OnLoad routine invoked (by doing what ever it does) it.
The strange thing happened when the routine was exiting; I even removed ALL
of the code from the routine and debugged it whilst dissassembly was shown,
and as soon as the routine exited (via the assembler instruction RET 4) the
routine would IMMEDIATELY invoke again!!!
INFACT, the routine didn't even exit! it immediately went back to the top of
the routine and ran again.
The second time it would reach the end of the procedure (instruction RET 4
again) and would correctly return back to the calling method (OnLoad).
This appeared to be completely unpredictable behaviour; as the containing
code was getting executed twice (since i am expecting only 1 page_load per
build/teardown per object).
I can only theorise that somewhere, unless its a logic error of my own (but
I tested it in a seperate ASP Page, with just the user control removing
LOADS of code to test it; still did it) that its unpredictable behaviour
caused by event handling references.
What I would like to know is this:
Is there any advantages/disadvantages to just overiding the base classes
OnLoad routine?
One obvious advantage is you can chose when to invoke the base classes
OnLoad routine to continue normal processing. But I can't find any
disadvantages!
Secondly, has anyone else experienced such behaviour?
