Raising an event from a user control

  • Thread starter Thread starter RSH
  • Start date Start date
R

RSH

Hi,

I have been trying to follow a tutorial on raising an event from a user
control and then handling it in the parent page.

The article is a little vague so I believe I have the code in place, but I
cant seem to get it to work.

Here is what I have:

' This is in the ascx control:
' GeneralInfo is an ImageButton in the ascx file
Public MustInherit Class EmployeeNavigation

Inherits System.Web.UI.UserControl

Public Event GeneralInfoClicked(ByVal sender As System.Object, ByVal e
As System.Web.UI.ImageClickEventArgs)



' This fires when the imagebutton is clickedPrivate Sub
GeneralInfo_Clicked(ByVal sender As System.Object, ByVal e As
System.Web.UI.ImageClickEventArgs) Handles GeneralInfo.Click

RaiseEvent GeneralInfoClicked(sender, e)

End Sub

End Class





This is excerpts of the code I have in the aspx page which inherits the ascx
page above.

Protected WithEvents EmployeeNavigation As EmployeeNavigation

Private Sub GeneralInfo_Clicked(ByVal sender As Object, ByVal e As
System.Web.UI.ImageClickEventArgs) Handles
EmployeeNavigation.GeneralInfoClicked

Response.Write("<B> EVENT FIRED!</b>")



End Sub
 
RSH said:
I have been trying to follow a tutorial on raising an event from a user
control and then handling it in the parent page.

The article is a little vague so I believe I have the code in place, but I
cant seem to get it to work.

Here is what I have:

Public MustInherit Class EmployeeNavigation
Inherits System.Web.UI.UserControl

Public Event GeneralInfoClicked( _
ByVal sender As System.Object _
, ByVal e As System.Web.UI.ImageClickEventArgs _
)

' This fires when the imagebutton is clicked
Private Sub GeneralInfo_Clicked( _
ByVal sender As System.Object _
, ByVal e As System.Web.UI.ImageClickEventArgs _
) Handles GeneralInfo.Click
RaiseEvent GeneralInfoClicked(sender, e)
End Sub

End Class


This is excerpts of the code I have in the aspx page which inherits the ascx
page above.

Protected WithEvents EmployeeNavigation As EmployeeNavigation
Click to expand...

EmployeeNavigation is defined as MustInherit, so you cannot create
intances of it. I assume that you have a subclass somewhere that you
haven't shown us.

Since you're using inheritance, I would suggest handling the event this
way:

Public MustInherit Class EmployeeNavigation
Inherits System.Web.UI.UserControl

' This is the event exposed by this class (and its subclasses)
Public Event GeneralInfoClicked( _
ByVal sender As System.Object _
, ByVal e As System.Web.UI.ImageClickEventArgs _
)

' This fires when the imagebutton is clicked
' It uses the Protected method to raise the event.
Private Sub GeneralInfo_Clicked( _
ByVal sender As System.Object _
, ByVal e As System.Web.UI.ImageClickEventArgs _
) Handles GeneralInfo.Click

Me.OnGeneralInfoClicked(e)

End Sub

' This routine actually raises the event
' Subclasses can call this directly to get the event raised
Protected Sub OnGeneralInfoClicked( _
e As System.Web.UI.ImageClickEventArgs _
)

RaiseEvent GeneralInfoClicked(Me, e)

End Sub

End Class

Public Class SomeOtherEmployeeNavigation
Inherits EmployeeNavigation

' Note: NO click code in here;
' that's encapsulated in the base class

End Class

Then, in your aspx code:

Protected WithEvents navigator As SomeOtherEmployeeNavigation


HTH,
Phill W.
 
Phil,

Thanks a ton! That is good stuff!

Actually the MustInherit was a mistake, I didn't need that and as it turned
out naming the instance the same name as the class is what seemed to be
flaking eveything out.

But I learned a ton by your example and I appreciate your time!

Ron
 
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