在vb.net中访问声明的事件时遇到问题

Question

Facing an issue while accessing declared event in vb.net.

Please go thorough below example. (I have modified below stuff to make understable as it is part of one of custom control development)

Public Class Main
    Inherits ComboBox

    'Event handler for when an item check state changes.
    Public Event ItemCheck As ItemCheckEventHandler
    Private parentMainClass As Main
    Private cclb As controlClass

    Public Sub New(parentclass As Main)
        Me.parentMainClass = parentclass
        'Add a handler to notify our parent of ItemCheck events.
        AddHandler Me.cclb.ItemCheck, New System.Windows.Forms.ItemCheckEventHandler(AddressOf Me.cclb_ItemCheck)
    End Sub

    Private Sub cclb_ItemCheck(sender As Object, e As ItemCheckEventArgs)
        'If ccbParent.ItemCheck IsNot Nothing Then
            RaiseEvent parentMainClass.ItemCheck(sender,e)
        'End If
    End Sub

    Public Class controlClass
        Inherits CheckedListBox
    End Class
End Class

Problem: RaiseEvent parentMainClass.ItemCheck(sender,e) this statement shows - ItemCheck event not exists even though it is existed.

Please guide.

Thank You

Answer 1

The event declaration;

Public Event ItemCheck As ItemCheckEventHandler

Should be;

Public Event ItemCheck(sender As Object, e As ItemCheckEventArgs)

What the error is telling you is that it cannot match up the event to the event handler signature.

Answer 2

From your original code, the line;

RaiseEvent parentMainClass.ItemCheck(sender, e)

should be changed to;

RaiseEvent ItemCheck(sender, e)

This raises the ItemCheck event from the current instance. What you seem to be wanting to do is to raise the event on the parent instance, which is a bit different.