调用RoutedEvent时的ArgumentNullException

Question

下面的代码生成一个ArgumentNullException：

Public Custom Event PlayerDetailRequested As RoutedPropertyChangedEventHandler(Of Player)

    AddHandler(ByVal value As RoutedPropertyChangedEventHandler(Of Player))
        Me.AddHandler(PlayerDetailRequestedEvent, value)
    End AddHandler

    RemoveHandler(ByVal value As RoutedPropertyChangedEventHandler(Of Player))
        Me.RemoveHandler(PlayerDetailRequestedEvent, value)
    End RemoveHandler

    RaiseEvent(ByVal sender As Object, ByVal e As RoutedPropertyChangedEventArgs(Of Player))
        Me.RaiseEvent(e)
    End RaiseEvent
End Event

Public Shared ReadOnly PlayerDetailRequestedEvent As RoutedEvent = _
                  EventManager.RegisterRoutedEvent("PlayerDetailRequested", _
                  RoutingStrategy.Bubble, _
                  GetType(RoutedPropertyChangedEventHandler(Of Player)), GetType(PlayersManagementControl))



  Private Sub Hyperlink_Click(sender As Object, e As RoutedEventArgs)
        RaiseEvent PlayerDetailRequested(Me, New RoutedPropertyChangedEventArgs(Of Player)(SelectedPlayer, SelectedPlayer))
    End Sub

在调用Me.RaiseEvent(e)时引发异常

在VB和C中很难找到工作的例子，因为它们的事件处理是不同的。请帮我保持理智！

Answer 1

这个问题在Exception：Value cannot be null. Parameter name: routedEvent中有解释。RoutedEvent是RoutedEventArgs的属性。您必须提供您正在提升的RoutedEvent实例，在本例中它是PlayerDetailRequestedEvent。试试这段代码：

    Private Sub Button_Click_1(sender As Object, e As RoutedEventArgs)
            Me.RaiseEvent(New RoutedPropertyChangedEventArgs(Of Player)(SelectedPlayer, SelectedPlayer, PlayerDetailRequestedEvent))
    End Sub