Source object does not expose IConnectionPointContainer problem

  • Thread starter Thread starter GS
  • Start date Start date
G

GS

in a class WebCtlExt inherited from system.windows.form.webbrowser, I have

Private cookie As AxHost.ConnectionPointCookie
Private wevents As WebBrowserExtendedEvents
.......

Protected Overrides Sub CreateSink()
'MAKE SURE TO CALL THE BASE or the normal events won't fire
MyBase.CreateSink()
wevents = New WebBrowserExtendedEvents(Me)
cookie = New AxHost.ConnectionPointCookie(Me.ActiveXInstance,
wevents, GetType(DWebBrowserEvents2)) ' <<< oops error
End Sub


....
end class
<ComImport(), _
Guid("34A715A0-6587-11D0-924A-0020AFC7AC4D"), _
InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIDispatch), _
TypeLibType(TypeLibTypeFlags.FHidden)> _
Public Interface DWebBrowserEvents2

<DispId(250)> _
Sub BeforeNavigate2(<[In](), MarshalAs(UnmanagedType.IDispatch)> ByVal
pDisp As Object, _
<InAttribute(), MarshalAs(UnmanagedType.BStr)> ByRef URL As String, _
<InAttribute()> ByRef flags As Object, _
<InAttribute(), MarshalAs(UnmanagedType.BStr)> ByRef targetFrameName As
String, _
<InAttribute()> ByRef postdata As Object, _
<InAttribute(), MarshalAs(UnmanagedType.BStr)> ByRef headers As String,
_
<InAttribute(), OutAttribute()> ByRef cancel As Boolean)

'Note: Postdata is a SafeArray but for some reason, if I do a proper
declaration, the event will not be raised:
'<[In](), MarshalAs(UnmanagedType.SafeArray,
safearraysubtype:=VarEnum.VT_UI1)> ByRef postdata() As Byte, _

<DispId(273)> _
Sub NewWindow3(<InAttribute(), MarshalAs(UnmanagedType.IDispatch)> ByVal
pDisp As Object, _
<InAttribute(), OutAttribute()> ByRef cancel As Boolean, _
<InAttribute()> ByRef Flags As Object, _
<InAttribute(), MarshalAs(UnmanagedType.BStr)> ByRef UrlContext As
String, _
<InAttribute(), MarshalAs(UnmanagedType.BStr)> ByRef Url As String)

End Interface 'DWebBrowserEvents2

' ---------ERROR msg ::::::::::::::
System.InvalidCastException was unhandled by user code
Message="Source object does not expose IConnectionPointContainer."
Source="System.Windows.Forms"
StackTrace:
at System.Windows.Forms.AxHost.ConnectionPointCookie..ctor(Object
source, Object sink, Type eventInterface, Boolean throwException)
at System.Windows.Forms.AxHost.ConnectionPointCookie..ctor(Object
source, Object sink, Type eventInterface)
at myapp.WebCtlExt.CreateSink() in c:\myApp\webCtlExt.vb:line 104
at myapp.WebCtlExt.CreateSink_() in c:\myApp\webCtlExt.vb:line 96
at myapp.webCtl.webCtl_Load(Object sender, EventArgs e) in
c:\myApp\webCtl.vb:line 13
at System.EventHandler.Invoke(Object sender, EventArgs e)
at System.Windows.Forms.UserControl.OnLoad(EventArgs e)
at System.Windows.Forms.UserControl.OnCreateControl()
at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
at System.Windows.Forms.Control.CreateControl()
at System.Windows.Forms.Control.SetVisibleCore(Boolean value)


what should my code be?

I am using vistual studio 2005 vb express dotnet2.

thank you
 
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