Imports System.Runtime.InteropServices

<ComImport(), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("00000016-0000-0000-C000-000000000046")> Public Interface IMessageFilter

    <PreserveSig()> _
    Function HandleInComingCall(ByVal dwCallType As Integer, ByVal hTaskCaller As IntPtr, ByVal dwTickCount As Integer, ByVal lpInterfaceInfo As IntPtr) As Integer

    <PreserveSig()> _
    Function RetryRejectedCall(ByVal hTaskCallee As IntPtr, ByVal dwTickCount As Integer, ByVal dwRejectType As Integer) As Integer

    <PreserveSig()> _
    Function MessagePending(ByVal hTaskCallee As IntPtr, ByVal dwTickCount As Integer, ByVal dwPendingType As Integer) As Integer
End Interface

Public Class frmMain 'rename this to match your form name
    Implements IMessageFilter
    Private Declare Function CoRegisterMessageFilter Lib "ole32.dll" (ByVal lpMessageFilter As IMessageFilter, ByRef lplpMessageFilter As IMessageFilter) As Integer
    Function IMessageFilter_HandleInComingCall(ByVal dwCallType As Integer, ByVal hTaskCaller As IntPtr, ByVal dwTickCount As Integer, ByVal lpInterfaceInfo As IntPtr) As Integer Implements IMessageFilter.HandleInComingCall
        Return 0
        ' SERVERCALL_ISHANDLED
    End Function

    Function IMessageFilter_RetryRejectedCall(ByVal hTaskCallee As IntPtr, ByVal dwTickCount As Integer, ByVal dwRejectType As Integer) As Integer Implements IMessageFilter.RetryRejectedCall
        Return 1000
        ' Retry in a second
    End Function

    Function IMessageFilter_MessagePending(ByVal hTaskCallee As IntPtr, ByVal dwTickCount As Integer, ByVal dwPendingType As Integer) As Integer Implements IMessageFilter.MessagePending
        Return 1
        ' PENDINGMSG_WAITNOPROCESS
    End Function

    Public Sub New()
        ' This call is required by the Windows Form Designer.
        InitializeComponent()

        ' Add any initialization after the InitializeComponent() call.
        Dim oldFilter As IMessageFilter
        CoRegisterMessageFilter(Me, oldFilter)
    End Sub
'put your form code here, and if you have a Sub New, make sure to merge your Sub New with the code in the one above.

End Class