Why can’t "If" verify equality between Ctype(double, int32) with int32?

Question

I have a function that returns me a Double and need to check if the result is equal to 5000. I am using If CType(resultadoFunção as double, Int32) = 5000 Then, but though he shows 5000, he does not return True. Why?

 Private Async Sub Teste1()
    'Necessário Engucv
    'Imports Emgu.CV

    'vid = caminho de algum video
    Capiture = New VideoCapture(vid)

    While True
        Dim m As New Mat
        Capiture.Read(m)
        PictureBox1.Image = m.Bitmap
        Label1.Text = CType(Capiture.GetCaptureProperty(CvEnum.CapProp.PosMsec), Int32).ToString
        Await Task.Delay(42)

        If CType(Capiture.GetCaptureProperty(CvEnum.CapProp.PosMsec), Int32) = 5000 Then
            'Faz algo
        End If
    End While
End Sub

Answer 1

This is because the type Double has no accuracy and to be equal needs to be exactly equal, a minimum difference is not acceptable, it is already different. You can see more details on What is the correct way to use the float, double and decimal types?. At the moment that makes this conversion is probably generating a number like 4999.99999999998 and there the whole part is 4999, therefore different from 5000. The use of a Round() can solve the problem in this case, but beware of others.