Class C
    Implements IComparer
 
    Public Function Compare(ByVal x As Object, ByVal y As Object) As Integer _
      Implements IComparer.Compare
        Try
            Dim listElement As WallPaperProperties = CType(x, _
              WallPaperProperties)
            Dim searchElement As String = CStr(y)
 
            Return listElement.Wallpaper.CompareTo(searchElement)
        Catch ex As Exception
            Return -1
        End Try
    End Function
End Class

If arrayWallpaper.BinarySearch(filePath, New C) >= 0 Then
    ' Wallpaper in der Liste enthalten
    ...
End If