Convert Boolean to Integer in VB.NET

Take the following code:

Sub Main()

    Dim i As Integer
    Dim b As Boolean

    i = 1
    b = i
    i = b
    Console.WriteLine(i)

    i = Convert.ToInt32(b)
    Console.WriteLine(i)

End Sub

This prints the following:

-1
1

Why is this?

(Just a joke :) You can get 0 too...

Int32.TryParse("True", i)
Console.WriteLine(i)