Value of type 'Integer' cannot be converted to 'System.IntPtr'

I am receiving an error with a line of code I have learnt from a tutorials site (after converting it from C# to VB):
Dim thumb As System.Drawing.Image = image.GetThumbnailImage(CInt(Math.Truncate(imgWidth)), CInt(Math.Truncate(imgHeight)), Function() False, DirectCast(0, IntPtr))
The error relates to the "IntPtr" part, and reads:
"Value of type 'Integer' cannot be converted to 'System.IntPtr'"
Strangely, when this code was contained in a different class, there was no issue with it! I have imported the following:
Imports System.Collections Imports System.Collections.Specialized Imports System.Configuration Imports System.Text Imports System.Text.RegularExpressions Imports System.Web Imports System.Web.Caching Imports System.Web.SessionState Imports System.Web.Security Imports System.Web.Profile Imports System.Web.UI Imports System.Web.U ...