What is IntPtr???

The IntPtr type is designed to be an integer whose size is platform-specific. That is, an instance of this type is expected to be 32-bits on 32-bit hardware and operating systems, and 64-bits on 64-bit hardware and operating systems.

The IntPtr type can be used by languages that support pointers, and as a common means of referring to data between languages that do and do not support pointers.

IntPtr objects can also be used to hold handles. For example, instances of IntPtr are used extensively in the System.IO.FileStream class to hold file handles.

The IntPtr type is CLS-compliant, while the UIntPtr type is not. Only the IntPtr type is used in the common language runtime. The UIntPtrtype is provided mostly to maintain architectural symmetry with the IntPtr type.

A platform-specific type that is used to represent a pointer or a handle.

The IntPtr type is designed to be an integer whose size is platform-specific. That is, an instance of this type is expected to be 32-bits on 32-bit hardware and operating systems, and 64-bits on 64-bit hardware and operating systems.
The IntPtr type can be used by languages that support pointers, and as a common means of referring to data between languages that do and do not support pointers.

Download the sample by :
http://cid-fd3332cdd86da8fa.skydrive.live.com/self.aspx/Public/TestinIntPtr.rar

refer to MSDN.
http://msdn.microsoft.com/en-us/library/system.intptr(VS.71).aspx