Error while declaring Interfaces regarding HRESULT

[giji gangadharan]

Error : "The type or namespace HRESULT could not be found(are you missing a using directive or an assembly reference)" Code Snippet using System; using System.Runtime.CompilerServices; using System.Runtime.InteropServices; using System.Runtime.InteropServices.ComTypes; using System.Text; [ ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid(IIDGuid.EnumIdList), ] internal interface IEnumIDList { [PreserveSig()] HRESULT Next(uint celt, out IntPtr rgelt, out int pceltFetched); [PreserveSig()] HRESULT Skip(uint celt); void Reset(); void Clone([Out, MarshalAs(UnmanagedType.Interface)] out IEnumIDList ppenum); } Please help...

[Ben Fair]

For C#'s COM Interop HRESULT will be returned as uint when using the PreserveSig(true) attribute. Change the method signatures in your interface of the two methods that return HRESULT to return uint instead and you should be good to go. You can also go a step further and create a uint enum that defines the possible result values:

public enum Next_HRESULTs : uint
{
S_OK 0x...,
...
}

public enum Skip_HRESULTs : uint
{
S_OK 0x...,
...
}

Hold on a second here... Don't you think you might be putting the horse ahead of the cart?