public BrowseCallbackProc lpfn;

     <MarshalAs(UnmanagedType.FunctionPtr)>Public lpfn As BrowseCallbackProc

BrowseCallbackProc, BrowseInfoFlags

    /// If the user types an invalid name into the edit box, the browse dialog box calls the application's BrowseCallbackProc with the BFFM_VALIDATEFAILED message.

    ''' If the user types an invalid name into the edit box, the browse dialog box calls the application's BrowseCallbackProc with the BFFM_VALIDATEFAILED message.

public delegate int BrowseCallbackProc(IntPtr hwnd, int uMsg, IntPtr lParam, IntPtr lpData);

Public Delegate Function BrowseCallbackProc(hwnd As IntPtr, uMsg As Integer, lParam As IntPtr, lpData As IntPtr) As Integer

        // Constants for sending and receiving messages in BrowseCallBackProc

        public delegate int BrowseCallBackProc(IntPtr hwnd, int msg, IntPtr lp, IntPtr wp);

            public BrowseCallBackProc lpfn;

            bi.lpfn = new BrowseCallBackProc(OnBrowseEvent);

[Note from Adam: I just added 2 pages, so SHBrowseForFolder links to the BROWSEINFO structure, which links to the BrowseCallbackProc delegate used as one of its fields. The more that people can add stuff when they don't find it, we'll hopefully have fewer people feeling teased!]