Marshal.GetLastWin32Error exposes the Win32 tp://go.microsoft.com/fwlink/?LinkId=148657 function from Kernel32.DLL. This method exists because it is not safe to make a direct platform invoke call to GetLastError to obtain this information. If you want to access this error code, you must call Marshal.GetLastWin32Error instead of writing your own platform invoke definition for GetLastError and calling it. The common language runtime can make internal calls to APIs that overwrite the GetLastError maintained by the operating system.

You can use this method to obtain error codes only if you apply the System.Runtime.InteropServices.DllImportAttribute to the method signature and set the DllImportAttribute.SetLastError field to true. The process for this varies depending upon the source language used: C# and C++ are false by default, but the Declare statement in Visual Basic is true.