Allows a managed .NET class to unload an unmanaged DLL.

LibUnloader.cs

public class LibUnloader, IDisposable
{
  [DllImport("kernel32.dll")]
  private static extern bool FreeLibrary(IntPtr _HModule);
 
  [DllImport("kernel32.dll")]
  private static extern bool LoadLibraryA(string _HModule);
 
  [DllImport("kernel32.dll")]
  private static extern bool GetModuleHandleExA(UInt32 _Flags, string _ModuleName, ref IntPtr _HModule);

  private string ModuleName;
  private string LibName;

  LibUnloader(string _ModuleName)
  {
    ModuleName = _ModuleName;
    LibName = ModuleName+ ".dll";
    LoadLibraryA(LibName);
  }
  void Dispose()
  {
    IntPtr hMod = IntPtr.Zero;
    if (GetModuleHandleExA(0, ModuleName, ref hMod))
    {
      while (FreeLibrary(hMod));
    }
  }
}