C#清除WebBrowser中Cookie缓存的方法

[DllImport("wininet.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto, SetLastError = true)]public static extern bool InternetSetOption(int hInternet, int dwOption, IntPtr lpBuffer, int dwBufferLength);private unsafe void SuppressWininetBehavior(){  /* SOURCE: http://msdn.microsoft.com/en-us/library/windows/desktop/aa385328%28v=vs.85%29.aspx  * INTERNET_OPTION_SUPPRESS_BEHAVIOR (81):  *   A general purpose option that is used to suppress behaviors on a process-wide basis.   *   The lpBuffer parameter of the function must be a pointer to a DWORD containing the specific behavior to suppress.   *   This option cannot be queried with InternetQueryOption.   *     * INTERNET_SUPPRESS_COOKIE_PERSIST (3):  *   Suppresses the persistence of cookies, even if the server has specified them as persistent.  *   Version: Requires Internet Explorer 8.0 or later.  */  int option = (int)3/* INTERNET_SUPPRESS_COOKIE_PERSIST*/;  int* optionPtr = &option;  bool success = InternetSetOption(0, 81/*INTERNET_OPTION_SUPPRESS_BEHAVIOR*/, new IntPtr(optionPtr), sizeof(int));  if (!success)  {    MessageBox.Show("Something went wrong !>?");  }}