how to call a function in m ain from my unmanged dll with pointer as parameter

See more:

C#2.0

C#

please help me
i have a function say :----

EXPORT_IMPORT int __cdecl getDevices ( char ** pDeviceList, int * pDeviceCount ,unsigned long ulFlags ) this is in c++
i m working in c# and want to import dll and need to call function in my main from my unmanged dll.
please note that i have to pass parametrs while calling function in main accrding to the parameterts which i have mention in my function prototype above
so just send me the whole code to call this function.
i have code to import my dll just ahve a look on it--

[DllImport(@"C:\WINDOWS\WinSxS\unmanged.dll", SetLastError = true)]
public static unsafe extern int getDevices(char ** pDeviceList, int * pDeviceCount, uint ulFlags);

i m sucessfully able to import my dll but not able to call function i m getting error

Error 1 The best overloaded method match for 'ConsoleApplication2.getDevices() has some invalid arguments


Error 2 Argument '1': cannot convert from 'char**' to 'ref System.Text.StringBuilder'

Error 3 Argument '2': cannot convert from 'int*' to 'System.IntPtr'

when i pass these parametrts
let say getDevice(ref StringBuilder pDeviceList, IntPtr pDeviceCount, ulong ulFlags);

tell me what parametrs i have to pass from my function equivalent to this arguments while calling function in main from my unmanaged dll.
please note that i need to know what parametrs i have to pass from my function in order to call my function.
because i have several function with parametrs of different data types.
so please let me know sir abt it as soon as possible.

Aasif Eqbal Aslam
aasifaslamy85@gmail.com