Error in my calling Function

this is my code

public delegate void NotifyFunc(enumType notificationType, IntPtr data); 

[DllImport("VssSdkd")] 
public static extern void startVssSdkClientEcho(string IpAddress, 
    long port, NotifyFunc notifyFunc, eProtocolType proType, bool Req); 

am call the function like

CallBack calbck = new CallBack(TestDllImport.Callbackas);

开发者_JAVA技巧startVssSdkClientEcho("192.168.10.240", 12050, calbck, TestDllImport.eProtocolType.eProtocolType_VssSdk, false);

here my receving callback function is

static public void Callbackas(eNotificationType type, IntPtr datas) {}

here first time am receving data and then it's giving Error msg like :

run time check failure #0 - the value if ESP was not properly saved across a function call.
 this is usually a result of calling a function declared with one calling convention 
with a function pointer declared with a different calling convention 

please help me to identify my error... thanks in advance

---

Is this your code you are calling (sorry cursory search could only find your other post referring to startVssSdkClientEcho). Is it decalred cdecl (i.e. it has no __declspec at all) or is it stdcall. If it is cdecl you need to add CallingConvention attribute to the DllImport

i.e.

[DllImport("VssSdkd", CallingConvention=CallingConvention.Cdecl)]

Of course it might also be the callback calling convention at fault which is another issue.