Calling C++ dll by using C# wrapper method , Exception occures

Question

I am facing a problem while using the ITMSDLL.

 

 

The following is the C# code defined in my  Application

 

public static string Get_Month_Mask(string theByt,int theMon, string theYr)
        {
            string aMByte = theByt;
            int aSt_Dow, aEn_Dow, aSt_Wk, aEn_Wk;
            DateTime aSDate = new DateTime(Convert.ToInt32(theYr),Convert.ToInt32(theMon),01);
            DateTime aEDate = aSDate.AddMonths(1).AddDays(-1.0);
            string aRetMask = "X".PadRight(120);
            int aRc;
            aSt_Dow = Utility.GetDayNumber(aSDate.DayOfWeek.ToString());
            aEn_Dow = Utility.GetDayNumber(aEDate.DayOfWeek.ToString());
            aSt_Wk = Utility.GetWeekOfTheYear(aSDate);
            aEn_Wk = Utility.GetWeekOfTheYear(aEDate);
            aRc = Utility.objCITMSDLL.GetMonthMask(out aRetMask,out aMByte, aSt_Dow, aSt_Wk, aEn_Dow, aEn_Wk);
            return aRetMask.ToString();
        }

 

 

And the below is the code used in ITMSDOTNETDLL where the wrapper method is written.

 

 

[DllImport("ITMSDLL.dll")]

internal static extern int get_month_mask(out string theMask,out string theByt, int theSt_Dow, int theSt_Week, int theEn_Dow, int theEn_Week);

 

public int GetMonthMask(out string theMask,out string theByt, int theSt_Dow, int theSt_Week, int theEn_Dow, int theEn_Week)

{

return CITMSDLLMethods.get_month_mask(out theMask, out theByt, theSt_Dow, theSt_Week, theEn_Dow, theEn_Week);

}

it throws error

 

The runtime has encountered a fatal error. The address of the error was at 0x79e71bd7, on thread 0xc94. The error code is 0xc0000005. This error may be a bug in the CLR or in the unsafe or non-verifiable portions of user code. Common sources of this bug include user marshaling errors for COM-interop or PInvoke, which may corrupt the stack.

 

if we use "ref" instead of "out" then it also throws same(above) error.

 

 

If anybody can help then please help me.