C / C++ / MFC

maxMESA wrote:

My question is how can i load this dll in my activex. I am using LoadLibrary(x.dll) and it searches for dll in windows/system32 folder.

std::string GetThisModulesFileName()
{
   HMODULE hMod;
   char path[MAX_PATH];
   GetModuleHandleExA(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS, reinterpret_cast<lpcstr>(&GetThisModulesFileName), &hMod);
   GetModuleFileNameA(hMod, path, MAX_PATH);
   return std::string(path);
}</lpcstr>

sharion wrote:

About the result, one explanation is p in function GetMemory is only a copy of variable str. This explanation may be right but it seems that it contradicts pass by reference. Now that passing by reference, where is the copy come from. And operations done to variable p is equal to operations to str,why str is NULL finally.

void GetMemory(char** p)
	{
		*p =  new char[100];
	}
int main()
{
   char* str = NULL;
   GetMemory(&str);
   /* */
}

void GetMemory(char*& p)
	{
		p =  new char[100];
	}
int main()
{
   char* str = NULL;
   GetMemory(str);
   /* */
}

Stuart Dootson wrote:

When you pass a pointer, the thing that is pointed at is passed by reference.

void GetMemory(char* p)
{
    p =  new char[100];
    *(p + 10) = 'a'; /* following comment is true or not?*/
                     /* operate to the memory block 
                        that you called passed by reference
                     */
}
int main()
{
   char* str = NULL; 
   GetMemory(str);
   /* */}

char* str = NULL;   // str is a char pointer, set to NULL
GetMemory(str);
     void GetMemory(char* p)  // p is a char pointer set to NULL
     p =  new char[100];      // the old p is overwritten by a new pointer, pointing to a 100 byte buffer
     *(p + 10) = 'a';         // the new p is used to write some into that buffer
     return;
... // back from GetMemory    // str has never been changed

void GetMemory(char** p)    // accept pointer to pointer to char
{
    p =  new char[100];
}
int main()
{
   char* str = NULL; 
   GetMemory(&str);   // pass the address of str (=pointer to pointer)
   // str will have changed now

sharion wrote:

*(p + 10) = 'a'; /* following comment is true or not?*/
/* operate to the memory block
that you called passed by reference
*/

p =  new char[100];

sharion wrote:

We believe str is still NULL, where I have mistaken?

sharion wrote:

Based on experience previous, I take it for granted that whatever you have done to p have the same effect to str. That is passing by reference what I previously thought

int Double(int x)
{
   return x + x;
}

int Double(int *pX)
{
   return (*pX) + (*pX);
}

int StringLength(char* s)
{
   int length = 0;
   while (*(s + length) != 0)
      ++length;
}

Luc Pattyn wrote:

Is it still in active use?

Luc Pattyn wrote:

is there an ADA#?

Luc Pattyn wrote:

should we have a forum on it?

void GetMemory(char* p)
	{
		if(p != NULL)
		{
			delete []p;
			p = NULL;
		}
		if(p == NULL)
		{
			p =  new char[1000];
			*(p+10) = 'a';
		}
	}
int main()
{
char* str = NULL;
str = new char[100];
GetMemory(str);
/* */
}

sharion wrote:

Above code snippet indicates that before and after GetMemory(str);point str is being revised.I have no idea why such happens.

int main()
{
   char* str = NULL;
   str = new char[100];
   std::cout << (int)str <<std::endl;
   GetMemory(str);
   std::cout << (int)str <<std::endl;
/* */
}