list of VARIANT

bojinyu

I want do built a list of VARIANT #include typedef std::list VARIANTLIST; VARIANTLIST varList; and I add a VARIANT into list varList; VARIANT pp; pp.vt=VT_I2; pp.iVal=1; varList.push_back(pp); then length of vatList is increased 1, but the comment is not right. What is the matter? Can you help me, Thanks.

Daniel Strigl

What do you mean with "then length of vatList is increased 1, but the comment is not right"? Daniel ;) --------------------------- Never change a running system!

bojinyu

Sorry, I spell a word wrong. I means then sizes of varList si increased 1, and now varList.size() return 1. but the element VARIANT whose vt is not VT_I2.

bojinyu

Sorry, I spell a word wrong. I means then sizes of varList si increased 1, and now varList.size() return 1. but the element VARIANT whose vt is not VT_I2.

Daniel Strigl

Sorry, but I think I don't understand :omg: :-O !!! I have tested your code:

// variant.cpp : Definiert den Einsprungpunkt für die Konsolenanwendung.
//

#include "stdafx.h"
#include <atlbase.h>
#include <list>

typedef std::list<VARIANT> VARIANTLIST;
VARIANTLIST varList;

int main(int argc, char* argv[])
{
for (int n = 0; n < 100; n++)
{
VARIANT var;
var.vt = VT_I2;
var.iVal = 1;

    varList.push\_back(var);
}

printf("size = %d \\n", (int) varList.size());

return 0;

}

There is all right with the code! I have a std::list of VARIANT and add 100 members of VARIANT to the list! The varList.size() function returns the count of elements in the list and so it returns 100 and that's right! The VT_I2 says that the VARIANT holds short members. I2 says that the member is an integer who need 2 byte of space in the memory (sizeof(short) = 2). Take a look in the MSDN:

typedef struct tagVARIANT {
VARTYPE vt;
unsigned short wReserved1;
unsigned short wReserved2;
unsigned short wReserved3;
union {
Byte bVal; // VT_UI1.
Short iVal; // VT_I2. <===== LOOK HERE !!!
long lVal; // VT_I4.
float fltVal; // VT_R4.
double dblVal; // VT_R8.

  ...
  ...
  ...

};
};

Hope this helps you! Daniel ;) --------------------------- Never change a running system!

bojinyu

Thanks Daniel S. I have remove the problem. All the code really run in the right way, the fault was my wrong checking. I check by the watch window of Visual Stdio. The results of the list element showed there are upset. Thanks again.