Convert CString to DWORD
Question
Friday, October 31, 2014 12:35 PM
I have follow CString:
CString sTemp(_T("20120827114308"));
and I want to convert to DWORD ... and I had tried in foloow way:
DWORD dwBuffer = (DWORD)sTemp.GetBuffer(sTemp.GetLength());
but result is:
5787108
why ?
All replies (6)
Friday, October 31, 2014 2:17 PM âś…Answered
Now I am searching CString to unsigned int64 ... but as I am using VC6, I don't have so much possibilities ...
I believe VC6 supports __int64 and unsigned __int64, and also _atoi64.
David Wilkinson | Visual C++ MVP
Friday, October 31, 2014 1:09 PM
I have follow CString:
CString sTemp(_T("20120827114308"));and I want to convert to DWORD ... and I had tried in foloow way:
DWORD dwBuffer = (DWORD)sTemp.GetBuffer(sTemp.GetLength());but result is:
5787108
why ?
What do expect to happen? What is the purpose of this conversion?
CString::GetBuffer() returns a TCHAR* pointer to a nul-terminated string, so the DWORD conversion is just the value of the address.
If you want to treat the value 20120827114308 as a DWORD you should realize that this value is too big to fit in a DWORD (which is unsigned int -- 32 bits).
David Wilkinson | Visual C++ MVP
Friday, October 31, 2014 1:33 PM
I tried this too:
DWORD dwBuffer = _tcstoul(sTemp, 0, 10);
result: -1.
Friday, October 31, 2014 1:41 PM
I tried this too:
DWORD dwBuffer = _tcstoul(sTemp, 0, 10);result: -1.
From the documentation
strtoul returns the converted value, if any, or ULONG_MAX on overflow
On Windows, ULONG_MAX is hexadecimal 0xFFFFFFFF, which is -1 if viewed as a signed integer.
As I told you, 20120827114308 is too big to fit in a 32-bit integer (either signed or unsigned). You need a 64-bit type to hold this value.
David Wilkinson | Visual C++ MVP
Friday, October 31, 2014 1:53 PM
Now I am searching CString to unsigned int64 ... but as I am using VC6, I don't have so much possibilities ...
Monday, November 3, 2014 8:47 AM
I solved in this way:
unsigned __int64 ui64;
_stscanf((LPCTSTR)sTemp, _T("%I64u"), &ui64);