error C2664: 'SetDlgItemTextW' : cannot convert parameter 3 from 'SYSTEMTIME' to 'LPCWSTR' 208

Question

I still have some trouble with understanding this with UNICODE and ANSI in win32 api..

For example, i have this code:

SYSTEMTIME LocalTime = { 0 };
GetSystemTime (&LocalTime);
SetDlgItemText(hWnd, 1003, LocalTime);'

That generates the error in the title.

Also, i should mention that it automatically adds a W after "setdlgitemtext" Some macro in VS probably.

Could someone clarify this for me?

Answer 1

In C or C++ you can't just take an arbitrary structure and pass it to a function that expects a string. You have to convert that structure to a string first.

The Win32 functions GetDateFormat() and GetTimeFormat() can be used to convert a SYSTEMTIME to a string (the first one does the "date" part and the second one does the "time" part) according to the current system locale rules.

For example,

SYSTEMTIME LocalTime = { 0 };
GetSystemTime (&LocalTime);
wchar_t wchBuf[80];
GetDateFormat(LOCALE_USER_DEFAULT, DATE_SHORTDATE, &LocalTime, NULL, wchBuf, sizeof(wchBuf) / sizeof(wchBuf[0]));
SetDlgItemText(hWnd, 1003, wchBuf);