Why does Microsoft's code examples have errors, and how do I fix these?

Question

The code examples on this page all seem to have errors, some of which I don't have a clue how to fix.

How do I fix the following:

code:

hResult = StringCchLength(pmyitem->psz, STRSAFE_MAX_CCH, pcch);

error:

argument of type "LPSTR"is incompatible with parameter of "STRSAFE_PCNZWCH"

code:

GetTextExtentPoint32(hdc, pmyitem->psz, *pcch, &size);
ExtTextOut(
	lpdis->hDC, 
	nTextX, 
	nTextY, 
	ETO_OPAQUE, 
	&lpdis->rcItem, 
	pmyitem->psz, 
	*pcch, NULL
);

error:

argument of type "LPSTR"is incompatible with parameter of "LPCWSTR"

Answer 1

Windows API functions usually have two versions. There is a "W" version when building for UNICODE and an "A" version for non-UNICODE builds. For example, when building for UNICODE the compiler sees a function named ExtTextOutW which expects wide-character strings. However, the example code declares some variables as LPSTR which means it is a pointer to a narrow string. This causes the compiler errors.

The simplest solution is to change the character set that you are building for to either "Not Set" or MBCS. That should eliminate the kinds of errors you have described.

Answer 2

Use WCHAR (LPTSTR) everywhere :

typedef struct _MYITEM
{
	HFONT hfont;
	LPTSTR psz;
} MYITEM;   

Answer 3

Hi, @CDev-8220

The sample uses ANSI. StringCchLengthA and GetTextExtentPoint32A
Set MBCS or use wchar

Best regards,

Minxin Yu

---

If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.