AssocQueryStringByKeyA function (shlwapi.h)
Searches for and retrieves a file association-related string from the registry starting from a specified key.
Syntax
LWSTDAPI AssocQueryStringByKeyA(
[in] ASSOCF flags,
[in] ASSOCSTR str,
[in] HKEY hkAssoc,
[in, optional] LPCSTR pszExtra,
[out, optional] LPSTR pszOut,
[in, out] DWORD *pcchOut
);
Parameters
[in] flags
Type: ASSOCF
The flags that can be used to control the search. It can be any combination of ASSOCF values, except that only one ASSOCF_INIT value can be included.
[in] str
Type: ASSOCSTR
The ASSOCSTR value that specifies the type of string that is to be returned.
[in] hkAssoc
Type: HKEY
The HKEY value of the key that will be used as a root key. The search looks only below this key.
[in, optional] pszExtra
Type: LPCTSTR
A pointer to an optional null-terminated string with additional information about the location of the string. It is normally set to a Shell verb such as open. Set this parameter to NULL if it is not used.
[out, optional] pszOut
Type: LPTSTR
A pointer to a null-terminated string used to return the requested string. Set this parameter to NULL to retrieve the required buffer size.
[in, out] pcchOut
Type: DWORD*
A pointer to a value that, on entry, specifies the number of characters in the pszOut buffer. When the function returns, it points to the number of characters placed in the buffer.
If the ASSOCF_NOTRUNCATE flag is set in flags and the buffer specified in pszOut is too small, the function returns E_POINTER and the value is set to the required size of the buffer.
If pszOut is NULL, the function returns S_FALSE and pcchOut points to the required size of the buffer.
Return value
Type: HRESULT
Returns a standard COM error value, including the following:
Error | Meaning |
---|---|
S_OK | Success. |
E_POINTER | The pszOut buffer is too small to hold the entire string. |
S_FALSE | pszOut is NULL. pcchOut contains the required buffer size. |
Remarks
This function is a wrapper for the IQueryAssociations interface. It is intended to simplify the process of using this interface. For further discussion of how the file association functions work, see IQueryAssociations.
Note
The shlwapi.h header defines AssocQueryStringByKey as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.
Requirements
Requirement | Value |
---|---|
Minimum supported client | Windows 2000 Professional, Windows XP [desktop apps only] |
Minimum supported server | Windows 2000 Server [desktop apps only] |
Target Platform | Windows |
Header | shlwapi.h |
Library | Shlwapi.lib |
DLL | Shlwapi.dll (version 5.0 or later) |