DdeQueryStringW function (ddeml.h)
Copies text associated with a string handle into a buffer.
Syntax
DWORD DdeQueryStringW(
[in] DWORD idInst,
[in] HSZ hsz,
[out, optional] LPWSTR psz,
[in] DWORD cchMax,
[in] int iCodePage
);
Parameters
[in] idInst
Type: DWORD
The application instance identifier obtained by a previous call to the DdeInitialize function.
[in] hsz
Type: HSZ
A handle to the string to copy. This handle must have been created by a previous call to the DdeCreateStringHandle function.
[out, optional] psz
Type: LPTSTR
A pointer to a buffer that receives the string. To obtain the length of the string, this parameter should be set to NULL.
[in] cchMax
Type: DWORD
The length, in characters, of the buffer pointed to by the psz parameter. For the ANSI version of the function, this is the number of bytes; for the Unicode version, this is the number of characters. If the string is longer than ( cchMax– 1), it will be truncated. If the psz parameter is set to NULL, this parameter is ignored.
[in] iCodePage
Type: int
The code page used to render the string. This value should be either CP_WINANSI or CP_WINUNICODE.
Return value
Type: DWORD
If the psz parameter specified a valid pointer, the return value is the length, in characters, of the returned text (not including the terminating null character). If the psz parameter specified a NULL pointer, the return value is the length of the text associated with the hsz parameter (not including the terminating null character). If an error occurs, the return value is 0L.
Remarks
The string returned in the buffer is always null-terminated. If the string is longer than ( cchMax– 1), only the first ( cchMax– 1) characters of the string are copied.
If the psz parameter is NULL, the DdeQueryString function obtains the length, in bytes, of the string associated with the string handle. The length does not include the terminating null character.
Note
The ddeml.h header defines DdeQueryString as an alias that 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 is 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 [desktop apps only] |
| Minimum supported server | Windows 2000 Server [desktop apps only] |
| Target Platform | Windows |
| Header | ddeml.h (include Windows.h) |
| Library | User32.lib |
| DLL | User32.dll |
See also
Conceptual
Dynamic Data Exchange Management Library
Reference