IPrintCoreUI2::EnumFeatures method (prcomoem.h)
The IPrintCoreUI2::EnumFeatures method enumerates a printer's available features.
Syntax
HRESULT EnumFeatures(
[in] POEMUIOBJ poemuiobj,
[in] DWORD dwFlags,
[out] PZZSTR pmszFeatureList,
[in] DWORD cbSize,
[out] PDWORD pcbNeeded
);
Parameters
[in] poemuiobj
Pointer to the current context, an OEMUIOBJ structure.
[in] dwFlags
Is reserved and must be set to zero.
[out] pmszFeatureList
Pointer to a caller-supplied buffer that receives a null-delimited list of feature keywords in MULTI_SZ format. The list is terminated with two null characters.
Set this parameter to NULL to simply query for the size (*pcbNeeded) of the feature list without having the list filled in.
[in] cbSize
Specifies the size, in bytes, of the buffer pointed to by pmszFeatureList.
[out] pcbNeeded
Pointer to a memory location that receives the actual size, in bytes, of the feature list.
Return value
This method must return one of the following values.
| Return code | Description |
|---|---|
|
The method succeeded. |
|
The value in cbSize was smaller than the number of bytes to be written to the output buffer (the buffer pointed to by pmszFeatureList).
The method was called with pmszFeatureList set to NULL. |
|
The poemuiobj parameter pointed to an invalid context object. |
|
The method failed |
Remarks
This method is supported only for Windows XP Pscript5 plug-ins, not for Unidrv plug-ins.
printer-sticky features (see Replacing Driver-Supplied Property Sheet Pages), such as those that determine installable memory and the presence of optional accessories, are included in the feature keyword list, which appears in the output buffer pointed to by pmszFeatureList when the method returns. For Pscript5, such features have the OpenGroupType feature attribute set to "InstallableOptions".
To reduce the need to make two calls per data access, pass the method an output buffer of a fixed size (1 KB, for example), and then check the function return value. If the method returns S_OK, the buffer already contains the data of interest. If the method returns E_OUTOFMEMORY, the value in *pcbNeeded is the buffer size needed to hold the data of interest. The caller should then allocate a buffer of that larger size and proceed with a second call to the method.
For more information, see Using EnumFeatures.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Desktop |
| Header | prcomoem.h (include Prcomoem.h) |