wiasSetItemPropAttribs function (wiamdef.h)

Article
03/13/2023

The wiasSetItemPropAttribs function sets the access flags and valid values for an item's set of properties.

Syntax

HRESULT wiasSetItemPropAttribs(
  [in] BYTE               *pWiasContext,
       LONG               cPropSpec,
  [in] PROPSPEC           *pPropSpec,
  [in] PWIA_PROPERTY_INFO pwpi
);

Parameters

[in] pWiasContext

Pointer to a WIA item context.

cPropSpec

Specifies the number of properties.

[in] pPropSpec

Pointer to the first element of an array of PROPSPEC structures (defined in the Microsoft Windows SDK documentation) indicating the properties for which to set valid values and access flags.

[in] pwpi

Pointer to the first element of an array of WIA_PROPERTY_INFO structures that contain the property values to be written.

Return value

On success, the function returns S_OK. If the function fails, it returns a standard COM error or one of the WIA_ERROR_XXX errors (described in the Windows SDK documentation).

Remarks

Minidrivers should use this function to initialize groups of simple properties. The groups of properties can be bitsets, ranges of values, or lists of values. The supported simple types, grouped by attribute are as follows.

Attributes	Supported Types
WIA_PROP_FLAG	VT_UI1, VT_UI2, VT_UI4, VT_UI8, VT_I1, VT_I2, VT_I4, VT_I8
WIA_PROP_RANGE	VT_UI1, VT_UI2, VT_UI4, VT_UI8, VT_I1, VT_I2, VT_I4, ,VT_I8, VT_R4, VT_R8
WIA_PROP_LIST	VT_UI1, VT_UI2, VT_UI4, VT_UI8, VT_I1, VT_I2, VT_I4, ,VT_I8, VT_R4, VT_R8, VT_BSTR

Minidrivers should initialize complex properties using the wiasSetPropertyAttributes function.

The minidriver can set the WIA_PROP_CACHEABLE flag on a property that does not change over time. By setting this flag on a property, the minidriver indicates that the WIA service can cache the property value. See the Windows SDK documentation for a list of all property attributes.

It is important to remember that wiasSetItemPropAttribs returns an HRESULT, not a BOOLEAN. For example, if wiasSetItemPropAttribs returns 0, this value must be interpreted as S_OK rather than FALSE, and indicates that everything worked as expected. If wiasSetItemPropAttribs returns the HRESULT S_FALSE, this indicates that one of the properties you are trying to set probably does not exist in the property stream.

To get a wiadebug log of this error, open the registry and turn on WIA logging for Warnings and Errors. The registry key for this is: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StillImage\Debug\wiaservc.dll

Set the value of "DebugFlags." to 0x00000003

Reboot the system and repeat the steps necessary to produce this error. There will now be a file named "wiadebug.log" in %windir% directory.

Requirements

Requirement	Value
Target Platform	Desktop
Header	wiamdef.h (include Wiamdef.h)
Library	Wiaservc.lib
DLL	Wiaservc.dll