GetContextPropertyValue function (recapis.h)

Article
10/05/2021

Returns a specified property value from the recognizer context.

Syntax

HRESULT GetContextPropertyValue(
  HRECOCONTEXT hrc,
  GUID         *pGuid,
  ULONG        *pcbSize,
  BYTE         *pProperty
);

Parameters

hrc

The handle to the recognizer context.

pGuid

The property to retrieve. Specify a predefined property globally unique identifier (GUID) or application-defined GUID. For a list of predefined properties, see the recognition Property GUIDs.

pcbSize

On input, the size, in bytes, the pProperty buffer can be. On output, the size, in bytes, the pProperty buffer is.

pProperty

The user allocated buffer to contain the property value. To determine the size of the buffer, set pProperty to NULL; use the size to allocate pProperty.

Return value

This function can return one of these values.

Return code	Description
S_OK	Success.
E_POINTER	One of the parameters is an invalid pointer.
E_FAIL	An unspecified error occurred.
E_INVALIDARG	An invalid argument was received.
TPC_E_UNINITIALIZED_PROPERTY	The property has not been set by the context. This may occur if the property is set only in certain circumstances, or if the property is to be set only after an event that has not yet occurred.
TPC_E_INVALID_PROPERTY	The recognizer does not support the property.
TPC_E_INSUFFICIENT_BUFFER	The pProperty buffer is too small.

Remarks

This function is optional.

You can use the GetContextPropertyValue function to get information that the recognizer is returning to the caller. This enables a customized recognizer to have modes and settings, and to return data that is unique to that recognizer.

In the Microsoft recognizers, calling the GetContextPropertyValue function with the pcbSize parameter set to a value larger than required does not result in an incorrect return value. Instead, the code automatically changes the size to the required value for the current GUID.

Requirements

Requirement	Value
Minimum supported client	Windows XP Tablet PC Edition [desktop apps only]
Minimum supported server	None supported
Target Platform	Windows
Header	recapis.h
DLL	inkobjcore.dll