IXpsOMPage::GenerateUnusedLookupKey method (xpsobjectmodel.h)

Article
02/22/2024

Generates a unique name that can be used as a lookup key by a resource in a resource dictionary.

Syntax

HRESULT GenerateUnusedLookupKey(
  [in]          XPS_OBJECT_TYPE type,
  [out, retval] LPWSTR          *key
);

Parameters

[in] type

The type of IXpsOMShareable object for which the lookup key is generated.

[out, retval] key

The lookup key string that is generated by this method.

Return value

If the method succeeds, it returns S_OK; otherwise, it returns an HRESULT error code.

Return code	Description
S_OK	The method succeeded.
E_POINTER	key is NULL.
E_INVALIDARG	type refers to an object type that is not recognized.

Remarks

To be unique in the dictionary, the string generated by GenerateUnusedLookupKey consists of a prefix string that is based on the object type and is followed by four unique alphanumeric characters.

The prefix string for each object type is shown in the following table.

Object type	Prefix string for this object type
XPS_OBJECT_TYPE_CANVAS	Canvas_
XPS_OBJECT_TYPE_GEOMETRY	Geometry_
XPS_OBJECT_TYPE_GLYPHS	Glyphs_
XPS_OBJECT_TYPE_IMAGE_BRUSH	IBrush_
XPS_OBJECT_TYPE_LINEAR_GRADIENT_BRUSH	LGBrush_
XPS_OBJECT_TYPE_MATRIX_TRANSFORM	MTransform_
XPS_OBJECT_TYPE_PATH	Path_
XPS_OBJECT_TYPE_RADIAL_GRADIENT_BRUSH	RGBrush_
XPS_OBJECT_TYPE_SOLID_COLOR_BRUSH	SCBrush_
XPS_OBJECT_TYPE_VISUAL_BRUSH	VBrush_

Note

This method returns a key string that is unique within the context of this page. It is not guaranteed to return a key that is unique in a remote dictionary resource that could be used by more than one page.

This method allocates the memory used by the string that is returned in key. If key is not NULL, use the CoTaskMemFree function to free the memory.

Requirements

Requirement	Value
Minimum supported client	Windows 7, Windows Vista with SP2 and Platform Update for Windows Vista [desktop apps \| UWP apps]
Minimum supported server	Windows Server 2008 R2, Windows Server 2008 with SP2 and Platform Update for Windows Server 2008 [desktop apps \| UWP apps]
Target Platform	Windows
Header	xpsobjectmodel.h