Admin Production ni-theme
Current Publication

CA_VariantGetDouble

LabWindows/CVI

CA_VariantGetDouble

HRESULT CA_VariantGetDouble (const VARIANT *variant, double *value);

Purpose

Copies the value in a variant into a double-precision variable.

CA_VariantGetDouble returns an error if the variant does not contain a double-precision value.

Parameters

Input
Name Type Description
variant const VARIANT * Pointer to a variant that contains a double-precision value.
Output
Name Type Description
value double Double-precision value that CA_VariantGetDouble copies from the variant.

Return Value

Name Type Description
status HRESULT A value indicating whether an error occurred. Negative error codes indicate function failure.

Error codes are defined in CVIversion\include\cviauto.h and <Program Files>\National Instruments\Shared\MSDTRedistributables\SDKHeaderFiles\8.1\winerror.h. The LabWindows/CVI ActiveX Library explicitly returns error codes. Other error codes in winerror.h are generated by ActiveX servers and passed on to you by the LabWindows/CVI ActiveX Library.

You can use CA_GetAutomationErrorString to get the description of an error code or CA_DisplayErrorInfo to display the description of the error code.

Additional Information

Library: ActiveX Library

Include file: cviauto.h

LabWindows/CVI compatibility: LabWindows/CVI 5.0 and later

Example

Refer to userint\activex\3DGraphColorMap.cws for an example of using the CA_VariantGetDouble function.