CA_VariantGetCStringBuf
HRESULT CA_VariantGetCStringBuf (VARIANT *variant, char buffer[], size_t bufferSize);
Purpose
Converts the BSTR string in the variant you specify into a C-style string and copies the string into a buffer parameter.
If buffer is not large enough to hold the string, CA_VariantGetCStringBuf copies (bufferSize - 1) characters into the buffer, followed by an ASCII NUL byte.
On success, CA_VariantGetCStringBuf releases the contents of the variant and marks it as empty.
CA_VariantGetCStringBuf returns an error if the variant does not contain a BSTR value.
Parameters
| Input | ||
| Name | Type | Description |
| bufferSize | size_t | Number of bytes in buffer. |
| Output | ||
| Name | Type | Description |
| variant | VARIANT | Pointer to a variant that contains a BSTR value. CA_VariantGetCStringBuf marks the variant as empty on success. |
| buffer | char [] | Buffer into which CA_VariantGetCStringBuf copies the C-style string it converts from the BSTR in the variant. |
Return Value
| Name | Type | Description |
| status | HRESULT | A value indicating whether an error occurred. Negative error codes indicate function failure. If the function succeeds, it returns a positive value representing the number of bytes, excluding the ASCII NUL byte, that it copied into the buffer. 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