FileHasChanges
- Updated2023-02-21
- 2 minute(s) read
FileHasChanges
LabWindows/CVI ActiveX Server Interface
CVI_AppFileHasChanges (CAObjHandle objectHandle, ERRORINFO *errorInfo, const char *pathname, long *hasChanges, long *returnValue);
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Note This function signature is shown as it appears when you create a client using the LabWindows/CVI ActiveX Controller Wizard. If you create a client for the LabWindows/CVI ActiveX server interface using a different development environment, this function might be exposed differently. Some of the parameters documented here, such as objectHandle or errorInfo, are not applicable if you write a client using a different development environment. |
Purpose
Determines whether the specified file has unsaved changes.
Parameters
| Input | ||
| Name | Type | Description |
| objectHandle | CAObjHandle | Specifier for a particular ActiveX object that is currently in memory. Obtain this handle from CVI_NewApp, CVI_OpenApp, CVI_ActiveApp, or an ActiveX method or property. All of the methods that you can apply to a particular object are grouped under a single class in the function tree. The name of the class corresponds to the type of the object to which this handle refers. |
| pathname | const char * | The absolute pathname of the file to evaluate. |
| Output | ||
| Name | Type | Description |
| errorInfo | ERRORINFO * | When an ActiveX server function fails with the error code DISP_E_EXCEPTION, descriptive information about the error code is stored in this parameter. The information can include the error code, source, and description. It also can include a help file and help file context ID. When an ActiveX server function fails with the error codes DISP_E_PARAMNOTFOUND, DISP_E_TYPEMISMATCH, or E_INVALIDARG, the parameter position of the invalid argument may be stored in the errorParamPos member of this parameter. You can pass NULL for this parameter. |
| hasChanges | long * | Indicates whether the specified file has unsaved changes. 0 = file does not have unsaved changes 1 = file has unsaved changes |
| returnValue | long * | The value that the LabWindows/CVI ActiveX server function returns. A negative value indicates that the LabWindows/CVI ActiveX server function returned an error. You can use GetCVIAutomationServerErrorString to get the description of a LabWindows/CVI ActiveX server error code. |
Return Value
| Name | Type | Description |
| status | HRESULT | A value indicating whether an error occurred. A negative error code indicates function failure. Error codes are defined in CVIversion\include\cviauto.h and <Program Files>\National Instruments\Shared\MSDTRedistributables\SDKHeaderFiles\8.1\winerror.h. You can use CA_GetAutomationErrorString to get the description of an ActiveX Library error code. |