Interface OleAuto

    • Field Detail

      • INSTANCE

        static final OleAuto INSTANCE
        The instance.
      • DISPATCH_METHOD

        static final int DISPATCH_METHOD
        The Constant DISPATCH_METHOD.
        See Also:
        Constant Field Values
      • DISPATCH_PROPERTYGET

        static final int DISPATCH_PROPERTYGET
        The Constant DISPATCH_PROPERTYGET.
        See Also:
        Constant Field Values
      • DISPATCH_PROPERTYPUT

        static final int DISPATCH_PROPERTYPUT
        The Constant DISPATCH_PROPERTYPUT.
        See Also:
        Constant Field Values
      • DISPATCH_PROPERTYPUTREF

        static final int DISPATCH_PROPERTYPUTREF
        The Constant DISPATCH_PROPERTYPUTREF.
        See Also:
        Constant Field Values
      • FADF_AUTO

        static final int FADF_AUTO
        An array that is allocated on the stac.
        See Also:
        Constant Field Values
      • FADF_STATIC

        static final int FADF_STATIC
        An array that is statically allocated.
        See Also:
        Constant Field Values
      • FADF_EMBEDDED

        static final int FADF_EMBEDDED
        An array that is embedded in a structure.
        See Also:
        Constant Field Values
      • FADF_FIXEDSIZE

        static final int FADF_FIXEDSIZE
        An array that is embedded in a structure.
        See Also:
        Constant Field Values
      • FADF_RECORD

        static final int FADF_RECORD
        An array that is embedded in a structure.
        See Also:
        Constant Field Values
      • FADF_HAVEIID

        static final int FADF_HAVEIID
        An array that is embedded in a structure.
        See Also:
        Constant Field Values
      • FADF_HAVEVARTYPE

        static final int FADF_HAVEVARTYPE
        An array that has a variant type. The variant type can be retrieved with SafeArrayGetVartype.
        See Also:
        Constant Field Values
      • FADF_RESERVED

        static final int FADF_RESERVED
        Bits reserved for future use.
        See Also:
        Constant Field Values
      • VARIANT_ALPHABOOL

        static final short VARIANT_ALPHABOOL
        For VT_BOOL to VT_BSTR conversions, convert to "True"/"False" instead of "-1"/"0"
        See Also:
        Constant Field Values
      • VARIANT_NOUSEROVERRIDE

        static final short VARIANT_NOUSEROVERRIDE
        For conversions to/from VT_BSTR, passes LOCALE_NOUSEROVERRIDE to core coercion routines
        See Also:
        Constant Field Values
      • VARIANT_LOCALBOOL

        static final short VARIANT_LOCALBOOL
        For VT_BOOL to VT_BSTR and back, convert to local language rather than English
        See Also:
        Constant Field Values
      • VARIANT_CALENDAR_THAI

        static final short VARIANT_CALENDAR_THAI
        SOUTHASIA calendar support
        See Also:
        Constant Field Values
      • VARIANT_CALENDAR_GREGORIAN

        static final short VARIANT_CALENDAR_GREGORIAN
        SOUTHASIA calendar support
        See Also:
        Constant Field Values
      • VARIANT_USE_NLS

        static final short VARIANT_USE_NLS
        NLS function call support
        See Also:
        Constant Field Values
    • Method Detail

      • SysAllocString

        WTypes.BSTR SysAllocString​(String sz)
        This function allocates a new string and copies the passed string into it.
        Parameters:
        sz - Null-terminated UNICODE string to copy.
        Returns:
        Null if there is insufficient memory or if a null pointer is passed in.
      • SysFreeString

        void SysFreeString​(WTypes.BSTR bstr)
        This function frees a string allocated previously by SysAllocString, SysAllocStringByteLen, SysReAllocString, SysAllocStringLen, or SysReAllocStringLen.
        Parameters:
        bstr - Unicode string that was allocated previously, or NULL. Setting this parameter to NULL causes the function to simply return.
      • SysStringByteLen

        int SysStringByteLen​(WTypes.BSTR bstr)
        Returns the length (in bytes) of a BSTR.
        Parameters:
        bstr - Unicode string that was allocated previously.
      • SysStringLen

        int SysStringLen​(WTypes.BSTR bstr)
        Returns the length of a BSTR.
        Parameters:
        bstr - Unicode string that was allocated previously.
      • VariantInit

        void VariantInit​(Variant.VARIANT.ByReference pvarg)
        The VariantInit function initializes the VARIANTARG by setting the vt field to VT_EMPTY. Unlike VariantClear, this function does not interpret the current contents of the VARIANTARG. Use VariantInit to initialize new local variables of type VARIANTARG (or VARIANT).
        Parameters:
        pvarg - The variant to initialize.
      • VariantInit

        void VariantInit​(Variant.VARIANT pvarg)
        The VariantInit function initializes the VARIANTARG by setting the vt field to VT_EMPTY. Unlike VariantClear, this function does not interpret the current contents of the VARIANTARG. Use VariantInit to initialize new local variables of type VARIANTARG (or VARIANT).
        Parameters:
        pvarg - The variant to initialize.
      • VariantCopy

        WinNT.HRESULT VariantCopy​(Pointer pvargDest,
                                  Variant.VARIANT pvargSrc)
        First, free any memory that is owned by pvargDest, such as VariantClear (pvargDest must point to a valid initialized variant, and not simply to an uninitialized memory location). Then pvargDest receives an exact copy of the contents of pvargSrc.

        If pvargSrc is a VT_BSTR, a copy of the string is made. If pvargSrcis a VT_ARRAY, the entire array is copied. If pvargSrc is a VT_DISPATCH or VT_UNKNOWN, AddRef is called to increment the object's reference count.

        If the variant to be copied is a COM object that is passed by reference, the vtfield of the pvargSrcparameter is VT_DISPATCH | VT_BYREF or VT_UNKNOWN | VT_BYREF. In this case, VariantCopy does not increment the reference count on the referenced object. Because the variant being copied is a pointer to a reference to an object, VariantCopy has no way to determine if it is necessary to increment the reference count of the object. It is therefore the responsibility of the caller to call IUnknown::AddRef on the object or not, as appropriate.

        Note The VariantCopy method is not threadsafe.

        Parameters:
        pvargDest - [out] The destination variant.
        pvargSrc - [in] The source variant.
        Returns:
        the hresult
      • VariantClear

        WinNT.HRESULT VariantClear​(Variant.VARIANT pvarg)
        Use this function to clear variables of type VARIANTARG (or VARIANT) before the memory containing the VARIANTARG is freed (as when a local variable goes out of scope).

        The function clears a VARIANTARG by setting the vt field to VT_EMPTY. The current contents of the VARIANTARG are released first. If the vtfield is VT_BSTR, the string is freed. If the vtfield is VT_DISPATCH, the object is released. If the vt field has the VT_ARRAY bit set, the array is freed.

        If the variant to be cleared is a COM object that is passed by reference, the vtfield of the pvargparameter is VT_DISPATCH | VT_BYREF or VT_UNKNOWN | VT_BYREF. In this case, VariantClear does not release the object. Because the variant being cleared is a pointer to a reference to an object, VariantClear has no way to determine if it is necessary to release the object. It is therefore the responsibility of the caller to release the object or not, as appropriate.

        In certain cases, it may be preferable to clear a variant in code without calling VariantClear. For example, you can change the type of a VT_I4 variant to another type without calling this function. Safearrays of BSTR will have SysFreeString called on each element not VariantClear. However, you must call VariantClear if a VT_type is received but cannot be handled. Safearrays of variant will also have VariantClear called on each member. Using VariantClear in these cases ensures that code will continue to work if Automation adds new variant types in the future.

        Do not use VariantClear on unitialized variants; use VariantInit to initialize a new VARIANTARG or VARIANT.

        Variants containing arrays with outstanding references cannot be cleared. Attempts to do so will return an HRESULT containing DISP_E_ARRAYISLOCKED.

        Parameters:
        pvarg - [in, out] The variant to clear.
        Returns:
        the hresult
      • VariantChangeType

        WinNT.HRESULT VariantChangeType​(Variant.VARIANT pvargDest,
                                        Variant.VARIANT pvarSrc,
                                        short wFlags,
                                        WTypes.VARTYPE vt)
        Converts a variant from one type to another.
        Parameters:
        pvargDest - [out] The destination variant. If this is the same as pvarSrc, the variant will be converted in place.
        pvarSrc - [in] The variant to convert.
        wFlags - Combination of the following flags
        wFlags
        ValueMeaning
        VARIANT_NOVALUEPROPPrevents the function from attempting to coerce an object to a fundamental type by getting the Value property. Applications should set this flag only if necessary, because it makes their behavior inconsistent with other applications.
        VARIANT_ALPHABOOLConverts a VT_BOOL value to a string containing either "True" or "False".
        VARIANT_NOUSEROVERRIDEFor conversions to or from VT_BSTR, passes LOCALE_NOUSEROVERRIDE to the core coercion routines.
        VARIANT_LOCALBOOLFor conversions from VT_BOOL to VT_BSTR and back, uses the language specified by the locale in use on the local computer.
        vt - The type to convert to. If the return code is S_OK, the vt field of the vargDest is guaranteed to be equal to this value.
        Returns:
        This function can return one of these values:
        Return codeDescription
        S_OKSuccess.
        DISP_E_BADVARTYPEThe variant type is not a valid type of variant.
        DISP_E_OVERFLOWThe data pointed to by pvarSrc does not fit in the destination type.
        DISP_E_TYPEMISMATCHThe argument could not be coerced to the specified type.
        E_INVALIDARGOne of the arguments is not valid.
        E_OUTOFMEMORYInsufficient memory to complete the operation.

        Remarks

        The VariantChangeType function handles coercions between the fundamental types (including numeric-to-string and string-to-numeric coercions). The pvarSrc argument is changed during the conversion process. For example, if the source variant is of type VT_BOOL and the destination is of type VT_UINT, the pvarSrc argument is first converted to VT_I2 and then the conversion proceeds. A variant that has VT_BYREF set is coerced to a value by obtaining the referenced value. An object is coerced to a value by invoking the object's Value property (DISPID_VALUE).

        Typically, the implementor of IDispatch.Invoke determines which member is being accessed, and then calls VariantChangeType to get the value of one or more arguments. For example, if the IDispatch call specifies a SetTitle member that takes one string argument, the implementor would call VariantChangeType to attempt to coerce the argument to VT_BSTR. If VariantChangeType does not return an error, the argument could then be obtained directly from the bstrVal field of the VARIANT. If VariantChangeType returns DISP_E_TYPEMISMATCH, the implementor would set Invoke puArgErr parameter referenced value to 0 (indicating the argument in error) and return DISP_E_TYPEMISMATCH from Invoke.

        Arrays of one type cannot be converted to arrays of another type with this function.

        Note The type of a VARIANT should not be changed in the rgvarg array in place.
      • VariantChangeType

        WinNT.HRESULT VariantChangeType​(Variant.VARIANT.ByReference pvargDest,
                                        Variant.VARIANT.ByReference pvarSrc,
                                        short wFlags,
                                        WTypes.VARTYPE vt)
        Converts a variant from one type to another.
        Parameters:
        pvargDest - [out] The destination variant. If this is the same as pvarSrc, the variant will be converted in place.
        pvarSrc - [in] The variant to convert.
        wFlags - Combination of the following flags
        wFlags
        ValueMeaning
        VARIANT_NOVALUEPROPPrevents the function from attempting to coerce an object to a fundamental type by getting the Value property. Applications should set this flag only if necessary, because it makes their behavior inconsistent with other applications.
        VARIANT_ALPHABOOLConverts a VT_BOOL value to a string containing either "True" or "False".
        VARIANT_NOUSEROVERRIDEFor conversions to or from VT_BSTR, passes LOCALE_NOUSEROVERRIDE to the core coercion routines.
        VARIANT_LOCALBOOLFor conversions from VT_BOOL to VT_BSTR and back, uses the language specified by the locale in use on the local computer.
        vt - The type to convert to. If the return code is S_OK, the vt field of the vargDest is guaranteed to be equal to this value.
        Returns:
        This function can return one of these values:
        Return codeDescription
        S_OKSuccess.
        DISP_E_BADVARTYPEThe variant type is not a valid type of variant.
        DISP_E_OVERFLOWThe data pointed to by pvarSrc does not fit in the destination type.
        DISP_E_TYPEMISMATCHThe argument could not be coerced to the specified type.
        E_INVALIDARGOne of the arguments is not valid.
        E_OUTOFMEMORYInsufficient memory to complete the operation.

        Remarks

        The VariantChangeType function handles coercions between the fundamental types (including numeric-to-string and string-to-numeric coercions). The pvarSrc argument is changed during the conversion process. For example, if the source variant is of type VT_BOOL and the destination is of type VT_UINT, the pvarSrc argument is first converted to VT_I2 and then the conversion proceeds. A variant that has VT_BYREF set is coerced to a value by obtaining the referenced value. An object is coerced to a value by invoking the object's Value property (DISPID_VALUE).

        Typically, the implementor of IDispatch.Invoke determines which member is being accessed, and then calls VariantChangeType to get the value of one or more arguments. For example, if the IDispatch call specifies a SetTitle member that takes one string argument, the implementor would call VariantChangeType to attempt to coerce the argument to VT_BSTR. If VariantChangeType does not return an error, the argument could then be obtained directly from the bstrVal field of the VARIANT. If VariantChangeType returns DISP_E_TYPEMISMATCH, the implementor would set Invoke puArgErr parameter referenced value to 0 (indicating the argument in error) and return DISP_E_TYPEMISMATCH from Invoke.

        Arrays of one type cannot be converted to arrays of another type with this function.

        Note The type of a VARIANT should not be changed in the rgvarg array in place.
      • SafeArrayCreate

        OaIdl.SAFEARRAY.ByReference SafeArrayCreate​(WTypes.VARTYPE vt,
                                                    WinDef.UINT cDims,
                                                    OaIdl.SAFEARRAYBOUND[] rgsabound)
        Creates a new array descriptor, allocates and initializes the data for the array, and returns a pointer to the new array descriptor.
        Parameters:
        vt - [in] The base type of the array (the VARTYPE of each element of the array). The VARTYPE is restricted to a subset of the variant types. Neither the VT_ARRAY nor the VT_BYREF flag can be set. VT_EMPTY and VT_NULL are not valid base types for the array. All other types are legal. cDims
        cDims - the number of dims
        rgsabound - the rgsabound
        Returns:
        Return value A safe array descriptor, or null if the array could not be created.
      • SafeArrayPutElement

        WinNT.HRESULT SafeArrayPutElement​(OaIdl.SAFEARRAY psa,
                                          WinDef.LONG[] idx,
                                          Pointer pv)
        Stores the data element at the specified location in the array.
        Parameters:
        psa - [in] An array descriptor created by SafeArrayCreate.
        idx - the idx
        pv - [in] The data to assign to the array. The variant types VT_DISPATCH, VT_UNKNOWN, and VT_BSTR are pointers, and do not require another level of indirection.
        Returns:
        Return value This function can return one of these values.
        S_OK
        Success.
        DISP_E_BADINDEX
        The specified index is not valid.
        E_INVALIDARG
        One of the arguments is not valid.
        E_OUTOFMEMORY
        Memory could not be allocated for the element.
      • SafeArrayGetUBound

        WinNT.HRESULT SafeArrayGetUBound​(OaIdl.SAFEARRAY psa,
                                         WinDef.UINT nDim,
                                         WinDef.LONGByReference bound)
        Retrieve the upper bound for the specified dimension of the supplied array
        Parameters:
        psa - [in] An array descriptor created by SafeArrayCreate.
        nDim - [in] the dimension, one based
        bound - [out] upper bound for the supplied dimension
        Returns:
        Return value This function can return one of these values.
        S_OK
        Success.
        DISP_E_BADINDEX
        The specified index is not valid.
        E_INVALIDARG
        One of the arguments is not valid.
      • SafeArrayGetLBound

        WinNT.HRESULT SafeArrayGetLBound​(OaIdl.SAFEARRAY psa,
                                         WinDef.UINT nDim,
                                         WinDef.LONGByReference bound)
        Retrieve the lower bound for the specified dimension of the supplied array
        Parameters:
        psa - [in] An array descriptor created by SafeArrayCreate.
        nDim - [in] the dimension, one based
        bound - [out] lower bound for the supplied dimension
        Returns:
        Return value This function can return one of these values.
        S_OK
        Success.
        DISP_E_BADINDEX
        The specified index is not valid.
        E_INVALIDARG
        One of the arguments is not valid.
      • SafeArrayGetElement

        WinNT.HRESULT SafeArrayGetElement​(OaIdl.SAFEARRAY psa,
                                          WinDef.LONG[] rgIndices,
                                          Pointer pv)
        Retrieves a single element of the array.

        The array is automaticly locked via SafeArrayLock and SafeArrayUnlock.

        Parameters:
        psa - [in] An array descriptor created by SafeArrayCreate.
        rgIndices - [in] A vector of indexes for each dimension of the array. The right-most (least significant) dimension is rgIndices[0]. The left-most dimension is stored at rgIndices[psa->cDims - 1].
        pv - [out] The element of the array.
        Returns:
        Return value This function can return one of these values.
        S_OK
        Success.
        DISP_E_BADINDEX
        The specified index is not valid.
        E_INVALIDARG
        One of the arguments is not valid.
        E_OUTOFMEMORY
        Memory could not be allocated for the element.
      • SafeArrayPtrOfIndex

        WinNT.HRESULT SafeArrayPtrOfIndex​(OaIdl.SAFEARRAY psa,
                                          WinDef.LONG[] rgIndices,
                                          PointerByReference ppv)
        Retrieves the pointer to a single element of the array.

        The caller is responsible for locking.

        Parameters:
        psa - [in] An array descriptor created by SafeArrayCreate.
        rgIndices - [in] A vector of indexes for each dimension of the array. The right-most (least significant) dimension is rgIndices[0]. The left-most dimension is stored at rgIndices[psa->cDims - 1].
        ppv - [out] The element of the array.
        Returns:
        Return value This function can return one of these values.
        S_OK
        Success.
        DISP_E_BADINDEX
        The specified index is not valid.
        E_INVALIDARG
        One of the arguments is not valid.
      • SafeArrayLock

        WinNT.HRESULT SafeArrayLock​(OaIdl.SAFEARRAY psa)
        Increments the lock count of an array, and places a pointer to the array data in pvData of the array descriptor.
        Parameters:
        psa - [in] An array descriptor created by SafeArrayCreate.
        Returns:
        Return value This function can return one of these values.
        S_OK
        Success.
        E_INVALIDARG
        The argument psa is not valid.
        E_UNEXPECTED
        The array could not be locked.
      • SafeArrayUnlock

        WinNT.HRESULT SafeArrayUnlock​(OaIdl.SAFEARRAY psa)
        Decrements the lock count of an array so it can be freed or resized.
        Parameters:
        psa - [in] An array descriptor created by SafeArrayCreate.
        Returns:
        Return value This function can return one of these values.
        S_OK
        Success.
        E_INVALIDARG
        The argument psa is not valid.
        E_UNEXPECTED
        The array could not be locked.
      • SafeArrayDestroy

        WinNT.HRESULT SafeArrayDestroy​(OaIdl.SAFEARRAY psa)
        Destroys an existing array descriptor and all of the data in the array. If objects are stored in the array, Release is called on each object in the array.
        Parameters:
        psa - [in] An array descriptor created by SafeArrayCreate.
        Returns:
        Return value This function can return one of these values.
        S_OK
        Success.
        E_INVALIDARG
        The argument psa is not valid.
        DISP_E_ARRAYISLOCKED
        The array could not be locked.
      • SafeArrayRedim

        WinNT.HRESULT SafeArrayRedim​(OaIdl.SAFEARRAY psa,
                                     OaIdl.SAFEARRAYBOUND psaboundNew)
        Changes the right-most (least significant) bound of the specified safe array.
        Parameters:
        psa - [in, out] An array descriptor created by SafeArrayCreate.
        psaboundNew - [in] New bounds for the least significant dimension
        Returns:
        Return value This function can return one of these values.
        S_OK
        Success.
        E_INVALIDARG
        The argument psa is not valid.
        DISP_E_ARRAYISLOCKED
        The array could not be locked.
      • SafeArrayGetVartype

        WinNT.HRESULT SafeArrayGetVartype​(OaIdl.SAFEARRAY psa,
                                          WTypes.VARTYPEByReference pvt)
        Return VARTYPE of the SAFEARRAY
        Parameters:
        psa - [in] An array descriptor created by SafeArrayCreate.
        pvt - [in] Vartype of the SAFEARRAY
        Returns:
        Return value This function can return one of these values.
        S_OK
        Success.
        E_INVALIDARG
        The argument psa is not valid.
      • SafeArrayGetDim

        WinDef.UINT SafeArrayGetDim​(OaIdl.SAFEARRAY psa)
        Return number of dimensions of the SAFEARRAY
        Parameters:
        psa - [in] An array descriptor created by SafeArrayCreate.
        Returns:
        Return count of dimensions
      • SafeArrayAccessData

        WinNT.HRESULT SafeArrayAccessData​(OaIdl.SAFEARRAY psa,
                                          PointerByReference ppvData)
        Lock array and retrieve pointer to data
        Parameters:
        psa - [in] An array descriptor created by SafeArrayCreate.
        ppvData - [in] pointer to the data array
        Returns:
        Return value This function can return one of these values.
        S_OK
        Success.
        E_INVALIDARG
        The argument psa is not valid.
        E_UNEXPECTED
        The array could not be locked.
      • SafeArrayUnaccessData

        WinNT.HRESULT SafeArrayUnaccessData​(OaIdl.SAFEARRAY psa)
        Unlock array and invalidate the pointer retrieved via SafeArrayAccessData
        Parameters:
        psa - [in] An array descriptor created by SafeArrayCreate.
        Returns:
        Return value This function can return one of these values.
        S_OK
        Success.
        E_INVALIDARG
        The argument psa is not valid.
        E_UNEXPECTED
        The array could not be locked.
      • SafeArrayGetElemsize

        WinDef.UINT SafeArrayGetElemsize​(OaIdl.SAFEARRAY psa)
        Get size of one element in bytes
        Parameters:
        psa - [in] An array descriptor created by SafeArrayCreate.
        Returns:
        size in bytes
      • GetActiveObject

        WinNT.HRESULT GetActiveObject​(Guid.GUID rclsid,
                                      WinDef.PVOID pvReserved,
                                      PointerByReference ppunk)
        Retrieves a pointer to a running object that has been registered with OLE.
        Parameters:
        rclsid - [in] The class identifier (CLSID) of the active object from the OLE registration database.
        pvReserved - Reserved for future use. Must be null.
        ppunk - [out] The requested active object.
        Returns:
        Return value If this function succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.
      • LoadRegTypeLib

        WinNT.HRESULT LoadRegTypeLib​(Guid.GUID rguid,
                                     int wVerMajor,
                                     int wVerMinor,
                                     WinDef.LCID lcid,
                                     PointerByReference pptlib)
        Uses registry information to load a type library.
        Parameters:
        rguid - The GUID of the library.
        wVerMajor - The major version of the library.
        wVerMinor - The minor version of the library.
        lcid - The national language code of the library.
        pptlib - The loaded type library. This function can return one of these values: S_OK Success. E_INVALIDARG One or more of the arguments is not valid. E_OUTOFMEMORY Insufficient memory to complete the operation. TYPE_E_IOERROR The function could not write to the file. TYPE_E_INVALIDSTATE The type library could not be opened. TYPE_E_INVDATAREAD The function could not read from the file. TYPE_E_UNSUPFORMAT The type library has an older format. TYPE_E_UNKNOWNLCID The LCID could not be found in the OLE-supported DLLs. TYPE_E_CANTLOADLIBRARY The type library or DLL could not be loaded.
        Returns:
        status
      • LoadTypeLib

        WinNT.HRESULT LoadTypeLib​(String szFile,
                                  PointerByReference pptlib)
        Loads and registers a type library.
        Parameters:
        szFile - The name of the file from which the method should attempt to load a type library.
        pptlib - The loaded type library. Return value This function can return one of these values. S_OK Success. E_INVALIDARG One or more of the arguments is not valid. E_OUTOFMEMORY Insufficient memory to complete the operation. TYPE_E_IOERROR The function could not write to the file. TYPE_E_INVALIDSTATE The type library could not be opened. TYPE_E_INVDATAREAD The function could not read from the file. TYPE_E_UNSUPFORMAT The type library has an older format. TYPE_E_UNKNOWNLCID The LCID could not be found in the OLE-supported DLLs. TYPE_E_CANTLOADLIBRARY The type library or DLL could not be loaded.
        Returns:
        status
      • SystemTimeToVariantTime

        int SystemTimeToVariantTime​(WinBase.SYSTEMTIME lpSystemTime,
                                    DoubleByReference pvtime)
        Converts a system time to a variant representation.
        Parameters:
        lpSystemTime - [in] The system time.
        pvtime - [out] The variant time.
        Returns:
        The function returns TRUE on success and FALSE otherwise.