Need help on call COM method from VBScript.

Hi sm_ch,

Since you are using vb script, everything needs to be a VARIANT.

Return HRESULTs.

To return a value to a client, you need a [out, retval] parameter.

Use BSTRs instead of LPCTSTR.

Note that VBScript requires VARIANTs - if you have a smart Automation aware language such as VB or Visual Java, you could actually pass BSTR*'s as parameters/return values.

Something similar to below should work...

See http://msdn.microsoft.com/library/de...ion_topics.asp and http://msdn.microsoft.com/library/de...chap7_5alv.asp

See also http://msdn.microsoft.com/library/de...chap6_7zdz.asp for the VARIANT structure.

Jeff

Code:

[id(1), helpstring("method Test")] HRESULT Test( [in] VARIANT* param, [out, retval] VARIANT* retval );

And

Code:

STDMETHODIMP CTest::Test(VARIANT* param, VARIANT* retval) { if( NULL == param || param->vt != VT_BSTR ) { return E_INVALIDARG; } if( NULL == retval || retval->vt != VT_BSTR ) { return E_INVALIDARG; } HRESULT hr = SysFreeString( *retval ); if( FAILED( hr) ) { return hr; } USES_CONVERSION; LPCTSTR szParam = OLE2T(param); // tinker with szParam *retval = SysAllocString( szParam ); if( NULL == *retval ) { return E_MEMORY; } return S_OK; }