ATL创建的ActiveX实现JS回调

最近公司的产品需要使用ActiveX文件上传。讨论了基本所有的技术，最后还是决定C++搞个ActiveX。。。但上传的回调费了半天劲，才搞定。代码如下

STDMETHODIMP CFileSelector::TestJSInvoke(VARIANT scriptCallback)
{
	AFX_MANAGE_STATE(AfxGetStaticModuleState());

	CComPtr<IDispatch> spCallback;

	if(scriptCallback.vt == VT_DISPATCH)
		spCallback = scriptCallback.pdispVal;

	CComVariant avarParams[1];
	CFileDialog dlgFile(TRUE,NULL,NULL,OFN_ALLOWMULTISELECT | OFN_FILEMUSTEXIST,L"所有文件(*.*)|*.*||",NULL,NULL,FALSE);

	if(dlgFile.DoModal() == IDOK)
	{
		avarParams[0] = dlgFile.GetPathName();
	}

	DISPPARAMS params = { avarParams, NULL,1,0 };

	if(spCallback)
		spCallback->Invoke(0,
			IID_NULL,
			LOCALE_USER_DEFAULT,
			DISPATCH_METHOD,
			&params,NULL,NULL,NULL);

	return S_OK;
}

JS调用方法：

<script type="text/javascript">
        function OnClick() {
            var activeX = document.getElementById("ActiveX");
            activeX.FileExtFilter = "所有文件(*.*)|*.*||";
            activeX.TestJSInvoke(function (e) {
                alert(e);
            });
            return false;
        }
    </script>