The issues discussed here apply to ActiveX controls used with Office 97 applications. Some of these issues apply only to specific applications within the Office 97 and are called out as appropriate.
1. The ActiveX control container implementations in Word, Excel and PowerPoint 97 use the IDataObject interface and not IViewObject to draw controls. ActiveX controls (from Microsoft or other vendors) that do not support IDataObject but instead require IViewObject support in their containers will not work in Word, Excel or PowerPoint 97 documents. Access 97 does not have this limitation and can host controls that do not support IDataObject. Note that Microsoft Forms (used to create custom user dialogs in Microsoft Word, Microsoft Excel, Microsoft Outlook, and Microsoft PowerPoint 97) do not have this restriction either.
You need to contact the control vendor to determine whether an ActiveX control requires the IViewObject interface to be supported in its container.
2. ActiveX controls may behave unpredictably when seen in multiple views of the same document. For an ActiveX control to display and function properly in multiple views of the same document (windows or panes), the container application should support the IViewObject interface. Since Word, Excel and PowerPoint 97 do not support this interface (as discussed in 1 above), the behavior of an ActiveX control that is viewed in two different windows (e.g., using Window.New Window, or by using the splitter pane) may be unpredictable.
3.There is a class of ActiveX controls called simple frame controls that implement and interface called ISimpleFrame and will only work inside containers that support the ISimpleFrameSite interface. Access, Word, Excel and PowerPoint 97 do not support ISimpleFrameSite and will not be able to host such controls. This is also true for Microsoft Forms.
4. In-place limitations
a) When Excel 97 is in-place active inside a container, ActiveX controls in Excel’s worksheets cannot be activated. When the user clicks on an ActiveX control while Excel 97 is in-place active, the following alert will appear – “This control can only be used while the sheet is in a Microsoft Excel window. Open into a Microsoft Excel Window?”. This alert will have Yes and No buttons; choosing No will result in no action, choosing Yes will open the embedding in its native Excel application window where the control will be fully functional .
Note that ActiveX controls in the in-place active Excel worksheet will be displayed correctly and can even be selected in Design Mode – these controls are simply restricted from being in-place active. If it is important that controls be fully functional when an Excel sheet is in-place active, developers have the option of using built-in Excel controls available on the Forms toolbar .
b) Whenever an ActiveX control in an in-place active Word document gets UI activation (e.g., when the user clicks on a button control on a Word document embedded in Internet Explorer), Word’s toolbars and menus will un-merge themselves from those belonging to the container. When the focus returns to the Word document (e.g., the same user clicks on text anywhere in the same Word document) the Word toolbars and menus will re-merge with the container ones. This behavior may result in UI-flashing when dealing with a Word document with ActiveX controls being activated as a Binder section or as an ActiveX document inside of Internet Explorer.
5. Excel Charts cannot contain ActiveX controls
ActiveX controls cannot be inserted into Excel 97 charts. Controls may be placed on top of chart objects that are embedded in a worksheet, but such controls will not be active when the chart is activated.
6. “Component Categories” are not supported by Word, Excel or PowerPoint 97.
Word, Excel and PowerPoint 97 do not support ActiveX control categories. The implication is that controls that show up in the UI to insert non-Office controls may not necessarily work in these Office applications. There is no UI-filtering based on component categories, so it is possible, for instance, for an ISimpleFrame control to show up in the “More Controls” list for Word even though it would not work there.
Access 97 supports component categories, controls that Access does not support will not show up in their control list. This functionality requires that the control vendor building controls that support categories.
7. No automatic download of ActiveX controls embedded in Office 97 documents when browsing using Internet Explorer
While browsing an intranet web with a mixture of HTML and Office 97 documents using Internet Explorer 3.0 (or higher), ActiveX controls embedded in Office 97 documents do not get automatically downloaded to the client machine. On the other hand, IE ensures that this happens automatically in the case of HTML pages that have ActiveX controls in them. The one case where this will work is when the client machine has Office 97 installed and the document in question makes exclusive use of the ActiveX controls that ship in the Office 97 box.
8. Miscellaneous limitations
The following additional ActiveX control features are not supported in Access, Word, Excel or PowerPoint 97.