DOCUMENT:Q191872 11-JAN-2001 [vbwin] TITLE :PRB: Enum HelpStrings Not Displayed in Properties Window PRODUCT :Microsoft Visual Basic for Windows PROD/VER: OPER/SYS: KEYWORDS:kbGrpDSVB ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual Basic Learning Edition for Windows, versions 5.0, 6.0 - Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0 - Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0 - Microsoft Visual Basic Standard Edition for Windows, version 4.0 - Microsoft Visual Basic Professional Edition for Windows, version 4.0 - Microsoft Visual Basic Enterprise Edition for Windows, version 4.0 ------------------------------------------------------------------------------- SYMPTOMS ======== HelpStrings of Enum types in an ActiveX control developed in Visual C++ are not displayed in the Properties Window of Visual Basic 5.0 and 6.0. This behavior differs from previous versions of Visual Basic. CAUSE ===== When an ActiveX control is developed in Visual C++, Enum types can be declared in the control's ODL file, and subsequently used by the control's properties. HelpStrings can also be associated with the members of the Enum to help define the property. Here is a segment of an ODL file for an ActiveX control built in MFC: typedef enum tagLineStyleConstants { [helpstring("Solid")] lsSolid = 0, [helpstring("Dash")] lsDash = 1, [helpstring("Dot")] lsDot = 2, [helpstring("Dash-Dot")] lsDashDot = 3, [helpstring("Dash-Dot-Dot")] lsDashDotDot = 4, } LineStyleConstants; .... properties: // NOTE - ClassWizard will maintain property information here. // Use extreme caution when editing this section. //{{AFX_ODL_PROP(CEnumCtrl) [id(1)] LineStyleConstants LineStyle; //}}AFX_ODL_PROP When the ActiveX control has been sited on a form in Visual Basic 4.0, you can see that the value of the LineStyle property, when viewed from the Properties Window, is composed of all the HelpStrings of the Enum type. It looks similar to the following: 0 - Solid 1 - Dash 2 - Dot 3 - Dash-Dot 4 - Dash-Dot-Dot However, when this ActiveX control is sited on a form in Visual Basic 5.0 or 6.0, you can see that the value of the LineStyle property is composed of all the members of the Enum type rather than the HelpStrings. It looks similar to the following: 0 - lsSolid 1 - lsDash 2 - lsDot 3 - lsDashDot 4 - lsDashDotDot Visual Basic 5.0 or 6.0 reserve the HelpStrings for descriptive explanations of each Enum member when viewed in the Object Browser. RESOLUTION ========== There are several solutions for this issue: 1. Make the name of each element in your Enum types as meaningful as possible so users of your control could figure out its meaning from the name. 2. Implement the members of the IPerPropertyBrowsing interface, which allow clients to query your control for descriptive strings for properties viewed from a Property Page and Visual Basic's Properties Window. 3. Create property pages for your properties. The Enum HelpStrings will be used in property pages. For additional information regarding solution 2 or 3 above, please refer to the following article in the Microsoft Knowledge Base: Q141488 SAMPLE: Using Enumerated Properties in an OLE Control STATUS ====== This behavior is by design. MORE INFORMATION ================ Steps to Build an ActiveX Control in MFC ---------------------------------------- 1. Start Visual C++ 5.0 and create a new control project using the MFC ActiveX ControlWizard. Name the project EnumTest, and click OK. When the wizard comes up, press Finish to accept the default settings. 2. From the ClassView tab, right-click on _DEnumTest and select "Add Property" from the context menu. Add the name LineStyle to the dialog's External Name text box, and choose long as the data type. Accept the default variable name and function by click OK. 3. From the Files tab, open the EnumTest.odl file and add the following inside your type library, just under the importlib(STDTYPE_TLB) statement: typedef enum tagLineStyleConstants { [helpstring("Solid")] lsSolid = 0, [helpstring("Dash")] lsDash = 1, [helpstring("Dot")] lsDot = 2, [helpstring("Dash-Dot")] lsDashDot = 3, [helpstring("Dash-Dot-Dot")] lsDashDotDot = 4, } LineStyleConstants; 4. Continue down and change the data type for the newly-added property from a long to the enum type LineStyleConstants: // NOTE - ClassWizard will maintain property information here. // Use extreme caution when editing this section. //{{AFX_ODL_PROP(CEnumTestCtrl) [id(1)] LineStyleConstants LineStyle; //}}AFX_ODL_PROP 5. Compile your control. MFC will register the control for you. Steps to Test the Control in Visual Basic ----------------------------------------- 1. Open Visual Basic and create a new Standard EXE project. Form1 is created by default. 2. From the Project|Components menu, add the control EnumTest.ocx to the Visual Basic Toolbox. 3. Add an instance of the EnumTest.ocx control to Form1. 4. From the Properties window, look for the LineStyle property. You can change the value of the LineStyle property from the dropdown combobox. On Visual Basic 4.0, these items will be composed of the Enum type HelpStrings. On Visual Basic 5.0 and Visual Basic 6.0, the member names themselves will appear. Additional query words: kbDSupport kbDSD kbVBp kbVBp400 kbVBp500 kbVBp600 kbCtrlCreate kbVC500 kbWizard ====================================================================== Keywords : kbGrpDSVB Technology : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500 kbVBA600 kbVB500 kbVB600 kbVB400Search kbVB400 Issue type : kbprb ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. 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