在 MS Excel 启动时使 IRibbonUI 无效

Question

I have created an Excel AddIn using C# VSTO. There are few ribbon buttons which are to be made available for the the selected users.

        private Office.IRibbonUI ribbon;
        private bool SuperUserEnabled= false;

        public Ribbon()
        {
        }
        public string GetCustomUI(string ribbonID)
        {
            return GetResourceText("MyUtilities.Ribbon.xml");
        }


        public void Ribbon_Load(Office.IRibbonUI ribbonUI)
        {          
            this.ribbon = ribbonUI;
        }


        public void RibbonActions(Office.IRibbonControl control)
        {          
            switch (control.Id)
            {
                case "Button1":
                    // some code
                    break;
                case "Button2":
                    //Some code
                     break;
             }
         }

The GetEnabled callback in xml file uses the below code to verify the user status.

        public bool CheckUserPrevilage(ref Office.IRibbonControl control)
    {
        //The idea is to validate only the first button. The rest are validated by virtue of the first button.
        if (control.Id == "Button1")
        {
            UserValidation UserStatus = new UserValidation();
            string UserPrevilage= UserStatus.GetUserPrevilage();

            if (UserPrevilage== "Super User")
            {
                SuperUserEnabled= true;
            }
        }
        return SuperUserEnabled; //SuperUserEnabled is a global variable
    }

Some users are given the permission as a super user after few months or the permission is taken back. The code need to check for the user privileges and invalidates the ribbon and enable or disable the ribbon.

When the user privilege is upgraded/downgraded, I am able to invalidate the ribbon with a button.

The problem I am facing now. It works in the debug/Release mode but not when the addIn is installed with the Click-once setup file.

In this case whatever is the installation status of the addin will remain forever. After the invalidation the buttons are enabled or disabled only for that session of the excel. If the excel is restarted, the buttons are taken from the original catch.

Is there a way to invalidate the ribbon at the start event of the excel.

Answer 1

Is there a way to invalidate the ribbon at the start event of the excel.

You need to use the IRibbonUI.Invalidate or IRibbonUI.InvalidateControl methods for that. For each of the callbacks the add-in implements, the responses are cached. For example, if an add-in writer implements the getImage callback procedure for a button, the function is called once, the image loads, and then if the image needs to be updated, the cached image is used instead of recalling the procedure. This process remains in-place until the add-in signals that the cached values are invalid by using the Invalidate method, at which time, the callback procedure is again called and the return response is cached. The add-in can then force an immediate update of the UI by calling the Refresh method.

Read more about the Fluent UI (aka Ribbon UI) in the following series of articles:

• Customizing the 2007 Office Fluent Ribbon for Developers (Part 1 of 3)
• Customizing the 2007 Office Fluent Ribbon for Developers (Part 2 of 3)
• Customizing the 2007 Office Fluent Ribbon for Developers (Part 3 of 3)