How to add a button to a pre-existing tab on ribbon (C#)?

Question

I\'ve successfully created a new tab and put it next to the pre-existing ones. Then I realized that I\'ll only have one button on it, so it makes more sense (for now) to put it

Answer 1

If you just want a button to appear in an existing ribbon, in Visual Studio, here https://msdn.microsoft.com/en-us/library/bb608628.aspx#Anchor_2

in your case change the OfficeId to TabMail

Answer 2

For people frustrated that none of the other answers seem to be working, go to the properties for the Ribbon itself and set the RibbonType to Microsoft.Outlook.Explorer (or whichever context[s] you want to see the control in). It's a crucial step that's easy to overlook.

Then follow the other instructions to set OfficeId to TabMail.

Additionally, Office 2016 Fluent Control Identifiers can be found here: https://www.microsoft.com/en-us/download/confirmation.aspx?id=50745

Answer 3

The attribute idMso is correct, but the id for the tab you want is TabMail. You can find a packed set of Excel-files containing lists of Office 2010 control IDs on MSDN. Then, as mentioned in a comment to the question, your sample XML may be missing the customUI and ribbon-tags. (Disclaimer: I haven't customized the ribbon in Outlook, only Word, Excel and PowerPoint, but I would guess they work the same?)

Try something like the this:

<?xml version="1.0" encoding="UTF-8"?>
<customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui">
    <ribbon>
        <tabs>
            <tab idMso="TabMail">
                <group id="group1" label="Hazaa!">
                    <box id="box1" />
                </group>
            </tab>
        </tabs>
    </ribbon>
</customUI>

Answer 4

Edited. Sorry, gave a dnn link. You want office and you want c#.

Here's a StackOverflow answer in VBA... How to get Ribbon custom Tabs IDs?

AccessibleChildren _
            Lib "oleacc.dll" _
                (ByVal paccContainer As Object, _
                 ByVal iChildStart As Long, _
                 ByVal cChildren As Long, _
                       rgvarChildren As Variant, _
                       pcObtained As Long) _
            As Long

Which in C# translates to

[Lib "oleacc.dll"]
Long AccessibleChildren(object paccContainer, 
                        long iChildStart, 
                        long cChildren, 
                        object rgvarChildren, 
                        long pcObtained)...

I never tried it, so not sure it works.

From all other documentation, it seems you simply get the ribbon object, and in it iterate (with foreach) through all the children