Dynamically Change Button Image in Excel 2010 - excel

Question

I'm using XML to create a custom Excel Ribbon in which I have a button that contains an image. I would like to be able to change this image when the button is pressed (like a toggle) to show what state it's in. I have the following XML to describe the button:
<button id="MyButton"
label="MyLabel"
screentip="Some useful info."
onAction="MyAction"
getImage="GetImage"
size="large"/>
Where the MyAction method is defined as:
public void MyAction(Office.IRibbonControl control)
{
// Change button image here...
}
Is there some way I can change the button's image in the MyAction() method?
Cheers

Answer 1

EDIT: sorry, I just realised this was on the C# forum and I wrote the functions in VB. Do you need me to have the code translated into C#? Note that the callback behavior should be the same.
I find the easiest way to do update a control is to Invalidate the control or the whole ribbon and have the parameters update through the control's callbacks like getImage, getVisible, getLabel, etc
What I write here will work for any of a controls' parameters (label, enabled, visible, ...)
So if you define your button in the XML this way:
<button id="MyButton"
label="MyLabel"
onAction="OnAction"
getImage="GetImage"/>
You can then use the OnAction callback to update the button's paramater this way (assuming that you have a boolean variable called condition):
Public Sub OnAction(ByVal control As Office.IRibbonControl)
// Do your button stuff here
condition = Not condition
gui.InvalidateControl(control.Id)
End Sub
Then the callbacks of the button will get called, for getImage you can use:
Public Function GetImage(ByVal control As Office.IRibbonControl) As String
If condition Then
Return "MacroPlay"
Else
Return "DeclineInvitation"
End If
End Function
Note that for all this to work you need to store the Ribbon into the gui variable. For this you need to use in the XML:
<customUI xmlns="http://schemas.microsoft.com/office/2006/01/customui" onLoad="OnRibbonLoad"> ...
and in the code:
Public Sub OnRibbonLoad(ByVal ribbon As Office.IRibbonUI)
gui = ribbon
End Sub

Answer 2

It looks as though you are correct. The only way I have found to edit the appearance of custom ribbon elements is to use 'Ribbon (Visual Designer)' and not XML.
For example, if I want to change an image on a toggle button called toggleButton1 I can do the following:
public void toggleButton1_Click(object sender, RibbonControlEventArgs e)
{
toggleButton1.Image = GetImage(toggleButton1.Checked);
}
where GetImage is defined as:
public Bitmap GetImage(bool pressed)
{
return new Bitmap(pressed ? Properties.Resources.img_1 : Properties.Resources.img_2);
}
Cheers

Answer 3

<button id="MyButton" label="MyLabel" onAction="OnAction" getImage="GetImage"/>
The solution above worked for me. Just make sure that you don't use loadImage event on your customUI xml node. Looks like if you use both loadImage and GetImage then addin fails to load.