Tooltip on GoImage

I’m having a problem with the GoImage.

My diagram contains custom GoTextNodes, each of them contains little images. What I would like to do is to use tooltip on the little images, unfortunately I was unable to make that happen.
So, I used an other solution : I transformed my GoImages to GoTextNodes and the background of the Gotextnode is an other GoImage containing the good path. So it works perfectly unless I can't change the size of the component, whatever the size of the physical icon or the size I tell for the GotextNode or the image, it doesn't resize at all.
So, the easiest solution should be to have tooltips directly on my original GoImage (I tried to overrides method GetTooltip but i didn't succeed), at that time I was able to change the size. If it's not possible, can you explain me and give me a solution to resize the GoTextNode containing a GoImage.

Well, the easiest solution might be to just set the GoNode.ToolTipText property. That will cause any part of the node to get that string as the tooltip.

If you just want the GoImage to have a tooltip, and have the rest of the node not have any tooltip or to have a different tooltip, then you'll need to override GoObject.GetToolTip on a class that inherits from GoImage.
I can't explain why overriding that method wouldn't work for you. That's how it is implemented for the GoNode class, which makes use of that GoNode.ToolTipText property. Maybe you aren't actually using your subclass of GoImage in your node.
I overrided GoImage and it worked perfectly. I don't know what I did the first. But I think it's not obvious to understand that the function "GetToolTip" permits to display a tooltip on the screen (that's just my opinion )
Thanks, it's exactly what I wanted to do.