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I display a balloon callout after casting a axMapControl.Map to a IActiveView and doing this:

pGraphicsContainer = activeView as IGraphicsContainer;
pGraphicsContainer.AddElement(pElement, zOrder); 
pElement.Activate(activeView.ScreenDisplay); 

The problem is the balloon callout displays below the place labels layer. The text "Minneapolis" is visible on top of my balloon callout. I have tested zOrder with values from -10 to 10000 and the place labels still render on top of the balloon callout.

1 Answer 1

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From the IGraphicsContainer.AddElement documentation:

The parameter zorder is currently not utilized by all of the IGraphicsContainer implementations and is typically set to 0 when calling this method.

You can alter the element z-order using methods like IGraphicsContainer.BringToFront, SendToBack, BringForward and SendBackward. I suppose GetElementOrder and SetElementOrder also serve for this purpose, allowing you to set the z-order at once, but I've never tested.

Anyway, this affects only the z-order of graphic elements, not layer labeling, which is a separate process. Depending on the layer label weight settings, labels draw next to graphic elements (using a placement conflict resolution algorithm) or above them. I remember I was able to tweak this behaviour by creating a separate graphics layer under the map's BasicGraphicsLayer, adding graphic elements to it, and setting this graphic layer's IBarrierProperties.Weight accordingly.

Hope this helps.

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    Some example code would be exemplary. I can't find the SetElementOrder call and using BringForward hangs the application for some reason. So I would really appreciate an example from anyone. Commented May 17, 2017 at 0:19

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