I want map zoomed such that from the center on either side to 50 kilometer

[Girishchandra_Yendargaye]

I want map zoomed such that from the center on either side  to 50 kilometer

[LucasDanzinger]

Buffer the input geometry by 50 km using the GeometryEngine::buffer - https://developers.arcgis.com/qt/latest/cpp/api-reference/esri-arcgisruntime-geometryengine.html#buf... 

Then call setViewpoint with the returned Geometry

[Girishchandra_Yendargaye]

But how to find center of map which added as operational layer.