This sample demonstrates how you can hide or show sublayers of a map image layer. The list on the side displays the list of sublayers present in the map. Each sublayer in the list has a checkbox, which can be used to toggle visibility of that particular sublayer.
How it works
The mapImageSublayers property on AGSArcGISMapImageLayer is used to get the list of AGSArcGISMapImageSublayer. Each of these sublayer has a property called isVisible, which is used to toggle visibility.