Can I intercept marker deselect when I tap another

问题:

I know that I can use didTapAtCoordinate that will deselect the marker when I tap else where on the map. But If there are multiple marker and I tap another one (Ex. MarkerA -> MarkerB), Is there any call back when the previous marker DidDeselect?. I look around in GMSMapView the but can't find any thing I can use.

I want to change the marker color or image when it being selected and change it back when another marker select or the marker deselect.

Thank you.

回答1:

The doco for selectedMarker says:

The marker that is selected. Setting this property selects a particular marker, showing an info window on it. If this property is non-nil, setting it to nil deselects the marker, hiding the info window. This property is observable using KVO.

So, you could use Key Value Observing to be notified of changes to selectedMarker. If you use NSKeyValueObservingOptionOld when setting up KVO (described in more detail here), you will be notified of the old value, ie the marker which was deselected.