Xamarin.Forms如何在MapView上创建可拖动标记（Marker）？

Hi there! Since you already have Android and Swift development experience, you’ll catch on to this fast. Here’s your starting direction for implementing draggable markers (since the out-of-the-box Xamarin.Forms.Map only supports basic Pins):

• Use Custom Renderers: This is the go-to way to tap into native platform features in Xamarin.Forms. You’ll build platform-specific renderers for your Map control to hook into the native Google Maps (Android) and MapKit (iOS) APIs you already know.
  • For Android:
    • Create a custom renderer that inherits from MapRenderer
    • Access the native GoogleMap instance in the renderer
    • When creating native Markers from your Forms Pins, set Draggable = true
    • Listen to native drag events (MarkerDragStart, MarkerDrag, MarkerDragEnd) and pass these events back to a custom Xamarin.Forms Map subclass (you’ll need to define this subclass with drag event handlers)
  • For iOS:
    • Build a custom renderer inheriting from MapRenderer
    • Get the native MKMapView
    • For the MKAnnotationView corresponding to your Forms Pin, set Draggable = true
    • Implement the MKMapViewDelegate methods like DidDragAnnotationView to handle drag events and relay them to your Forms-level Map control
• Optional: Custom DraggablePin Class: Define a subclass of Pin (e.g., DraggablePin) to flag which pins should be draggable. This makes it easier to handle only specific pins in your renderers instead of all pins.

内容的提问来源于stack exchange，提问作者TJBlack31