Why does my custom pin shows label only for the last pin in Xamarin Forms Maps?

Question

I implemented the custom map and custom pin as the example from docs.microsoft, but when I tap on a pin if its not the last one created pin then it cannot find the pin:

The error appears here in the Android Renderer

var customPin = GetCustomPin(marker);
                if (customPin == null)
                {
                    throw new Exception("Custom pin not found");
                }

customPin can't get the values

This is how I place the pins:

CustomPin pin = new CustomPin();
            pin.Type = PinType.Place;
            pin.Label = "Bus # 1";
            pin.Address = "394 Pacific Ave, San Francisco CA";
            pin.Name = "Xamarin";
            pin.Url = "url test";
            pin.Position = (new Position(9.934224393214128, -84.08272226354063));
            map.CustomPins = new List<CustomPin> { pin };
            map.Pins.Add(pin);
            map.MoveToRegion(MapSpan.FromCenterAndRadius(new Position(9.934224393214128, -84.08272226354063), Distance.FromMiles(1.0)));



            CustomPin pin2 = new CustomPin();
            pin2.Type = PinType.Place;
            pin2.Label = "Bus # 2";
            pin2.Address = "394 Pacific Ave, San Francisco CA";
            pin2.Name = "Xamarin";
            pin2.Url = "url test";
            pin2.Position = (new Position(9.932673627402988, -84.07538128629682));
            map.CustomPins = new List<CustomPin> { pin2 };
            map.Pins.Add(pin2);
            map.MoveToRegion(MapSpan.FromCenterAndRadius(new Position(9.932673627402988, -84.07538128629682), Distance.FromMiles(1.0)));

I believe the issue is here

map.CustomPins = new List<CustomPin> { pin2 };

because of the "new" but how can I make this different to add as many pin as I want?

This is what I've tried

List<CustomPin> CustomPinsList = new List<CustomPin>();
CustomPinsList.Add(pin2);
map.CustomPins.Add(CustomPinsList[1]);

and this

map.CustomPins.Add(pin);

yeah, as I understand both are refering to the CustomPin class — Techy Hernández, May 24 '21 at 21:02
where are you initializing `customPins`? If you don't then it will be null and you will get a null ref exception. I suspect that you only want `CustomPins`, but without seeing more code I can't say for sure. — Jason, May 24 '21 at 21:09
customPins is initialized in the Android Custom Renderer "List customPins;" code is the same as in here https://github.com/xamarin/xamarin-forms-samples/blob/main/CustomRenderers/Map/Droid/CustomMapRenderer.cs — Techy Hernández, May 24 '21 at 21:14
well, then you need to start by figuring which line is causing the exception, and then which element of that line is null — Jason, May 24 '21 at 21:17
customPins takes values in the renderer from CustomPins, but CustomPins is already null by that point — Techy Hernández, May 24 '21 at 21:18
if you know that "CustomPins is already null" then why haven't you fixed it? — Jason, May 24 '21 at 21:22
because I don't know in which part the values get lost, when adding the pin the map.CustomPins does have a value — Techy Hernández, May 24 '21 at 21:29
welcome to the world of debugging. You just have to work through it — Jason, May 24 '21 at 21:31
every time you create a pin you are creating a new instance of `CustomPins` instead of adding to the existing instance — Jason, May 24 '21 at 22:31
have you instantiated `CustomPins` before you try to use it? Any object in C# needs to be instantiated before it can be accessed — Jason, May 24 '21 at 23:15
`map.CustomPins = new List();`. You only need to do this **once**, then you can add pins to the list — Jason, May 24 '21 at 23:27

Why does my custom pin shows label only for the last pin in Xamarin Forms Maps?

0 Answers0