Clearing callouts when another is clicked

I am fairly new to C#/.NET and have been working through building an app. I know .NET7 recently released and brought map functionality to Maui, but have already implemented code using MAPSUI. There doesn’t seem to be great documentation surrounding the usage of this, however.

Looking through their getting started page and their examples on Github (specifically: SingleCalloutSample) I was able to get my list of places to show up on the map and when clicked display certain features.This has led to me only being able to toggle whether the callout is displayed or not. What I am hoping to figure out is how to disable all other callouts once another location is selected, so that only a single callout is displayed at a time.

I am aware the following code is the logic dictating the callout displays, but not sure how to adjust it to “wipe” existing callouts on click. Any help would be greatly appreciated:

private static void MapOnInfo(object? sender, MapInfoEventArgs e)
{
var calloutStyle = e.MapInfo?.Feature?.Styles.Where(s => s is CalloutStyle).Cast().FirstOrDefault();
if (calloutStyle != null)
{
calloutStyle.Enabled = !calloutStyle.Enabled;
e.MapInfo?.Layer?.DataHasChanged(); // To trigger a refresh of graphics.
}
}

[charlenni]

Ok, if you don’t want to use Pins, then you have to do it by hand.

The function CreatePointLayer() creates a MemoryLayerthat holds one or more Features. That are your pins. Each of this Feature has none (Feature isn’t drawn), one or more Styles. This Style tells Mapsui, how the Feature should be drawn. One of this Styles is the CalloutStyle. It says Mapsui, that at this place a callout should be drawn, but only, if CalloutStyle.Enabled=true.

To hide all callouts on your layer, you have to set Enabled=false for all Feature that have a CalloutStyle.

foreach(var feature in e.MapInfo?.Layer?.Features)
  foreach(var style in feature.Styles)
    if (style is CalloutStyle)
      ((CalloutStyle)style).Enabled = false;

That’s it.

Or you save the last Feature with a callout 😉

[RParkerE]

I found that e.MapInfo?.Layer extends from ILayer which has no definition for Features: CS1061 'ILayer' does not contain a definition for 'Features' and no accessible extension method 'Features' accepting a first argument of type 'ILayer' could be found (are you missing a using directive or an assembly reference?)

I did get this working by creating a List<CalloutStyle> calloutlist to keep track of clicked callouts and updated the code section as shown below:

private static void MapOnInfo(object? sender, MapInfoEventArgs e)
        {
            var calloutStyle = e.MapInfo?.Feature?.Styles.Where(s => s is CalloutStyle).Cast<CalloutStyle>().FirstOrDefault();
            if (calloutStyle != null)
            {
                calloutlist.Add(calloutStyle);
                foreach (var callout in calloutlist)
                {
                    callout.Enabled = false;
                }
                calloutStyle.Enabled = !calloutStyle.Enabled;
                e.MapInfo?.Layer?.DataHasChanged(); // To trigger a refresh of graphics.
            }
            if (calloutlist.Count > 1)
                calloutlist.RemoveRange(0, calloutlist.Count - 1);
        }