How to group the markers based on zoom level in the .NET MAUI Maps (SfMaps)?

In the Syncfusion .NET MAUI Maps control, group the markers based on zoom level, that is to display individual markers in the corresponding location while zooming into a high zoom level, and to combine the individual markers to form a single group and displaying as a single marker while zooming out using the ZoomLevelChanging event of the MapTileLayer in the SfMaps through the following steps.

Step 1: Add the SfMaps control to your layout, initialize the MapTileLayer, and set the OSM tiles provider in the UrlTemplate property of the MapTileLayer as shown in the following code sample.

XAML:

<map:SfMaps>
   <map:SfMaps.Layer>
   	<map:MapTileLayer x:Name="layer"
   			  UrlTemplate="https://tile.openstreetmap.org/{z}/{x}/{y}.png">
   	</map:MapTileLayer>
   </map:SfMaps.Layer>
</map:SfMap>

Step 2: To add show a custom marker, add the image to be displayed as a marker to the project’s root folder or subfolder, right-click the added image, select properties, then select the MauiImage option under Build Action.

Step 3: Add the image content to the layout’s resources in the form of DataTemplate and set that template to the MarkerTemplate property of the MapTileLayer as shown in the following code sample.

XAML:

<ContentPage.Resources>
   <ResourceDictionary>
       <DataTemplate x:Key="markerTemplate">
           <StackLayout HorizontalOptions="StartAndExpand"
                        VerticalOptions="Center">
               <Image Source="pin.png"
                      HeightRequest="30" 
                      WidthRequest="30" />
           </StackLayout>
       </DataTemplate>
   </ResourceDictionary>
</ContentPage.Resources>
<ContentPage.Content>
   <map:SfMaps>
       <map:SfMaps.Layer>
           <map:MapTileLayer x:Name="layer"
                             UrlTemplate="https://tile.openstreetmap.org/{z}/{x}/{y}.png"
                             MarkerTemplate="{StaticResource markerTemplate}">
           </map:MapTileLayer>
       </map:SfMaps.Layer>
   </map:SfMaps>
</ContentPage.Content> 

Step 4: Add the MapMarker to the MapTileLayer’s MapMarkerCollection as shown in the following code sample.

XAML:

<map:MapTileLayer.Markers>
   <map:MapMarkerCollection x:Name="markers">
   	<map:MapMarker Latitude="20.766387"
                       Longitude="78.750000"/>
   </map:MapMarkerCollection>
</map:MapTileLayer.Markers> 

Step 5: Initialize the MapZoomPanBehavior of the MapTileLayer’s ZoomPanBehavior and set the EnableZooming property to True.

XAML:

<map:MapTileLayer.ZoomPanBehavior>
   <map:MapZoomPanBehavior EnableZooming="True" />
</map:MapTileLayer.ZoomPanBehavior> 

Step 6: In the MapTileLayer’s ZoomLevelChanging event, add and remove the markers from marker collection to achieve marker grouping based on the zoom level. In the following code sample, a single marker is maintained for Zoom levels 3 and below, and multiple markers are maintained for Zoom levels 4 and beyond.

C#:

private void Layer_ZoomLevelChanging(object sender, ZoomLevelChangingEventArgs e)
{
   if (e.NewZoomLevel <= 3 && markers.Count > 1)
   {
       markers.Clear();
       markers.Add(new MapMarker { Latitude = 20.766387, Longitude = 78.750000 });
   }
   else if (e.NewZoomLevel >= 4 && markers.Count == 1)
   {
       markers.Clear();
       markers.Add(new MapMarker { Latitude = 12.331952, Longitude = 78.002930 });
       markers.Add(new MapMarker { Latitude = 17.678045, Longitude = 78.793945 });
       markers.Add(new MapMarker { Latitude = 18.346705, Longitude = 73.608398 });
       markers.Add(new MapMarker { Latitude = 21.486297, Longitude = 84.418945 });
       markers.Add(new MapMarker { Latitude = 22.139076, Longitude = 72.905273 });
       markers.Add(new MapMarker { Latitude = 26.463197, Longitude = 81.166992 });
       markers.Add(new MapMarker { Latitude = 26.463197, Longitude = 74.487305 });
       markers.Add(new MapMarker { Latitude = 28.952879, Longitude = 77.915039 });
   }
} 

View the sample on GitHub.

Output:

When the zoom level is 1:

When the zoom level is 4:

Conclusion
I hope you enjoyed learning how to group the markers based on the zoom level in the .NET MAUI Maps (SfMaps).
Refer to our .NET MAUI Maps feature tour page to learn about its other groundbreaking feature representations. You can explore our .NET MAUI Maps documentation to understand how to present and manipulate data.
For current customers, check out our .NET MAUI components from the License and Downloads page. If you are new to Syncfusion, try our 30-day free trial to check out our .NET MAUI Maps and other .NET MAUI components.
Please let us know in the following comments section if you have any queries or require clarifications. Contact us through our support forums, Direct-Trac, or feedback portal. We are always happy to assist you!