Map reference scale

Set the map's reference scale and which feature layers should honor the reference scale.

Use case

Setting a reference scale on a Map fixes the size of symbols and text to the desired height and width at that scale. As you zoom in and out, symbols and text will increase or decrease in size accordingly. When no reference scale is set, symbol and text sizes remain the same size relative to the MapView.

Map annotations are typically only relevant at certain scales. For instance, annotations to a map showing a construction site are only relevant at that construction site's scale. So, when the map is zoomed out that information shouldn't scale with the MapView, but should instead remain scaled with the Map.

How to use the sample

Use the control at the top to set the map's reference scale (1:500,000 1:250,000 1:100,000 1:50,000). Use the menu checkboxes in the layer menu to set which feature layers should honor the reference scale.

How it works

1. Get and set the reference scale property on the Map object.
2. Get and set the scale symbols property on each individual FeatureLayer object.

Relevant API

• FeatureLayer
• Map

Additional information

The map reference scale should normally be set by the map's author and not exposed to the end user like it is in this sample.

Tags

map, reference scale, scene

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using Microsoft.UI.Xaml.Data;
using System;

namespace ArcGISRuntime.WinUI.Samples.MapReferenceScale
{
    internal class DoubleToScaleStringConverter : IValueConverter
    {
        // Converts a double to a string
        public object Convert(object value, Type targetType, object parameter, string language)
        {
            return $"1:{value:n0}";
        }

        public object ConvertBack(object value, Type targetType, object parameter, string language)
        {
            throw new NotImplementedException();
        }
    }
}