Map units are the first loaded layer units.Until ESRI developers complete reference (or fix bugs), you can use first layer units:<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
xmlns:esri="http://www.esri.com/2008/ags">
<s:layout>
<s:VerticalLayout />
</s:layout>
<fx:Script>
<![CDATA[
import com.esri.ags.layers.ArcGISDynamicMapServiceLayer;
import com.esri.ags.layers.Layer;
import mx.collections.ArrayCollection;
import mx.controls.Alert;
protected function button1_clickHandler(event:MouseEvent):void
{
var layer:Layer = getMapFirstLayer();
if (layer != null)
{
var message:String = "";
if (layer is ArcGISTiledMapServiceLayer)
{
message = "Map units are: '" + ArcGISTiledMapServiceLayer(layer).units + "' - the first loaded layer units";
}
else if (layer is ArcGISDynamicMapServiceLayer)
{
message = "Map units are: '" + ArcGISDynamicMapServiceLayer(layer).units + "' - the first loaded layer units";
}
Alert.show(message, "Map units");
}
}
private function getMapFirstLayer():Layer
{
if (map != null)
{
var mapLayers:ArrayCollection = map.layers as ArrayCollection;
if (mapLayers != null && mapLayers.length > 0)
{
return mapLayers.getItemAt(0) as Layer;
}
}
return null;
}
]]>
</fx:Script>
<s:Button label="Show map units" click="button1_clickHandler(event)" />
<esri:Map id="map">
<esri:ArcGISTiledMapServiceLayer url="http://server.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer"/>
</esri:Map>
</s:Application>