topic Re: Setting alpha on individual layers in ArcGIS API for Flex Questions

Setting alpha on individual layers

BrendanLee — Tue, 13 Jul 2010 16:10:59 GMT

Is there a way to set the alpha on individual layers?
In the code below I would like to set the alpha for the first 2 to 100% and the 3rd to 60%.

<esri:ArcGISDynamicMapServiceLayer id="ElemZones" 
   url="http://myServer/ArcGIS/rest/services/public/Schools/MapServer"
   show="layerShowHandler(event)" alpha=".5"
   visible="{bb.selectedIndex == 1}"> 
     <esri:visibleLayers>
                <mx:ArrayCollection>
                 <mx:Number>3</mx:Number>
                  <mx:Number>4</mx:Number>
                  <mx:Number>5</mx:Number>
               </mx:ArrayCollection>
     </esri:visibleLayers>       
</esri:ArcGISDynamicMapServiceLayer>

Re: Setting alpha on individual layers

GregKnight — Sun, 12 Dec 2021 01:05:39 GMT

I think the way to approach this is to use 2 dynamic layers -- setting the alpha and visibility accordingly. Something like:

<esri:ArcGISDynamicMapServiceLayer id="ElemZones1" 
   url="http://myServer/ArcGIS/rest/services/public/Schools/MapServer"
   show="layerShowHandler(event)" alpha="1"
   visible="{bb.selectedIndex == 1}"> 
     <esri:visibleLayers>
                <mx:ArrayCollection>
                 <mx:Number>3</mx:Number>
                  <mx:Number>4</mx:Number>
               </mx:ArrayCollection>
     </esri:visibleLayers>       
</esri:ArcGISDynamicMapServiceLayer>

<esri:ArcGISDynamicMapServiceLayer id="ElemZones2" 
   url="http://myServer/ArcGIS/rest/services/public/Schools/MapServer"
   show="layerShowHandler(event)" alpha=".6"
   visible="{bb.selectedIndex == 1}"> 
     <esri:visibleLayers>
                <mx:ArrayCollection>
                  <mx:Number>5</mx:Number>
               </mx:ArrayCollection>
     </esri:visibleLayers>       
</esri:ArcGISDynamicMapServiceLayer>

Re: Setting alpha on individual layers

BrendanLee — Tue, 13 Jul 2010 20:33:42 GMT

Thanks for the reply. That's the approach I ended up using. I was just looking for a "cleaner" way to do it.