Change Transparency of Layer in MapService

Question

Hi, I'm trying to change the transparency of a layer in a map service. I have looked at examples and have tried different things but nothing seems to change the transparency. What am I missing?

map = new Map("map", {

basemap: "streets",

center: [-117.42330, 47.751103],

zoom: 11

});

var roadLayer = new esri.layers.ArcGISDynamicMapServiceLayer("http://gisappserv3/ArcGIS/rest/services/SCOUT/ENGINEERINGqueries/MapServer",

{

id: "roadLayer",

visible: true

});

roadLayer.setVisibleLayers([28]);

map.addLayers([roadLayer]);

var optionsArray = [];

var drawingOptions = new LayerDrawingOptions();

drawingOptions.transparency = 50;

optionsArray[28] = drawingOptions;

map.roadLayer.setLayerDrawingOptions(optionsArray);

TracySchloss · Answer

I've been using setOpacity and I've used this on both dynamic map services as well as feature layers. I have a dojo horizontal slider defined as:

Parcel Transparency

I have a listener associated with it: on(registry.byId('parcelOpacity'), 'change', changeOpacity); This is the function: function changeOpacity(op) { status_stateOwnParcelLayer.setOpacity(op);//this is an ArcGISDynamicMapServiceLayer stateOwnFeatureLayer.setOpacity(op);//this is a featureLayer }

YueWu1 · Answer

Hi John,

Make sure that the server you pointing to in your snippet http://gisappserv3/ArcGIS/rest/services/SCOUT/ENGINEERINGqueries/MapServer

is turn on Supports Dynamic Layers to true

You might already saw this sample: Change attribute used for a renderer | ArcGIS API for JavaScript  check their server that used has already turn on the Dynmaic Layer: Census (MapServer)

Here is the reference about how to Enabling dynamic layers on a map service in ArcGIS for Desktop—Help | ArcGIS for Desktop

Hope this can help!

thejuskambi · Answer

To be able to change the layer transparency at runtime. The map service should be enabled for Dynamic service. Please check the same.