javascript - 如何标记以编程方式生成的要素图层？

Question

我是 ESRI ArcGIS API for Javascript 的新手，我正在尝试以编程方式生成要素图层，然后向其添加标签图层。要素图层似乎可以工作，但标注图层没有提供任何输出（也没有错误）。有人可以告诉我我做错了什么吗？

jsfiddle：http: //jsfiddle.net/9X46z/

相关的javascript：

var layerDefinition = {
    "geometryType": "esriGeometryPoint",
    "fields": [
        {
            "name": "__OBJECTID",
            "alias": "__OBJECTID",
            "type": "esriFieldTypeOID",
        }, {
            "name": "testfield",
            "alias": "testfield",
            "type": "esriFieldTypeString"
        }
    ]
}

var featureCollection = {
    layerDefinition: layerDefinition,
    featureSet: null
};

var fl = new FeatureLayer(featureCollection, {
    id: "featurelayer",
    outFields: ["testfield"]
})

var m = new esri.Graphic(new esri.geometry.Point(-77, 40), pushpin);
m.attributes = {
    "testfield": "test value"
};

fl.add(m);

map.addLayer(fl);

// create a text symbol to define the style of labels
var testLabel = new TextSymbol().setColor(new Color("#666666"));
testLabel.font.setSize("14pt");
testLabel.font.setFamily("arial");
testLabelRenderer = new SimpleRenderer(testLabel);

var labels = new LabelLayer({
    id: "labels"
});
labels.addFeatureLayer(fl, testLabelRenderer, "{testfield}");
// add the label layer to the map
map.addLayer(labels);

Answer 1

这是一个有一个变化的更新版本：http: //jsfiddle.net/2WccC/1/

var m = new esri.Graphic(new esri.geometry.Point(-77, 40), pushpin);

到

var m = new esri.Graphic(esri.geometry.geographicToWebMercator(new esri.geometry.Point(-77, 40)), pushpin);

Answer 2

尝试在创建地图时将地图的 showLabels 选项设置为 true，默认情况下为 false。map = new Map("mapDiv", {showLabels: true });