ArcGiS Api For JavaScript之图层标注

已被阅读 1612 次 | 文章分类:ArcGIS API For Javascript | 2018-03-01 21:15

在ArcGIS、MapGis、SuperMap、QGIS等桌面软件中，可以根据图层属性表中的某一个字段来标注图层，在web端也可以通过API来实现标注功能.本文实现简单的图层标注实例

一:代码实例

                                        
<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <meta name="viewport" content="initial-scale=1, maximum-scale=1, user-scalable=no">
    <title>Labeling features client-side</title>
    <link rel="stylesheet" href="https://js.arcgis.com/3.23/esri/css/esri.css">
    <style>
        html, body, #map {
            height: 100%;
            width: 100%;
            margin: 0;
            padding: 0;
        }
    </style>
    <script src="https://js.arcgis.com/3.23/"></script>
    <script>
      var map;
      require([
        "esri/map",
        "esri/geometry/Extent",
        "esri/SpatialReference",
        "esri/layers/FeatureLayer",      
        "esri/layers/LabelClass",
        "dojo/domReady!"
      ], function (
          Map,
          Extent,
          SpatialReference,
          FeatureLayer,
          LabelClass)
      {
        //定义extent实例对象，初始化地图初次显示的位置
        var startExtent = new Extent(73.141875, 19.564432, 137.606004, 55.465382, new SpatialReference({ "wkid": 4326 }));
        //定义map实例对象
        map = new Map("map", {
          extent: startExtent, 
          zoom: 4,
          showLabels: true   //此属性必须设置为true，才会展示标注
        });
        //定义FeatureLayer实例对象
        var ProvincesLayer = new FeatureLayer("http://localhost:6080/arcgis/rest/services/gisTutorial/ProvincesService/MapServer/0", { outFields: ["*"] });
        //定义标注实例对象
        var json = {
          "labelExpressionInfo": {"value": "{Name}"}    //以Name字段为标注字段
        };
        var labelClass = new LabelClass(json);
        //将标注实例对象添加到图层中
        ProvincesLayer.setLabelingInfo([labelClass]);
        //将图层实例添加到地图中
        map.addLayer(ProvincesLayer);
      });
    </script>
</head>
<body>
    <div id="map"></div>
</body>
</html>

二:运行效果

小白GIS

三:设置标注符号

通过API提供的"esri/symbols/TextSymbol"类，我们可以自定义显示标注的字体符号

四:代码实例

                                        
<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <meta name="viewport" content="initial-scale=1, maximum-scale=1, user-scalable=no">
    <title>Labeling features client-side</title>
    <link rel="stylesheet" href="https://js.arcgis.com/3.23/esri/css/esri.css">
    <style>
        html, body, #map {
            height: 100%;
            width: 100%;
            margin: 0;
            padding: 0;
        }
    </style>
    <script src="https://js.arcgis.com/3.23/"></script>
    <script>
      var map;
      require([
        "esri/map",
        "esri/geometry/Extent",
        "esri/SpatialReference",
        "esri/layers/FeatureLayer",
        "esri/symbols/TextSymbol",
        "esri/layers/LabelClass",
        "esri/Color",
        "dojo/domReady!"
      ], function (
          Map,
          Extent,
          SpatialReference,
          FeatureLayer,
          TextSymbol,
          LabelClass,
          Color)
      {
        //定义extent实例对象，初始化地图初次显示的位置
        var startExtent = new Extent(73.141875, 19.564432, 137.606004, 55.465382, new SpatialReference({ "wkid": 4326 }));
        //定义map实例对象
        map = new Map("map", {
          extent: startExtent, 
          zoom: 4,
          showLabels: true   //此属性必须设置为true，才会展示标注
        });
        //定义FeatureLayer实例对象
        var ProvincesLayer = new FeatureLayer("http://localhost:6080/arcgis/rest/services/gisTutorial/ProvincesService/MapServer/0", { outFields: ["*"] });
        //定义标注符号
        var LabelColor = new Color("#ff0d08");
        var Labelsymbol = new TextSymbol().setColor(LabelColor);
        Labelsymbol.font.setSize("11pt");
        Labelsymbol.font.setFamily("KaiTi");
        //定义标注实例对象
        var json = {
          "labelExpressionInfo": {"value": "{Name}"}    //以Name字段为标注字段
        };
        var labelClass = new LabelClass(json);
        labelClass.symbol = Labelsymbol;
        //将标注实例对象添加到图层中
        ProvincesLayer.setLabelingInfo([labelClass]);
        //将图层实例添加到地图中
        map.addLayer(ProvincesLayer);
      });
    </script>
</head>
<body>
    <div id="map"></div>
</body>
</html>

五:运行效果

小白GIS

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