networking中OpenLayers:显示远程kml

我试图让 OpenLayers 显示从服务器检索的 KML 文件。 由于某种原因，这不起作用。 已提出类似的问题，但我找不到有效的示例。 我所做的是改进 OpenLayers 发行版中的示例之一:kml-track.js

我用我的发现改进了它。这就是它的样子。我觉得我错过了一些明显的东西。 欢迎大家指点

var map ; 
 
function init() { 
  var mercator = new OpenLayers.Projection("EPSG:900913"); 
  var geographic = new OpenLayers.Projection("EPSG:4326"); 
 
  //note that I have host equal to location//   //Math.Random will stop caching// 
  var mykmlurl = 'http://myserver/kml-track.kml'; 
 
  map = new OpenLayers.Map({ 
    div: "map", 
    projection: mercator, 
    layers: [ 
      new OpenLayers.Layer.OSM(), 
 
      //Defiine your KML layer// 
      new OpenLayers.Layer.Vector("This Is My KML Layer", { 
        //Set your projection and strategies// 
        projection: geographic, 
        strategies: [new OpenLayers.Strategy.Fixed()], 
        //set the protocol with a url// 
        protocol: new OpenLayers.Protocol.HTTP({ 
          //set the url to your variable// 
          url: mykmlurl, 
          //format this layer as KML// 
          format: new OpenLayers.Format.KML({ 
            //maxDepth is how deep it will follow network links// 
            maxDepth: 1, 
            //extract styles from the KML Layer// 
            extractStyles: true, 
            //extract attributes from the KML Layer// 
            extractAttributes: true 
          }) 
        }), 
        styleMap: new OpenLayers.StyleMap({ 
          "default": new OpenLayers.Style({ 
            graphicName: "circle", 
            pointRadius: 2, 
            fillOpacity: 0.5, 
            fillColor: "#ffcc66", 
            strokeColor: "#666633", 
            strokeWidth: 1 
          }) 
        }) 
      }) 
    ], 
    center: new OpenLayers.LonLat(-93.2735, 44.8349).transform(geographic, mercator), 
    zoom: 8 
  }); 
 
 
 //function called// //timer// //layer to refresh// 
  window.setInterval(UpdateKmlLayer, 5000, MyKmlLayer); 
} 
 
function UpdateKmlLayer(layer) { 
  //setting loaded to false unloads the layer// 
  layer.loaded = false; 
  //setting visibility to true forces a reload of the layer// 
  layer.setVisibility(true); 
  //the refresh will force it to get the new KML data// 
  layer.refresh({ force: true, params: { 'key': Math.random()} }); 
} 

请您参考如下方法:

这是如何在 OpenLayers 中显示 KML 图层的示例，可能会对您有所帮助:

http://openlayers.org/dev/examples/kml-layer.html

打开页面时是否遇到任何错误 - 或者运行正常但没有任何显示？如果您没有收到任何错误，则可能表明您的投影设置方式存在问题(即您的功能可能不会出现在您期望的位置)