Openlayers中的KML层不适用于localhost

Question

I have strange problem with rendering KML file in OpenLayers. 我在OpenLayers中渲染KML文件时遇到了奇怪的问题。 It seems to be easy, but it's not. 这似乎很容易，但事实并非如此。 I've started with an example from here OpenLayers example . 我从这里的OpenLayers示例开始。 I wanted to add my own KML. 我想添加自己的KML。 It didn't work. 它没用。 I've created a local copy of the example with absolute urls, as follows: 我已经使用绝对URL创建了示例的本地副本，如下所示：

<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0">
    <meta name="apple-mobile-web-app-capable" content="yes">
    <link rel="stylesheet" href="http://openlayers.org/dev/theme/default/style.css" type="text/css" />
    <link rel="stylesheet" href="http://openlayers.org/dev/examples/style.css" type="text/css" />
    <script src="http://openlayers.org/dev/OpenLayers.js"></script>            
    <style type="text/css">
        html, body {
            height: 100%;
        }
        #map {
            width: 100%;
            height: 80%;
            border: 1px solid black;
        }
        .olPopup p { margin:0px; font-size: .9em;}
        .olPopup h2 { font-size:1.2em; }
    </style>
    <script type="text/javascript">


        var lon = 5;
        var lat = 40;
        var zoom = 5;
        var map, select;

        function init(){
            map = new OpenLayers.Map('map');

            var wms = new OpenLayers.Layer.WMS(
                "OpenLayers WMS",
                "http://vmap0.tiles.osgeo.org/wms/vmap0",
                {layers: 'basic'}
            );

            var sundials = new OpenLayers.Layer.Vector("KML", {
                projection: map.displayProjection,
                strategies: [new OpenLayers.Strategy.Fixed()],
                protocol: new OpenLayers.Protocol.HTTP({
                    url: "http://openlayers.org/dev/examples/kml/sundials.kml",
                    format: new OpenLayers.Format.KML({
                        extractStyles: true,
                        extractAttributes: true
                    })
                })
            });

            map.addLayers([wms, sundials]);
            alert("deded");
            select = new OpenLayers.Control.SelectFeature(sundials);

            sundials.events.on({
                "featureselected": onFeatureSelect,
                "featureunselected": onFeatureUnselect
            });

            map.addControl(select);
            select.activate();   
            map.zoomToExtent(new OpenLayers.Bounds(68.774414,11.381836,123.662109,34.628906));
        }
        function onPopupClose(evt) {
            select.unselectAll();
        }
        function onFeatureSelect(event) {
            var feature = event.feature;
            // Since KML is user-generated, do naive protection against
            // Javascript.
            var content = "<h2>"+feature.attributes.name + "</h2>" + feature.attributes.description;
            if (content.search("<script") != -1) {
                content = "Content contained Javascript! Escaped content below.<br>" + content.replace(/</g, "&lt;");
            }
            popup = new OpenLayers.Popup.FramedCloud("chicken", 
                                     feature.geometry.getBounds().getCenterLonLat(),
                                     new OpenLayers.Size(100,100),
                                     content,
                                     null, true, onPopupClose);
            feature.popup = popup;
            map.addPopup(popup);
        }
        function onFeatureUnselect(event) {
            var feature = event.feature;
            if(feature.popup) {
                map.removePopup(feature.popup);
                feature.popup.destroy();
                delete feature.popup;
            }
        }
    </script>
  </head>
  <body onload="init()">
      <h1 id="title">KML Layer Example</h1>

      <div id="tags">
          kml, popup, feature
      </div>

      <p id="shortdesc">
          Demonstrates loading and displaying a KML file on top of a basemap.
    </p>

    <div id="map" class="smallmap"></div>

    <div id="docs"></div>
  </body>
</html>

It doesn;t render. 它没有渲染。 I tried to change KML url to my local copy of sundial.kml ( url: "http://openlayers.org/dev/examples/kml/sundials.kml", -> url: "/sundials.kml , and it didn't work either. I don't have Idea why. 我试图将KML url更改为我的sundial.kml本地副本（ url: "http://openlayers.org/dev/examples/kml/sundials.kml", -> url: "/sundials.kml ，它没有也没办法。我没有想法为什么。

Finally I want to add my own KML files, but they do not show either. 最后我想添加自己的KML文件，但它们也没有显示。 What should I do? 我该怎么办？

Thanks in advance Rafal 在此先感谢拉法尔

Answer 1

The reason that your local copy of sundials.kml won't render is that you're using OpenLayers.Protocol.HTTP , which won't load an address of the kind file://directory/file.kml . 您的sundials.kml本地副本无法呈现的原因是您使用的是OpenLayers.Protocol.HTTP ，它不会加载类型file://directory/file.kml的地址file://directory/file.kml 。

But I've no idea why your posted code doesn't render. 但我不知道为什么你发布的代码不呈现。 I'm currently wrestling with the same problem. 我目前正在努力解决同样的问题。 All I can tell you is what else doesn't work. 我能告诉你的是其他什么都行不通。

The Openlayers documentation explains how a GML layer can be used to load a KML layer. Openlayers文档解释了如何使用GML图层加载KML图层。 Unfortunately, the code snippet they give in the documentation doesn't match their actual example , which uses a Vector layer just like most of their other KML (and GML) examples. 不幸的是，他们在文档中提供的代码片段与他们的实际示例不匹配，后者使用Vector层就像大多数其他KML（和GML）示例一样。

I copied the example code anyway, but changed the Vector layer to var layer = new OpenLayers.Layer.GML("GML", "gml/polygon.xml"); 我无论如何都复制了示例代码，但将Vector层更改为var layer = new OpenLayers.Layer.GML("GML", "gml/polygon.xml"); , as per the documentation. ，根据文件。 Then I made local copies of Openlayers.js, polygon.xml and the .css stylesheets, and changed the urls to point to my local copies. 然后我制作了Openlayers.js，polygon.xml和.css样式表的本地副本，并将URL更改为指向我的本地副本。 So everything is local. 所以一切都是本地的。

<!DOCTYPE html> 
<html> 
    <head> 
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 
        <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0"> 
        <meta name="apple-mobile-web-app-capable" content="yes"> 
        <title>GML Doesn't Render</title> 
        <link rel="stylesheet" href="defaultstyle.css" type="text/css"> 
        <link rel="stylesheet" href="examplesstyle.css" type="text/css"> 
        <script src="OpenLayers.js"></script> 
        <script type="text/javascript">
            var map;

            function init(){
                map = new OpenLayers.Map('map');
                var wms = new OpenLayers.Layer.WMS(
                    "OpenLayers WMS", "http://vmap0.tiles.osgeo.org/wms/vmap0",
                    {layers: 'basic'}
                );

                var layer = new OpenLayers.Layer.GML("GML", "gml/polygon.xml");

                map.addLayers([wms, layer]);
                map.zoomToExtent(new OpenLayers.Bounds(
                    -3.92, 44.34, 4.87, 49.55
                ));
            }
        </script> 
    </head> 
    <body onload="init()"> 
        <div id="map" class="smallmap"></div> 
    </body> 
</html>

It doesn't work. 它不起作用。

I also tried the suggestion from the documentation: 我也尝试了文档中的建议：

var layer = new OpenLayers.Layer.GML("KML", "kml/lines.kml", {
   format: OpenLayers.Format.KML,
   formatOptions: {
       'extractStyles': true
   }
});

It doesn't work. 它不起作用。

There is even a specific example of loading "locally stored GML vector data on a basemap". 甚至存在将“本地存储的GML矢量数据加载到底图上”的特定示例。 It uses the same code as the documentation, so, needless to say, it doesn't work. 它使用与文档相同的代码，因此，不用说，它不起作用。 I can't hyperlink to it because I haven't enough reputation yet to make three hyperlinks, but you can find it if you search the examples for "GML". 我无法超链接到它，因为我还没有足够的声誉来制作三个超链接，但如果你搜索“GML”的例子，你可以找到它。

Openlayers has a security feature to make it difficult to load data and javascript from wildly different locations (and a workaround called "proxyhost" if you really have to do this). Openlayers具有安全功能，使得从异常不同的位置加载数据和javascript变得困难（如果你真的必须这样做，则称为“proxyhost”的解决方法）。 But I can't see how that would get involved when all the urls point to the localhost. 但是，当所有网址指向localhost时，我无法看到它会如何参与。

Please be gentle, this is my first post! 请温柔，这是我的第一篇文章！

EDIT: It turns out that a) it's a browser security feature, not OpenLayers, and b) it doesn't allow a script on the localhost to load any other file on the localhost, even if you're offline. 编辑：事实证明，a）它是一个浏览器安全功能，而不是OpenLayers，和b）它不允许localhost上的脚本加载localhost上的任何其他文件，即使您处于脱机状态。 Chrome/Chromium has a command-line parameter -allow-file-access-from-files. Chrome / Chromium有一个命令行参数-allow-file-access-from-files。 Using this parameter, the above examples work. 使用此参数，上述示例有效。 Other workarounds (Google them) seem tricky. 其他解决方法（谷歌他们）似乎很棘手。

Answer 2

This thread is old but I know it will still be looked at. 这个帖子已经过时但我知道它仍然会被看到。

Try setting the projection when creating the KML layer. 尝试在创建KML图层时设置投影。 That worked for me. 这对我有用。

    var kmllayer = new OpenLayers.Layer.Vector("KML", {
            projection: map.displayProjection,

Openlayers中的KML层不适用于localhost

问题描述

2 个解决方案

解决方案1
9 已采纳 2011-09-10 07:49:27

解决方案2
0 2015-01-22 19:14:25

Openlayers中的KML层不适用于localhost

问题描述

2 个解决方案

解决方案1 9 已采纳 2011-09-10 07:49:27

解决方案2 0 2015-01-22 19:14:25

解决方案1
9 已采纳 2011-09-10 07:49:27

解决方案2
0 2015-01-22 19:14:25