Openlayers在OpenStreetMaps图层上圈出Polygon

Question

I'm trying to create a circle with a defined center and put an icon marker on it. 我正在尝试创建一个带有已定义中心的圆圈，并在其上放置一个图标标记。 The code is working if I use images instead of OpenLayers.Geometry.Polygon.createRegularPolygon. 如果我使用图像而不是OpenLayers.Geometry.Polygon.createRegularPolygon，代码正常工作。 I wasn't able to solve it. 我无法解决它。

here you find my code: 在这里你找到我的代码：

<html>
<head>
<title>OpenLayers Example</title>
<script src="http://www.openlayers.org/api/OpenLayers.js"></script>
</head>
<body>

<div id="mapdiv"></div>
<script>

map = new OpenLayers.Map("mapdiv");
map.addLayer(new OpenLayers.Layer.OSM());

epsg4326 =  new OpenLayers.Projection("EPSG:4326"); //WGS 1984 projection
projectTo = map.getProjectionObject(); //The map projection (Spherical Mercator)

var lonLat = new OpenLayers.LonLat( -0.1279688 ,51.5077286 ).transform(epsg4326,     projectTo);

var zoom=6;
map.setCenter (lonLat, zoom);

var mycircle = OpenLayers.Geometry.Polygon.createRegularPolygon(
               new OpenLayers.Geometry.Point( lonLat ),
               1,
               30
           );

var featurecircle = new OpenLayers.Feature.Vector(mycircle);


var vectorLayer = new OpenLayers.Layer.Vector("Overlay");

// Define markers as "features" of the vector layer:
vectorLayer.addFeatures(featurecircle);

var feature = new OpenLayers.Feature.Vector(
new OpenLayers.Geometry.Point( -0.1244324, 51.5006728  ).transform(epsg4326, projectTo),
        {description:'info'} ,
        {externalGraphic: 'img/marker.png', graphicHeight: 25, graphicWidth: 21,      graphicXOffset:-12, graphicYOffset:-25  }
    );    
vectorLayer.addFeatures(feature);


map.addLayer(vectorLayer);


</script>
</body>
</html>

Thanks in advance for any tips. 提前感谢任何提示。

Answer 1

OpenLayers.Geometry.Point constructor takes in x,y not lonlat obj. OpenLayers.Geometry.Point构造函数接受x，y而不是lonlat obj。 When you're creating the circle new OpenLayers.Geometry.Point( lonLat ) should be new OpenLayers.Geometry.Point(lonLat.lon, lonLat.lat); 当你创建圆圈时， new OpenLayers.Geometry.Point( lonLat )应该是new OpenLayers.Geometry.Point(lonLat.lon, lonLat.lat);

在此输入图像描述

This should work better: 这应该更好：

map = new OpenLayers.Map("mapdiv");
map.addLayer(new OpenLayers.Layer.OSM());
epsg4326 = new OpenLayers.Projection("EPSG:4326"); //WGS 1984 projection
projectTo = map.getProjectionObject(); //The map projection (Spherical Mercator)

var lonLat = new OpenLayers.LonLat(-0.1279688, 51.5077286).transform(epsg4326, projectTo);

var zoom = 6;
map.setCenter(lonLat, zoom);

var vectorLayer = new OpenLayers.Layer.Vector("Overlay");

var point = new OpenLayers.Geometry.Point(lonLat.lon, lonLat.lat);


var mycircle = OpenLayers.Geometry.Polygon.createRegularPolygon
(
    point,
    50000,
    40,
    0
);

var featurecircle = new OpenLayers.Feature.Vector(mycircle);

var featurePoint = new OpenLayers.Feature.Vector(
    point,
    { description: 'info' },
    { externalGraphic: 'img/marker.png', graphicHeight: 25, graphicWidth: 21, graphicXOffset: -12, graphicYOffset: -25 }
);
vectorLayer.addFeatures([featurePoint, featurecircle]);

map.addLayer(vectorLayer);

Answer 2

If you want to have your circle and your point combined together into one object then use OpenLayers.Geometry.Collection . 如果你想将你的圆和你的点组合成一个对象，那么使用OpenLayers.Geometry.Collection 。 Using this method you can apply some controls like DragFeature which will operate on elements in the collection at once. 使用此方法，您可以应用一些控件，如DragFeature，它将立即对集合中的元素进行操作。

var defaultStyle = new OpenLayers.Style({
    externalGraphic:'${icon}',
    graphicHeight: 25, 
    graphicWidth:  21,      
    graphicXOffset:-12, 
    graphicYOffset:-25
});
var styleMap = new OpenLayers.StyleMap({'default': defaultStyle });
var vectorLayer = new OpenLayers.Layer.Vector("Overlay",{styleMap: styleMap });

var aPoint  = new OpenLayers.Geometry.Point( lonLat.lon, lonLat.lat );
var aCircle = OpenLayers.Geometry.Polygon.createRegularPolygon( aPoint, 50000, 40, 0 );

var aCirclePoint = new OpenLayers.Geometry.Collection( [ aCircle, aPoint ] );
var aCirclePoint_feature = new OpenLayers.Feature.Vector( aCirclePoint );
aCirclePoint_feature.attributes = { icon:'/img/marker.png' }

vectorLayer.addFeatures( [ aCirclePoint_feature ] );

Openlayers在OpenStreetMaps图层上圈出Polygon

问题描述

2 个解决方案

解决方案1
18 2012-03-15 18:37:16

解决方案2
5 2012-08-29 20:08:02

Openlayers在OpenStreetMaps图层上圈出Polygon

问题描述

2 个解决方案

解决方案1 18 2012-03-15 18:37:16

解决方案2 5 2012-08-29 20:08:02

解决方案1
18 2012-03-15 18:37:16

解决方案2
5 2012-08-29 20:08:02