[英]Show OpenLayers bounds after creating a circle
我已經制作了一個OpenLayers地圖。
我在地圖上做了兩個功能。
導航
繪制多邊形
我為多邊形制作了40個面,結果是一個圓。 繪制圓后,我想顯示圓的邊界框的坐標。 因此,在繪制一個圓之后,我希望能夠在ALERT BOX中顯示該圓的頂部,左側,底部和右側坐標?
我的代碼附在下面:
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<style type="text/css">
html, body, #map {
margin: 0;
width: 100%;
height: 100%;
}
</style>
<style type="text/css">
#controls {
width: 512px;
position: absolute;
bottom: 1em;
left: 1em;
width: 512px;
z-index: 20000;
background-color: white;
padding: 0 0.5em 0.5em 0.5em;
}
#controlToggle {
padding-left: 1em;
}
#controlToggle li {
list-style: none;
}
</style>
<script src="js/firebug.js"></script>
<script src="http://www.openlayers.org/dev/OpenLayers.js"></script>
<script type="text/javascript">
var lon = 24.0000000000;
var lat = -29.000000000000;
var zoom = 4;
var map, layer, vectors, controls;
function init(){
// Because the Streetmaps system uses 300x300 tiles, we need to set up the scaling variables to work with these
var aRes = [90,45,22.500000,11.250000,5.625000,2.812500,1.406250,0.703125,0.351563,0.175781,0.087891,0.043945, 0.021973,0.010986,0.005493,0.002747,0.001373,0.000687,0.000343];
for (var l=0;l<aRes.length;l++) {
aRes[l] = aRes[l]/300;
}
// Normal init, but we pass through the info about the zoom/scaling as options
map = new OpenLayers.Map( 'map',
{
tileSize: new OpenLayers.Size(300, 300),
projection: 'CRS:84',
numZoomLevels: aRes.length,
resolutions:aRes,
maxResolution:360/300
});
// At this point the control is used as per normal
layer1 = new OpenLayers.Layer.WMS(
'Streetmaps Streets',
'http://www.streetmaps.co.za/WMS/?',
{
key: 'HZPGNWPNDYPREPTIKSIHWKYKQYYOQVYX',
service: 'WMS',
request: 'GetMap',
version: '1.3.0',
layers: 'sm.maps.tiled',
format: 'image/png'
}
);
layer2 = new OpenLayers.Layer.WMS(
'Streetmaps Imagery',
'http://www.streetmaps.co.za/WMS/?',
{
key: 'HZPGNWPNDYPREPTIKSIHWKYKQYYOQVYX',
service: 'WMS',
request: 'GetMap',
version: '1.3.0',
layers: 'sm.imagery',
format: 'image/png'
}
);
// This loads the map
map.addLayer(layer1);
map.addLayer(layer2);
map.setCenter(new OpenLayers.LonLat(lon, lat), zoom);
map.addControl( new OpenLayers.Control.LayerSwitcher() );
var vectors = new OpenLayers.Layer.Vector("vector", {isBaseLayer: true});
map.addLayers([vectors]);
// This loads the overlays
var wmsLayer = new OpenLayers.Layer.WMS( "OpenLayers WMS",
"http://vmap0.tiles.osgeo.org/wms/vmap0?", {layers: 'basic'});
var polygonLayer = new OpenLayers.Layer.Vector("Polygon Layer");
map.addLayers([wmsLayer, polygonLayer]);
map.addControl(new OpenLayers.Control.LayerSwitcher());
map.addControl(new OpenLayers.Control.MousePosition());
polyOptions = {sides: 40};
polygonControl = new OpenLayers.Control.DrawFeature(polygonLayer,
OpenLayers.Handler.RegularPolygon,
{handlerOptions: polyOptions});
map.addControl(polygonControl);
document.getElementById('noneToggle').checked = true;
document.getElementById('irregularToggle').checked = false;
}
function setOptions(options) {
polygonControl.handler.setOptions(options);
}
function toggleControl(element) {
for(key in controls) {
var control = controls[key];
if(element.value == key && element.checked) {
control.activate();
} else {
control.deactivate();
}
}
}
</script>
</head>
<body onLoad="init()">
<div id="map" class="smallmap"></div>
<div id="controls">
<ul id="controlToggle">
<li>
<input type="radio" name="type"
value="none" id="noneToggle"
onclick="polygonControl.deactivate()"
checked="checked" />
<label for="noneToggle">navigate</label>
</li>
<li>
<input type="radio" name="type"
value="polygon" id="polygonToggle"
onclick="polygonControl.activate()" />
<label for="polygonToggle">draw polygon</label>
</li>
</ul>
</div>
</div>
</body>
</html>
我絕對不是OpenLayers的專家,很高興被真正了解OpenLayers的讀者改正,但是...
創建DrawFeature控件時,如果替換
{handlerOptions: polyOptions}
與
{handlerOptions: polyOptions, featureAdded: noteAdded}
並定義沿這些行添加的noteAdded
function noteAdded(f) {
alert(f.geometry.getBounds());
}
那么您將確切地收到您要的通知。 通常,傳遞給由featureAdded
指定的功能的是功能對象。 在這種情況下,它是一個OpenLayers.Feature.Vector
其geometry
屬性包含有關多邊形的所有信息。
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