Pomoc w programowaniu, odpowiedzi na pytania / JavaScript / Jak wyświetlić szerokość i długość geograficzną z tego kodu za pomocą Openlayerów? - javascript, openlayers

Jak wyświetlić szerokość i długość geograficzną z tego kodu za pomocą Openlayerów? - javascript, openlayers

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<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>Drag Feature Example</title>

<link rel="stylesheet" href="../theme/default/style.css" type="text/css" />
<link rel="stylesheet" href="style.css" type="text/css" />
<style type="text/css">
#controls {
width: 512px;
}
#controlToggle {
padding-left: 1em;
}
#controlToggle li {
list-style: none;
}
</style>

<script src="../OpenLayers.js"></script>
<script type="text/javascript">
var map, vectors, controls;
function init(){
map = new OpenLayers.Map("map");
var wms = new OpenLayers.Layer.WMS( "OpenLayers WMS",
"http://vmap0.tiles.osgeo.org/wms/vmap0?", {layers: "basic"});

vectors = new OpenLayers.Layer.Vector("Vector Layer");

map.addLayers([wms, vectors]);
map.addControl(new OpenLayers.Control.LayerSwitcher());
map.addControl(new OpenLayers.Control.MousePosition());
//map.addControl(new OpenLayers.Control.Click());

controls = {
point: new OpenLayers.Control.DrawFeature(vectors,
OpenLayers.Handler.Point),

line: new OpenLayers.Control.DrawFeature(vectors,
OpenLayers.Handler.Path),
polygon: new OpenLayers.Control.DrawFeature(vectors,
OpenLayers.Handler.Polygon),
drag: new OpenLayers.Control.DragFeature(vectors)
};

for(var key in controls) {
map.addControl(controls[key]);
// map.addControl(click);
}

map.setCenter(new OpenLayers.LonLat(0, 0), 3);
document.getElementById("noneToggle").checked = true;
}

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()">
<h1 id="title">Drag Feature Example</h1>

<div id="tags">
point, line, linestring, polygon, digitizing, geometry, draw, drag
</div>

<p id="shortdesc">
Demonstrates point, line and polygon creation and editing.
</p>

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

<div id="controls">
<ul id="controlToggle">
<li>
<input type="radio" name="type" value="none" id="noneToggle"
onclick="toggleControl(this);" checked="checked" />

<label for="noneToggle">navigate</label>
</li>
<li>
<input type="radio" name="type" value="point" id="pointToggle" onclick="toggleControl(this);" />
<label for="pointToggle">draw point</label>
</li>
<li>
<input type="radio" name="type" value="line" id="lineToggle" onclick="toggleControl(this);" />

<label for="lineToggle">draw line</label>
</li>
<li>
<input type="radio" name="type" value="polygon" id="polygonToggle" onclick="toggleControl(this);" />
<label for="polygonToggle">draw polygon</label>
</li>
<li>
<input type="radio" name="type" value="drag" id="dragToggle"
onclick="toggleControl(this);" />

<label for="dragToggle">drag feature</label>
</li>
</ul>
</div>

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

Chcę wyświetlić szerokość i długość każdego kliknięcia myszą w polu tekstowym. Nie jestem w stanie zrozumieć skąd mam czerpać szerokość i długość geograficzną?

Odpowiedzi:

6 dla odpowiedzi № 1

Oto czego potrzebujesz:

map.events.register("click", map, function(e) {
var position = map.getLonLatFromPixel(e.xy);

OpenLayers.Util.getElement("mydiv").innerHTML =
position.lon.toFixed(3) + ", " + position.lat.toFixed(3);

});

Możesz zobaczyć tutaj działający kod: http://jsbin.com/uyuka6

Twój kod powinien wyglądać tak:

function init(){

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

vectors = new OpenLayers.Layer.Vector("Vector Layer");

map.addLayers([wms, vectors]);
map.addControl(new OpenLayers.Control.LayerSwitcher());
map.addControl(new OpenLayers.Control.MousePosition());
//map.addControl(new OpenLayers.Control.Click());

map.events.register("click", map, function(e) {
var position = map.getLonLatFromPixel(e.xy);

OpenLayers.Util.getElement("shortdesc").innerHTML =
position.lon.toFixed(3) + ", " + position.lat.toFixed(3);

});

controls = {
point: new OpenLayers.Control.DrawFeature(vectors,
OpenLayers.Handler.Point),

line: new OpenLayers.Control.DrawFeature(vectors,
OpenLayers.Handler.Path),
polygon: new OpenLayers.Control.DrawFeature(vectors,
OpenLayers.Handler.Polygon),
drag: new OpenLayers.Control.DragFeature(vectors)
};

var poly = controls["polygon"].handler;
poly.callbacks.point = function(point){
OpenLayers.Util.getElement("docs").innerHTML = point.toString();
};

var line = controls["line"].handler;
line.callbacks.point = function(point){
OpenLayers.Util.getElement("docs").innerHTML = point.toString();
};

for(var key in controls) {
map.addControl(controls[key]);
// map.addControl(click);
}

map.setCenter(new OpenLayers.LonLat(0, 0), 3);
document.getElementById("noneToggle").checked = true;
}