Adding custom markers dynamically to map using OpenLayers
I would like to let users add custom markers on a map with a description for each marker. Any tips, links to a开发者_运维问答ny tutorials would be really useful.
You can register a function to 'click' event on your map. When the user click on it, the mark is added automatically.
Try something like this:
// 'map' is your map created using new OpenLayers.Map(options)
markers = new OpenLayers.Layer.Markers( "Markers" );
markers.id = "Markers";
map.addLayer(markers);
map.events.register("click", map, function(e) {
//var position = this.events.getMousePosition(e);
var position = map.getLonLatFromPixel(e.xy);
var size = new OpenLayers.Size(21,25);
var offset = new OpenLayers.Pixel(-(size.w/2), -size.h);
var icon = new OpenLayers.Icon('images/mark.png', size, offset);
var markerslayer = map.getLayer('Markers');
markerslayer.addMarker(new OpenLayers.Marker(position,icon));
});
Pretty simple, but I think that you can understand it :)
i tried @Fran 's solution but it didnt work for me. so i adapted this example from openlayers so that i could accomplish 2 things:
- save latitude and longitude of marker position
place a marker by clicking on the openlayers map
<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml" debug="true"> <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>MousePosition Control</title> <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="../OpenLayers.js"></script> <script type="text/javascript"> var map; function init(){ var map = new OpenLayers.Map('map'); var proj4326 = new OpenLayers.Projection("EPSG:4326"); var projmerc = new OpenLayers.Projection("EPSG:900913"); var layerOSM = new OpenLayers.Layer.OSM("Street Map"); map.addLayers([layerOSM]); if (!map.getCenter()) map.zoomToMaxExtent(); map.events.register("mousemove", map, function(e) { var position = this.events.getMousePosition(e); OpenLayers.Util.getElement("coords").innerHTML = 'MOUSE POSITION '+position; var lonlat = map.getLonLatFromPixel( this.events.getMousePosition(e) ); OpenLayers.Util.getElement("lonlatTG").innerHTML = 'lonlat => '+lonlat; var lonlatTransf = lonlat.transform(map.getProjectionObject(), proj4326); OpenLayers.Util.getElement("lonlatTrans").innerHTML = 'lonlatTransf => '+lonlatTransf; OpenLayers.Util.getElement("lonlatDouble").innerHTML = 'lonlat => '+lonlat; }); map.events.register("click", map, function(e) { var position = this.events.getMousePosition(e); var icon = new OpenLayers.Icon('http://maps.google.com/mapfiles/ms/icons/red-pushpin.png'); var lonlat = map.getLonLatFromPixel(position); var lonlatTransf = lonlat.transform(map.getProjectionObject(), proj4326); alert ('lonlatTrans=> lat='+lonlatTransf.lat+' lon='+lonlatTransf.lon+'\nlonlat=>'+lonlat+'\nposition=>'+position); var lonlat = lonlatTransf.transform(proj4326, map.getProjectionObject()); var markerslayer = new OpenLayers.Layer.Markers( "Markers" ); markerslayer.addMarker(new OpenLayers.Marker(lonlat, icon)); map.addLayer(markerslayer); }); map.addControl(new OpenLayers.Control.LayerSwitcher()); } </script> </head> <body onload="init()"> <h1 id="title">MousePosition Control</h1> <div id="tags">coordinate</div> <p>Click on map and create marker</p> <div id="map" class="smallmap"></div> <div id="coords"></div> <div id="lonlatTG"></div> <div id="lonlatTrans"></div><br/> <p> see how, even though we did NOT transform [lonlat], <br/>it was nevertheless transformed </p> <div id="lonlatDouble"></div> </body> </html>
there is something that you need to be aware of regarding the TRANSFORM method for LonLat as used in this simple example: when you apply [ .transform(projection1, projection2) ] to any LonLat, ALL LonLat objects are transformed.
play around with the order of certain commands and you will see what i mean.
for draggable markers, this example has it all
加载中,请稍侯......
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