OpenLayers在多个矢量图层编辑要素

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <title>在多个矢量图层编辑要素</title>
    <link rel="stylesheet" href="./OpenLayers-2.12/theme/default/style.css" type="text/css" />
    <script src="./OpenLayers-2.12/lib/OpenLayers.js"></script>
    <script type="text/javascript">
        function init(){
            // Create map
        var map = new OpenLayers.Map("editing_vector");
        var osm = new OpenLayers.Layer.OSM();
        map.addLayer(osm);
        map.addControl(new OpenLayers.Control.LayerSwitcher());
        map.setCenter(new OpenLayers.LonLat(0, 0), 3);

        var vectorLayerA = new OpenLayers.Layer.Vector("Vector layer A");
        var vectorLayerB = new OpenLayers.Layer.Vector("Vector layer B");
        map.addLayers([vectorLayerA, vectorLayerB]);

        var editingToolbarControl = new OpenLayers.Control.EditingToolbar(vectorLayerA);
        map.addControl(editingToolbarControl);

        function layerAChanged(checked) {
            if(checked) {
                var controls = editingToolbarControl.getControlsByClass("OpenLayers.Control.DrawFeature");
                for(var i=0; i< controls.length; i++) {
                    controls[i].layer = vectorLayerA;
                }
            }
        }
        function layerBChanged(checked) {
            if(checked) {
                var controls = editingToolbarControl.getControlsByClass("OpenLayers.Control.DrawFeature");
                for(var i=0; i< controls.length; i++) {
                    controls[i].layer = vectorLayerB;
                }
            }
        }
    }
    </script>
</head>
<body onload="init()">

    <form action="">
        Vector Layer A: <input id="rbA" type="radio"  onChange="layerAChanged" name="layer" value="layerA" checked/>
        Vector Layer B: <input id="rbB" type="radio"  onChange="layerBChanged" name="layer" value="layerB"/>
    </form>
    <div id="editing_vector" style="width: 100%; height: 100%;"></div>
</html>