下面显示的代码片段 (HTML5/javascript) 加载 Microsoft Bing 地图( VirtualEarth 6.3 ),然后添加两个 Shape 图层和两个示例图钉,每个图层一个。
问题:使用什么纯javascript函数(或解决方案)来清除第一层的所有图钉,保持另一层完好无损? 注意:清除图层功能应在不删除整个图层的情况下实现。
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Bing VE Map w/layers</title>
<script type="text/javascript" src="http://ecn.dev.virtualearth.net/mapcontrol/mapcontrol.ashx?v=6.3"></script>
<script type="text/javascript">
// VE map
var _map;
// 1st shape layer
var _layer1 ;
// 2nd shape layer
var _layer2;
function MapLoad() {
// load map
_map = new VEMap('Map');
_map.LoadMap();
// center point (Columbus Circle NY)
var _center = new VELatLong(40.7681, -73.9819);
// set center point and initial zoom level
_map.SetCenterAndZoom(_center, 12);
// set Map style
_map.SetMapStyle(VEMapStyle.Shaded);
// add 1st shape layer1 to Map obj
_layer1 = new VEShapeLayer()
_map.AddShapeLayer(_layer1);
// add 2nd shape layer2 to Map obj
_layer2 = new VEShapeLayer()
_map.AddShapeLayer(_layer2);
// add pushpin to layer1
var _pushpin1 = new VEShape(VEShapeType.Pushpin, _center);
_layer1.AddShape(_pushpin1);
// add pushpin (Apple Store on 5th) to layer2
var _pushpin2 = new VEShape(VEShapeType.Pushpin, new VELatLong(40.7639, -73.9725));
_layer2.AddShape(_pushpin2);
// QUESTION: HOW TO CLEAR ALL SHAPES FROM LAYER 1, (BUT NOT DELETING THE ENTIRE LAYER)?
}
</script>
</head>
<body onload="MapLoad();">
<div id="Map" style="position:absolute; top:100px; height:90%; width:100%;"></div>
</body>
</html>