Javascript 如何绘制动画openlayers线串路径?
我正在使用openlaers映射api。我想在我的路径中显示动画路线,如下图所示。怎么做?多谢各位 这是我的Java脚本,我从XML文件中获取数据Javascript 如何绘制动画openlayers线串路径?,javascript,xml,openlayers,gpx,Javascript,Xml,Openlayers,Gpx,我正在使用openlaers映射api。我想在我的路径中显示动画路线,如下图所示。怎么做?多谢各位 这是我的Java脚本,我从XML文件中获取数据 <script type="text/javascript"> var zoom=13 var map; //complex object of type OpenLayers.Map function init() {
<script type="text/javascript">
var zoom=13
var map; //complex object of type OpenLayers.Map
function init() {
map = new OpenLayers.Map ("map", {
controls:[
new OpenLayers.Control.Navigation(),
new OpenLayers.Control.PanZoomBar(),
new OpenLayers.Control.LayerSwitcher(),
new OpenLayers.Control.Attribution()],
maxExtent: new OpenLayers.Bounds(-20037508.34,-20037508.34,20037508.34,20037508.34),
maxResolution: 156543.0399,
numZoomLevels: 19,
units: 'm',
projection: new OpenLayers.Projection("EPSG:900913"),
displayProjection: new OpenLayers.Projection("EPSG:4326")
} );
// Define the map layer
// Here we use a predefined layer that will be kept up to date with URL changes
layerMapnik = new OpenLayers.Layer.OSM.Mapnik("Mapnik");
map.addLayer(layerMapnik);
layerCycleMap = new OpenLayers.Layer.OSM.CycleMap("CycleMap");
map.addLayer(layerCycleMap);
layerMarkers = new OpenLayers.Layer.Markers("Markers");
map.addLayer(layerMarkers);
// Add the Layer with the GPX Track
var lgpx = new OpenLayers.Layer.Vector("Descrizione del layer", {
strategies: [new OpenLayers.Strategy.Fixed()],
protocol: new OpenLayers.Protocol.HTTP({
url: "c.php",
format: new OpenLayers.Format.GPX()
}),
style: {strokeColor: "blue", strokeWidth: 5, strokeOpacity: 0.5},
projection: new OpenLayers.Projection("EPSG:4326")
});
map.addLayer(lgpx);
}
</script>
变焦值=13
var映射//OpenLayers.Map类型的复杂对象
函数init(){
map=新的OpenLayers.map(“map”{
控制:[
新建OpenLayers.Control.Navigation(),
新建OpenLayers.Control.PanZoomBar(),
新建OpenLayers.Control.LayerSwitcher(),
新建OpenLayers.Control.Attribute(),
maxExtent:new OpenLayers.Bounds(-20037508.34,-20037508.3420037508.3420037508.34),
最大分辨率:156543.0399,
numZoomLevels:19,
单位:'m',
投影:新OpenLayers.projection(“EPSG:900913”),
displayProjection:new OpenLayers.Projection(“EPSG:4326”)
} );
//定义地图图层
//在这里,我们使用一个预定义的层,该层将随着URL更改而保持最新
layerMapnik=新的OpenLayers.Layer.OSM.Mapnik(“Mapnik”);
map.addLayer(layerMapnik);
layerCycleMap=新的OpenLayers.Layer.OSM.CycleMap(“CycleMap”);
map.addLayer(layerCycleMap);
layerMarkers=新的OpenLayers.Layer.Markers(“Markers”);
地图。添加图层(图层标记);
//添加带有GPX轨迹的图层
var lgpx=new OpenLayers.Layer.Vector(“descripione del Layer”{
策略:[新建OpenLayers.Strategy.Fixed()],
协议:新OpenLayers.protocol.HTTP({
网址:“c.php”,
格式:新建OpenLayers.format.GPX()
}),
样式:{strokeColor:“蓝色”,strokeWidth:5,strokeOpacity:0.5},
投影:新OpenLayers.投影(“EPSG:4326”)
});
map.addLayer(lgpx);
}
请尝试下面的答案。这似乎很相似
以下是答案的重要部分:
time
参数指定希望动画持续多长时间
(以毫秒为单位),并且步骤指定所需的步骤数
将动画划分为多个部分fn
是将执行的回调
当动画完成时
function drawAnimatedLine(startPt, endPt, style, steps, time, fn) {
var directionX = (endPt.x - startPt.x) / steps;
var directionY = (endPt.y - startPt.y) / steps;
var i = 0;
var prevLayer;
var ivlDraw = setInterval(function () {
if (i > steps) {
clearInterval(ivlDraw);
if (fn) fn();
return;
}
var newEndPt = new OpenLayers.Geometry.Point(startPt.x + i * directionX, startPt.y + i * directionY);
var line = new OpenLayers.Geometry.LineString([startPt, newEndPt]);
var fea = new OpenLayers.Feature.Vector(line, {}, style);
var vec = new OpenLayers.Layer.Vector();
vec.addFeatures([fea]);
map.addLayer(vec);
if(prevLayer) map.removeLayer(prevLayer);
prevLayer = vec;
i++;
}, time / steps);
}