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Openlayers3实现车辆轨迹回放功能.pdf
Openlayers3实现车辆轨迹回放功能
实现车辆轨迹回放功能
主要介绍了Openlayers3实现车辆轨迹回放功能，文中示例代码介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴
们可以参考一下
记录基于geoserver地图服务，Openlayers3在web前端实现车辆轨迹回放功能，并记录和解决过程中出现的linestring只描绘部分经纬度
坐标问题。
参考Openlayers3 官网例子
html
车辆轨迹回放
map初始化
$(document).ready(function () {
map = new ol.Map({
logo: false,
target: document.getElementById('map'),
layers: layers,
view: view
});
initSelect();//设备下拉框列表初始化
//时间控件初始化
$('#s-traceday').val(transfromTime(new Date(),false)+" 00:00:00");
$('#e-traceday').val(transfromTime(new Date(),true));
$('.datepicker').datetimepicker({
minView:0,
format: 'yyyy-MM-dd hh:mm:ss',
todayBtn : "linked",
autoclose : true,
todayHighlight : true,
startDate: daylimit,
endDate:'+1d'//结束时间，在这时间之后都不可选
});
});
//轨迹line layer
var vsource = new ol.source.Vector({
type: 'LineString',
features: []
});
var linelayers = new ol.layer.Vector({
source: vsource,
style: new ol.style.Style({
fill: new ol.style.Fill({
color: '#0044CC'
}),
stroke: new ol.style.Stroke({
color: '#0044CC',
width: 4
})
})
});
//地图基础参数
var map;
var center = [121.6606763113213, 31.14611063632111];
var lng, lat;
var source = new ol.source.Vector({
wrapX: false
});;
var projection = new ol.proj.Projection({
code: 'EPSG:4326',
units: 'degrees',
axisOrientation: 'neu'
});
var view = new ol.View({
projection: projection,
center: center,
zoom: 16
});
var layers = [new ol.layer.Tile({
title: '、地图',
visible: true,
preload: Infinity,
source: new ol.source.TileWMS({
url: gisUrl,
params: {
'VERSION': '1.1.0',
tiled: true,
STYLES: '',
LAYERS: 'shanghai:maptest',
}
})
}),linelayers];
ajax获取坐标数据
//轨迹查询按钮点击
var positions=[];
$("#queryBtn").click(function(){
//清除之前的图层
if (centerSource.getFeatures != null) {
centerSource.clear(); }
linelayers.getSource().clear(true);
positions=[];//清空
//取值
var busnum=$("#busSelect").val();
var traceday=$("#traceday").val();
if(busnum=="*"){
$(".remind").html('请先选择车辆');
return;
}else{
$(".remind").html('');
busnum=busnum.slice(2);
}
if(transfromTime(new Date(),false)==traceday){//当天
traceday="*";
}else{
traceday=traceday.replace(/(-)/g,"");
}
$(".remind").html(' 正在查询...');
//请求
$.getJSON(baseUrl+"trace/query/"+busnum+"/"+traceday,"",function(data){
if(data.length==0){
$(".remind").html('未查到gps数据');return;
}
var position = [];
for(var i = 0;i该车辆当天停在该位置未启动');
centerAt(positions[0]);
return;
}
AddLayer(positions);
});
});
显示轨迹
//轨迹描绘
function AddLayer() {
var lineFeature = new ol.Feature({//路线
geometry: new ol.geom.LineString(positions,'XY'),
});
linelayers.getSource().addFeature(lineFeature);
var startFeature = new ol.Feature({//起点
geometry: new ol.geom.Point(positions[0]),
population: 4000,
rainfall: 500
});
startFeature.setStyle(startStyle);
linelayers.getSource().addFeature(startFeature);
var endFeature = new ol.Feature({//终点
geometry: new ol.geom.Point(positions[positions.length-1]),
population: 4000,
rainfall: 500
});
endFeature.setStyle(endStyle);
linelayers.getSource().addFeature(endFeature);
carFeature = new ol.Feature({//车子
geometry: new ol.geom.Point(positions[0]),
population: 4000,
rainfall: 500
});
carFeature.setStyle(carStyle);
linelayers.getSource().addFeature(carFeature);
var extent = linelayers.getSource().getExtent();//合适比例缩放居中
view.fit(extent, map.getSize());
}
显示单点
//居中 车辆不运动时居中显示图标处理
var centerLayer = null;
var centerSource = new ol.source.Vector({
features: null
});
//居中在一个位置
function centerAt(position) {
var pan = ol.animation.pan({
duration: 2000,
source: (view.getCenter())
});
view.setCenter(position);
var iconFeature = new ol.Feature({
geometry: new ol.geom.Point(position),
name: 'Null Island',
population: 4000,
rainfall: 500
});
iconFeature.setStyle(iconStyle);
centerSource.addFeature(iconFeature);
centerLayer = new ol.layer.Vector({
source: centerSource
});
map.addLayer(centerLayer);
centerLayer.setVisible(true);
}
点在线上运动，轨迹回放
//轨迹回放start 参考官网
var carFeature = null;
var speed, now;
var animating = false;
$("#animateBtn").click(function(){
if(positions.length==0){
$(".remind").html('请先查询轨迹');
return;
}
if (animating) {
stopAnimation(false);
} else {
animating = true;
now = new Date().getTime();
speed = $("#speed").val();//速度
$("#animateBtn").html(' 取消回放');
carFeature.setStyle(null);
// map.getView().setCenter(center);
map.on('postcompose', moveFeature);
map.render();
}
});
var moveFeature = function(event) {
var vectorContext = event.vectorContext;
var frameState = event.frameState;
if (animating) {
var elapsedTime = frameState.time - now;
// here the trick to increase speed is to jump some indexes
// on lineString coordinates
var index = Math.round(speed * elapsedTime / 1000);
if (index >= positions.length) {
stopAnimation(true);
return;
}
var currentPoint = new ol.geom.Point(positions[index]);
var feature = new ol.Feature(currentPoint);
vectorContext.drawFeature(feature, carStyle);
}
// tell OL3 to continue the postcompose animation
map.render();
};
function startAnimation() {
if (animating) {
stopAnimation(false);
} else {
animating = true;
now = new Date().getTime();
speed = speedInput.value;
$("#animateBtn").html(' 取消回放');
// hide geoMarker
geoMarker.setStyle(null);
// just in case you pan somewhere else
map.getView().setCenter(center);
map.on('postcompose', moveFeature);
map.render();
}
}
function stopAnimation(ended) {
animating = false;
$("#animateBtn").html(' 轨迹回放');
// if animation cancelled set the marker at the beginning
var coord = ended ? positions[positions.length - 1] : positions[0];
/** @type {ol.geom.Point} */ (carFeature.getGeometry())
.setCoordinates(coord);
//remove listener
map.un('postcompose', moveFeature);
}
//轨迹回放end
解决linestring坐标显示不全
期间碰到一个问题
var lineFeature = new ol.Feature({//路线
geometry: new ol.geom.LineString(positions,'XY'),
});
linelayers.getSource().addFeature(lineFeature);
调用这段代码显示轨迹时，从数据库取到20个坐标，就可能只显示4个坐标，本来是弯曲的轨迹，但是实际上就是折线，很尴尬。
误打误撞，和同学 交流过程中发现问题所在，特此感谢。
在ajax获取坐标数据中发现问题所在：
原先错误代码
原先错误代码
position = [data[i].lon,data[i].lat];
positions.push(position);
正确代码
position = [parseFloat(data[i].lon),parseFloat(data[i].lat)];
positions.push(position);
原因就是没有把float类型的坐标利用parseFloat强转，导致默认的泛数据类型精确度不够，经纬度小数点后末尾几位就会被忽略，于是
造成数据失效，描出的线就会有问题。
附上附上icon、起点、终点、车辆等地图样式
、起点、终点、车辆等地图样式
//样式，供上述代码调用
var iconStyle = new ol.style.Style({
image: new ol.style.Icon(/** @type {olx.style.IconOptions} */ ({
anchor: [0.5, 0.8],
anchorXUnits: 'fraction',
anchorYUnits: 'pixels',
opacity: 0.75,
src: 'img/iconfont-weizhi-red.png'
}))
});
var startStyle = new ol.style.Style({
image: new ol.style.Icon(/** @type {olx.style.IconOptions} */ ({
anchor: [0.5, 0.8],
opacity: 0.8,
src: 'img/start.png'
/*anchorXUnits: 'fraction',
anchorYUnits: 'pixels',
opacity: 0.75,*/
}))
});
var endStyle = new ol.style.Style({
image: new ol.style.Icon(/** @type {olx.style.IconOptions} */ ({
src: 'img/end.png',
anchor: [0.5, 0.8],
}))
});
var carStyle = new ol.style.Style({
image: new ol.style.Icon(/** @type {olx.style.IconOptions} */ ({
src: 'img/car.png',
anchor: [0.5, 0.8],
}))
});
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