1.代码
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>OpenLayers</title>
<link rel="stylesheet" href="geoserver/ol.css" type="text/css">
<script src="geoserver/ol.js"></script>
<script src="bower_components/jquery/dist/jquery.min.js"></script>
<link rel="stylesheet" href="plugins/layui-v2.4.3/layui/css/layui.css">
<script src="plugins/layui-v2.4.3/layui/layui.js" charset="utf-8"></script>
<link rel="stylesheet" href="https://openlayers.org/en/v3.20.1/css/ol.css" type="text/css">
<#--注意openlayer的版本号，高版本存在es6中新语法不兼容的情况-->
<script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"></script>
<script src="https://openlayers.org/en/v3.20.1/build/ol.js"></script>
</head>
<style>
#map {
height: 600px;
/*width: 1024px;*/
/* float: left;*/
}
</style>
<body>
<div id="map">
<form class="form-inline">
<label>查询类型</label>
<select id="type">
<option value="None">None</option>
<option value="Point">点击</option>
<option value="Polygon">多边形</option>
<option value="Circle">拉框</option>
</select>
</form>
</div>
<script>
var map = new ol.Map({
target: 'map',
view: new ol.View({
projection: 'EPSG:4326',
center: [104.07, 30.72],
zoom: 7
})
});
var wfsParams = {
service: 'WFS',
version: '1.1.1',
request: 'GetFeature',
typeName: 'map_dz:tl_lx_g', //图层名称，可以是单个或多个
outputFormat: 'text/javascript', //重点，不要改变
format_options: 'callback:loadFeatures' //回调函数声明
}; var vectorSource = new ol.source.Vector({
format: new ol.format.GeoJSON(),
loader: function (extent, resolution, projection) { //加载函数
var url = 'http://192.168.1.113:8080/geoserver/map_dz/wms';
$.ajax({
url: url,
data: $.param(wfsParams), //传参
type: 'GET',
dataType: 'jsonp', //解决跨域的关键
jsonpCallback: 'loadFeatures' //回调 });
},
strategy: ol.loadingstrategy.tile(new ol.tilegrid.createXYZ({
maxZoom: 20
})),
projection: 'EPSG:4326'
});
//回调函数使用
window.loadFeatures = function (response) {
vectorSource.addFeatures((new ol.format.GeoJSON()).readFeatures(response)); //载入要素
};
var vectorLayer = new ol.layer.Vector({
source: vectorSource,
style: new ol.style.Style({
stroke: new ol.style.Stroke({
color: 'rgba(0, 0, 255, 1.0)',
width: 2
})
})
});
map.addLayer(vectorLayer);
var draw;
var typeSelect = document.getElementById('type');
var value;
var num=10;//用于删除之前的框，表示号，随便取一个
function addInteraction() {
if (value !== 'None') {
if (value === 'Polygon') {
draw = new ol.interaction.Draw({
source: vectorLayer.getSource(),
style: new ol.style.Style({
stroke: new ol.style.Stroke({
color: '#ffcc33',
width: 2
}),
image: new ol.style.Circle({
radius: 7,
fill: new ol.style.Fill({
color: '#ffcc33'
})
})
}),
type: value
});
} else if (value === 'Circle') {
draw = new ol.interaction.Draw({
source: vectorLayer.getSource(),
style: new ol.style.Style({
stroke: new ol.style.Stroke({
color: '#ffcc33',
width: 2
}),
image: new ol.style.Circle({
radius: 7,
fill: new ol.style.Fill({
color: '#ffcc33'
})
})
}),
type: value,
geometryFunction: ol.interaction.Draw.createBox()
});
} else if (value === 'Point') {
draw = new ol.interaction.Draw({
source: vectorLayer.getSource(),
style: new ol.style.Style({
stroke: new ol.style.Stroke({
color: '#ffcc33',
width: 2
}),
image: new ol.style.Circle({
radius: 7,
fill: new ol.style.Fill({
color: '#ffcc33'
})
})
}),
type: value
});
} map.addInteraction(draw);
//删除之前draw的部分
draw.on('drawstart',function(evt) {
var featureAdd=vectorLayer.getSource().getFeatureById(num);
if(featureAdd!=null){
vectorLayer.getSource().removeFeature(featureAdd);
}
});
//绘图结束，处理选中部分
draw.on('drawend',function(e){
e.feature.setId(num);
var geom=e.feature.getGeometry();
var coor = geom.v;
mapSelect(coor);
});
}
}
//选择事件
typeSelect.onchange = function() {
value = typeSelect.value;
map.removeInteraction(draw);
addInteraction();
}; //draw图像与原始数据相交
function mapSelect(coor) {
if(value=='Point') {
coor = [coor[0]-0.0001,coor[1]-0.0001,coor[0]+0.0001,coor[1]+0.0001];
}
var FILTER = '<Filter xmlns:ogc="http://www.opengis.net/ogc" xmlns:gml="http://www.opengis.net/gml"><BBOX><PropertyName>geom</PropertyName><gml:Envelope srsName="EPSG:4326"><gml:lowerCorner>' + coor[0] + ' ' + coor[1] + '</gml:lowerCorner><gml:upperCorner>' + coor[2] + ' ' + coor[3] + '</gml:upperCorner></gml:Envelope></BBOX></Filter>';
getFeature({
typename: 'map_dz:tl_lx_g',//查询的服务图层名称
filter: FILTER,//查询条件
callback: 'getIdentifyroadGrid'//查询的回调函数
});
}
var selectNum=[];
var geojsonFormat = new ol.format.GeoJSON({defaultDataProjection: "EPSG:4326"});
function getIdentifyroadGrid(res) {
var queryData = [];
var features = geojsonFormat.readFeatures(res); for (var nu = 0; nu<selectNum.length;nu++) {
var featureSelect=vectorLayer.getSource().getFeatureById(selectNum[nu]);
if(featureSelect!=null) {
featureSelect.setStyle(
new ol.style.Style({
stroke: new ol.style.Stroke({
color: 'rgba(0, 0, 255, 1.0)',
width: 2
})
}));
}
}
selectNum=[];
for (var i = 0; i < features.length; i++) {
var feature = features[i];
console.log(feature);
selectNum.push(feature.f);
var featureSelectCurrent=vectorLayer.getSource().getFeatureById(feature.f);
featureSelectCurrent.setStyle(
new ol.style.Style({
stroke: new ol.style.Stroke({
color: '#ff4118',
width: 2
})
}));
var lxmc = feature.H["lxmc"];
var ldbm = feature.H["ldbm"];
var lxbh = feature.H["lxbh"];
var result = {
"lxmc": lxmc,
"ldbm": ldbm,
"lxbh": lxbh,
"setindex": i
};
queryData.push(result)
}
console.log(selectNum);
var tableIns=null;
var dataTable = "<table class=\"layui-table\" lay-filter=\"demo\" id=\"joinTab\"></table>";
layui.use(['table', 'layer'], function () {
var table = layui.table;
var layer = layui.layer;
var index = layer.open({
type: 1 //Page层类型
, title: '要素属性'
, shade: 0 //遮罩透明度
, anim: 0 //0-6的动画形式，-1不开启
, content: dataTable
, offset: ['250px', '290px']
, zIndex: 1
, scrollbar: false
, resize: false
, skin: 'layui-layer-molv'
, closeBtn: 2
, btn: ["关闭"]
, yes: function (index) {
layer.close(index);
}
, cancel: function () {
}
});
tableIns = table.render({
elem: "#joinTab",
width: "auto",
height: "auto",
data: queryData,
initSort: {field: 'lxbh', type: 'desc'},
cols: [[
{field: 'lxmc', title: '路线名称', width: 150, align: 'center', sort: true},
{field: 'ldbm', title: '路线编号', width: 150, align: 'center', sort: true},
{field: 'lxbh', title: '路段编码', width: 150, align: 'center', sort: true}
]]
});
layer.style(index, {
opacity: 0.8
});
}); if (tableIns) {
tableIns.reload({
data: queryData
});
} else {
// console.log("Do Nothing!");
}
} //请求wfs数据
function getFeature(options) {
$.ajax(/*'http://192.168.1.113:8080/geoserver/map_dz/wms', */{
type: 'GET',
url: 'http://192.168.1.113:8080/geoserver/map_dz/wms',
data: {
service: 'WFS',
version: '1.1.1',
request: 'GetFeature',
typename: options.typename,
srsname: options.srid,
outputFormat: 'text/javascript',
viewparams: options.viewparams,
bbox: (options.extent === undefined) ? undefined : options.extent.join(',') + ',' + options.srid,
filter: options.filter
},
dataType: 'jsonp',
jsonp: 'format_options',
jsonpCallback: 'callback:' + options.callback
}); } </script>
</body>
</html>
2.代码解释
这一部分是主要针对用户做此功能的时候，遇到的问题进行总结：
在引入 Openlayers 的 JS 文件的时候，注意版本号，5.0+ 的版本中大量应用了ES6 的最新特性，如果直接引入 5.0+ ，可能与前期的项目有所冲突，所以这里建议使用低版本，同样能完成拉框查询
这里主要通过 Draw 对象进行框选的，Draw 的本质是在图层上兴建 Shape ，那么在下一次框选的时候，需要把上次 Draw 的框去掉：（回答了网上用户的提问：openlayers 在重新画图(圆或矩形)如何清除之前的图，Openlayer删除上一次绘制的图）
首先记录框选时，增加的框框的ID
然后在下次框选之前，通过 id 找到上次那个 Feature，并删掉
对选中的对象进行重新设置颜色，这里主要通过 Style 属性进行处理：
在下次选中对象的时候，删除上次选中对象的样式 将选中对象的 id 压到数组汇总
在下次设置选中对象的样式之前，遍历数组，对上次选中的feature进行样式设置（设置为原来的样式）
3.结果
参考
https://www.cnblogs.com/kkyyhh96/p/6379515.html
https://blog.csdn.net/songjian1314/article/details/17263865
https://blog.csdn.net/shaxiaozilove/article/details/60780175
https://blog.csdn.net/m0_37659871/article/details/80598589
https://openlayers.org/en/latest/examples/draw-features.html
https://openlayers.org/en/latest/examples/draw-shapes.html
