地图网格的实现

时间：2020-11-27 来源：乌哈旅游

这次给大家带来地图网格的实现，地图网格实现的注意事项有哪些，下面就是实战案例，一起来看一下。

前言：最近要使用百度地图实现楼盘可视化的功能，因此最基础的功能就是将地图网格化以后实现不同地域的楼盘划分；

1，自行去百度地图的开放平台申请秘钥哈，这里我就把自己的秘钥贴出来了；ak=A3CklGvnFOjkAzKzay2dySgfdig0GKz4

2，新建一个简单页面，下面我把自己的页面贴出来

<!DOCTYPE html>
<html>
<head>
 <meta name="viewport" content="initial-scale=1.0, user-scalable=no"/>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
 <style type="text/css">
 html {
 height: 100%
 }
 body {
 height: 100%;
 margin: 0px;
 padding: 0px
 }
 #container {
 height: 100%
 }
 </style>
 <script type="text/javascript" src="http://api.map.baidu.com/api?v=2.0&ak=A3CklGvnFOjkAzKzay2dySgfdig0GKz4"></script> 
<script type="text/javascript" src="ziroom-map.js"></script>
 </head>
 <body> 
<p id="container"></p>
 <script> 
var myMap = new ZMap("container"); </script>
 </body>
 </html>

3,其中引入了ziroom-map.js，这是我们公司的名字啦，我把代码贴出来，这个js是封装了百度的js的api的，有人如果要问为什么封装，直接使用不可以么？那我的回答是：封装可以将具体业务和地图相结合，使代码更清晰，并且可以持久化当前地图的状态，利于实现对地图的操作。

var ZMap = function (id, center, level) {
 this.initCenter = new ZPoint(116.404, 39.915);//初始化的中心点，同时为了定义网格的中心点
 this.id = id;//p的id
 this.level = level ? level : 13;//地图级别
 this.center = center ? center : this.initCenter;//中心点
 this.map = null;//百度地图实例
 this.xgrids = [];//经线
 this.ygrids = [];//纬线
 this.beSelectBounds = {};
 this.bounds = null;//当前地图的四个顶点
 this.span = null;//当前网格的跨度
 this.init();
}
ZMap.prototype = {
 init: function () {//全局初始化
 var zMap = this;
 this.map = new BMap.Map(this.id);
 this.map.centerAndZoom(this.center.point, this.level);
 this.map.enableScrollWheelZoom();
 this.map.disableInertialDragging();
 this.map.addControl(new BMap.NavigationControl({
 anchor: BMAP_ANCHOR_BOTTOM_RIGHT,
 type: BMAP_NAVIGATION_CONTROL_ZOOM
 })); //缩放按钮
 this.map.addControl(new BMap.ScaleControl({anchor: BMAP_ANCHOR_BOTTOM_LEFT, offset: new BMap.Size(80, 25)})); //比例尺
 this.map.disableDoubleClickZoom();
 this.map.setMapStyle({style: 'googlelite'});
 this.initProperty();
 this.initGrid();
 //添加移动后的点击事件
 this.map.addEventListener("dragend", function () {
 zMap.initProperty();
 zMap.initGrid();
 });
 //添加放大或缩小时的事件
 this.map.addEventListener("zoomend", function () {
 zMap.initProperty();
 zMap.initGrid();
 });
 //设置点击事件
 this.map.addEventListener("click", function (e) {
 var point = e.point;
 //获取当前点是在哪个区块内,获取正方形的四个顶点
 var points = zMap.getGrid(point);
 //判断当前区域是否已经被选中过，如果被选中过则取消选中
 var key = '' + points[0].lng + points[0].lat + points[2].lng + points[2].lat;//使用两个点的坐标作为key
 if (zMap.beSelectBounds[key]) {
 zMap.map.removeOverlay(zMap.beSelectBounds[key]);
 delete zMap.beSelectBounds[key];
 return;
 }
 var polygon = new BMap.Polygon(points, {strokeColor: "red", strokeWeight: 2, strokeOpacity: 0.5});
 zMap.map.addOverlay(polygon);
 zMap.beSelectBounds[key] = polygon;
 });
 },
 initProperty: function () {//初始化当前地图的状态
 this.level = this.map.getZoom();
 this.bounds = {
 x1: this.map.getBounds().getSouthWest().lng,
 y1: this.map.getBounds().getSouthWest().lat,
 x2: this.map.getBounds().getNorthEast().lng,
 y2: this.map.getBounds().getNorthEast().lat
 };
 this.span = this.getSpan();//需要使用level属性
 },
 initGrid: function () {//初始化网格
 var zMap = this;
 //将原来的网格线先去掉
 for (var i in zMap.xgrids) {
 this.map.removeOverlay(zMap.xgrids[i]);
 }
 zMap.xgrids = [];
 for (var i in zMap.ygrids) {
 this.map.removeOverlay(zMap.ygrids[i]);
 }
 zMap.ygrids = [];
 //获取当前网格跨度
 var span = zMap.span;
 //初始化地图上的网格
 for (var i = zMap.bounds.x1 + (zMap.initCenter.point.lng - zMap.bounds.x1) % span.x - span.x; i < zMap.bounds.x2 + span.x; i += span.x) {
 var polyline = new BMap.Polyline([
 new BMap.Point(i.toFixed(6), zMap.bounds.y1),
 new BMap.Point(i.toFixed(6), zMap.bounds.y2)
 ], {strokeColor: "black", strokeWeight: 1, strokeOpacity: 0.5});
 zMap.xgrids.push(polyline);
 zMap.map.addOverlay(polyline);
 }
 for (var i = zMap.bounds.y1 + (zMap.initCenter.point.lat - zMap.bounds.y1) % span.y - span.y; i < zMap.bounds.y2 + span.y; i += span.y) {
 var polyline = new BMap.Polyline([
 new BMap.Point(zMap.bounds.x1, i.toFixed(6)),
 new BMap.Point(zMap.bounds.x2, i.toFixed(6))
 ], {strokeColor: "black", strokeWeight: 1, strokeOpacity: 0.5});
 zMap.ygrids.push(polyline);
 zMap.map.addOverlay(polyline);
 }
 },
 getSpan: function () {//获取网格的跨度
 var scale = 0.75;
 var x = 0.00064;
 for (var i = this.level; i < 19; i++) {
 x *= 2;
 }
 var y = parseFloat((scale * x).toFixed(5));
 return {x: x, y: y};
 },
 getGrid: function (point) {//返回当前点在所在区块的四个顶点
 var zMap = this;
 //先找出两条纵线坐标
 var xpoints = this.xgrids.map(function (polyline) {
 return polyline.getPath()[0].lng;
 }).filter(function (lng) {
 return Math.abs(lng - point.lng) <= zMap.span.x;
 }).sort(function (a, b) {
 return a - b;
 }).slice(0, 2);
 //再找出两条横线的坐标
 var ypoints = this.ygrids.map(function (polyline) {
 return polyline.getPath()[0].lat;
 }).filter(function (lat) {
 return Math.abs(lat - point.lat) <= zMap.span.y;
 }).sort(function (a, b) {
 return a - b;
 }).slice(0, 2);
 return [
 new BMap.Point(xpoints[0], ypoints[0]),
 new BMap.Point(xpoints[0], ypoints[1]),
 new BMap.Point(xpoints[1], ypoints[1]),
 new BMap.Point(xpoints[1], ypoints[0])
 ];
 },
 reset: function () {//重置
 this.map.reset();
 }
}
var ZPoint = function (x, y, code) {
 this.code = code;
 this.point = new BMap.Point(x, y);
}

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