Sharing examples of using Baidu Maps to implement map grids-JS Tutorial-php.cn

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Sharing examples of using Baidu Maps to implement map grids

小云云

Feb 06, 2018 pm 03:24 PM

mapaccomplishBaidu

Recently, Baidu Map is used to realize the function of real estate visualization, so the most basic function is to grid the map to realize the division of real estate in different regions; this article mainly shares an example of using Baidu Map to realize the map grid. It has a very good reference value and I hope it will be helpful to everyone. Let’s follow the editor to take a look, I hope it can help everyone.

1. Go to the open platform of Baidu Maps to apply for a secret key. Here I will post your secret key; ak=A3CklGvnFOjkAzKzay2dySgfdig0GKz4

2. Create a new simple page , below I will post my own page

<!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, which introduces ziroom-map.js, which is the name of our company, I will post the code, This js encapsulates Baidu's js api. If anyone wants to ask why it is encapsulated, can't it be used directly? Then my answer is: Encapsulation can combine specific businesses and maps to make the code clearer, and can persist the current map state, which is beneficial to the operation of the map.

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: &#39;googlelite&#39;});
  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 = &#39;&#39; + 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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