AMap行政区查询服务

AMap.DistrictSearch行政区查询服务插件，提供全国各省、市、县、区的中心点经纬度、行政区边界坐标组、下级行政区等信息。根据行政区边界坐标组可在地图上绘制行政区边界。（本文为原创，并在项目中验证成功。作者：张甫军）

第一步，插件及样式的引用：

    <link rel="stylesheet" href="http://cache.amap.com/lbs/static/main1119.css" />
    <script src="http://webapi.amap.com/maps?v=1.3&key=7defcebd378d7fcd05dbcb9298d20d2e&plugin=AMap.PolyEditor,AMap.CircleEditor,AMap.MouseTool,AMap.DistrictSearch"></script>
    <script type="text/javascript" src="http://cache.amap.com/lbs/static/addToolbar.js"></script>
 <script type="text/javascript" src="http://webapi.amap.com/demos/js/liteToolbar.js"></script>

第二步，HTML代码：

  <div id="container"></div>
    <div id="tip">
        省：<select id='province' style="100px" onchange='search(this)'></select>
        市：<select id='city' style="100px" onchange='search(this)'></select>
        区：<select id='district' style="100px" onchange='search(this)'></select>
        街道：<select id='street' style="100px" onchange='setCenter(this)'></select>
        &nbsp;&nbsp;<input type="button" id="clearMap" onclick="clearMap()" value="清除" />
    </div>

第三步，页面CSS样式：

    <style type="text/css">
        #tip {
            background-color: #fff;
            padding: 0 10px;
            border: 1px solid silver;
            box-shadow: 3px 4px 3px 0px silver;
            position: absolute;
            font-size: 12px;
            right: 10px;
            top: 5px;
            border-radius: 3px;
            line-height: 36px;
        }
    </style>

第四步，JavaScript代码：

初始化地图：

        var editorTool, district, polygons = [], citycode, map = new AMap.Map("container", {
            //resizeEnable: true,
            //center: [116.403322, 39.900255],
            //zoom: 13
            resizeEnable: true,
            //center: [116.30946, 39.937629],
            zoom: 3
        });

初始化搜索下拉框：

        var citySelect = document.getElementById('city');
        var districtSelect = document.getElementById('district');
        var areaSelect = document.getElementById('street');

        var opts = {
            subdistrict: 1,
            level: 'city',
            showbiz: false
        };
        district = new AMap.DistrictSearch(opts);
        district.search('中国', function (status, result) {
            if (status == 'complete') {
                getData(result.districtList[0]);
            }
        });
        var mapCenter = null;
        var districtObj = {
            Center: null,
            Bounds: null
        };
        function getData(data) {
            var bounds = data.boundaries;
            mapCenter = data.center;
            districtObj.Center = data.center;
            districtObj.Bounds = bounds == null ? districtObj.Bounds : bounds;
            console.log('default1');
            if (bounds && '@((int)ElectronicFenceModel.ShapeType.District)' == '@((int)shapeType)') {
                for (var i = 0, l = bounds.length; i < l; i++) {
                    var polygon = new AMap.Polygon({
                        map: map,
                        strokeWeight: 1,
                        strokeColor: '#CC66CC',
                        fillColor: '#CCF3FF',
                        fillOpacity: 0.5,
                        path: bounds[i]
                    });
                    polygons.push(polygon);
                }
                map.setFitView();
            }

            var subList = data.districtList;
            var level = data.level;

            if (level === 'province') {
                nextLevel = 'city';
                citySelect.innerHTML = '';
                districtSelect.innerHTML = '';
                areaSelect.innerHTML = '';
            } else if (level === 'city') {
                nextLevel = 'district';
                districtSelect.innerHTML = '';
                areaSelect.innerHTML = '';
            } else if (level === 'district') {
                nextLevel = 'street';
                areaSelect.innerHTML = '';
            }
            if (subList) {
                var contentSub = new Option('--请选择--');
                for (var i = 0, l = subList.length; i < l; i++) {
                    var name = subList[i].name;
                    var levelSub = subList[i].level;
                    var cityCode = subList[i].citycode;
                    if (i == 0) {
                        document.querySelector('#' + levelSub).add(contentSub);
                    }
                    contentSub = new Option(name);
                    contentSub.setAttribute("value", levelSub);
                    contentSub.center = subList[i].center;
                    contentSub.adcode = subList[i].adcode;
                    document.querySelector('#' + levelSub).add(contentSub);
                }
            }

        }
        function search(obj) {
            //清除地图上所有覆盖物
            for (var i = 0, l = polygons.length; i < l; i++) {
                polygons[i].setMap(null);
            }
            var option = obj[obj.options.selectedIndex];
            var keyword = option.text; //关键字
            var adcode = option.adcode;
            district.setLevel(option.value); //行政区级别
            district.setExtensions('all');
            //行政区查询
            //按照adcode进行查询可以保证数据返回的唯一性
            district.search(adcode, function (status, result) {
                if (status === 'complete') {
                    getData(result.districtList[0]);
                    setFence();
                }
            });
        }
        function setCenter(obj) {
            mapCenter = obj[obj.options.selectedIndex].center;
            map.setCenter(obj[obj.options.selectedIndex].center);
            setFence();
        }

        function clearMap() {
            map.clearMap();
        }

以上代码，可以完成行政区查询，提供全国各省、市、县、区的中心点经纬度、行政区边界坐标组、下级行政区等信息。根据行政区边界坐标组可在地图上绘制行政区边界。注意：AMap.DistrictSearch行政区查询服务插件的初始化有2种方式，第一种：使用插件同步下发功能才能这样直接使用（本文采用此种方式，注意查看插件的引用）；第二种：（查看下面的代码）

mapObj.plugin('AMap.DistrictSearch', function () {
					var opts = {
					subdistrict: 0, //返回下一级行政区
					extensions: 'all', //返回行政区边界坐标组等具体信息
					level:'city' //查询行政级别为 市
				};

mapObj.plugin('AMap.DistrictSearch', function () {

var opts = {

subdistrict: 0, //返回下一级行政区

extensions: 'all', //返回行政区边界坐标组等具体信息

level:'city'//查询行政级别为市

};