Question

我无法在我的问题上找到正确的答案我需要帮助我尝试从mysql制作动态标记并在地图上显示它当前我从数据库中使用了latIn。我将数据从mysql传递给函数initMap参数并尝试循环它，以便它在地图上动态显示标记。

<script async defer src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCysW8SYjBdZlZa91kpUCV3VQBEm3EQGgE&callback=initMap" type="text/javascript"></script>

$.ajax({
             url: "Gmap.aspx/GetLocationLatIn",
             data: "",
             dataType: "json",
             type: "POST",
             contentType: "application/json; chartset=utf-8",
             success: function (data) {
                 locationLatIn = JSON.parse(JSON.stringify(data.d));
                 var holder = [];
                 var allLocations = "";
                 for (var i = 0; i < $(locationLatIn).toArray().length; i++) 
                 {
                 holder.push(locationLatIn[i].locationLatInData.toString());
                 }
                 initMap(holder);
             }
         });

     })
     function initMap(holder) {

         var map = new google.maps.Map(document.getElementById('map'), {
             zoom: 13,
             center: new google.maps.LatLng(14.6362904, 121.027754),
             mapTypeId: google.maps.MapTypeId.ROADMAP
         });

         var infowindow = new google.maps.InfoWindow();

         var marker, i;
         for (i = 0; i < holder.length; i++) { //Im getting an Error here saying that holder is undefined so the property length cant be read.
             marker = new google.maps.Marker({
                 position: new google.maps.LatLng(holder, 121.027754),
                 map: map
             });

             google.maps.event.addListener(marker, 'hover', (function 
             (marker, i) {
                 return function () {
                     infowindow.setContent('Name');
                     infowindow.open(map, marker);
                 }
             })(marker, i));
         }

Answer 1

$(locationLatIn).toArray().length - 此时可能你会收到错误。在控制台中检查$(locationLatIn)

的值

另外，为什么要对data.id进行stringyfying和解析。

它会返回元素标记或元素ID等。您尝试访问的内容是什么。

JS - 未捕获的TypeError：无法读取未定义的属性“长度”

1 个答案: