Question

我正在尝试引用我创建的标记数组但是当我尝试引用数组元素时，元素接收消息GLOBAL_MARK.0为null或不是对象。我认为这可能是一个范围问题，但我不知道如何处理它。这是代码。

var GLOBAL_MARK = "[]"
var vcount = 0;

 function load() {

   if (GBrowserIsCompatible()) {       
   var map = new GMap2(document.getElementById("map"));         
   map.addControl(new GSmallMapControl());         
   map.addControl(new GMapTypeControl());       
   MyLat = "47.614495"
   MyLng =  "-122.341861"
                                                                            map.setCenter(new GLatLng(MyLat, MyLng), 13); 

    GDownloadUrl("allmarkers.php", function(data) {        
    var xml = GXml.parse(data);          
    var markers = xml.documentElement.getElementsByTagName("marker");          
    for (var i = 0; i < markers.length; i++) {      
        var name = markers[i].getAttribute("name"); 
        var id = markers[i].getAttribute("id");   
        var address = markers[i].getAttribute("address");             
        var type = markers[i].getAttribute("type");            
        var point = new GLatLng(parseFloat(markers[i].getAttribute("lat")), parseFloat(markers [i].getAttribute("lng")));             

        var marker = createMarker(point, name, address, type, id);    
        MyAddMarker(marker)
        map.addOverlay(marker);          
     }        
});   
OutTest()    
}    
}      

function MyAddMarker(marker) {
    GLOBAL_MARK[vcount] = marker
    vcount = vcount + 1
}

function OutTest() {
    alert(GLOBAL_MARK[0].getLatLng)
}


function createMarker(point, name, address, type, id, date1, date2) {      
var marker = new GMarker(point, customIcons[type]);    
var html = "<b>" + name + "</b> <br/>" + address + "<br><br><input type=\"button\"    value=\"  View Posts  \" onclick=\"view_posts('" + id + "','" + type + "','" + date1 + "','" + date2 + "','no')\">"
 GEvent.addListener(marker, 'click', function() {         
 marker.openInfoWindowHtml(html);
  }); 
   return marker;    
    }

Answer 1

此代码中有很多错误。 GLOBAL_MARK肯定被宣称错误，被用作MyAddMarker()中使用它的对象。我会尝试尽可能多地修复，但实际上无法运行代码：

GLOBAL_MARK = [];
GDownloadUrl("allmarkers.php", function(data) {        
    var xml = GXml.parse(data);          
    var markers = xml.documentElement.getElementsByTagName("marker");          
    for (var i = 0; i < markers.length; i++) {      
        var name = markers[i].getAttribute("name"); 
        var id = markers[i].getAttribute("id");   
        var address = markers[i].getAttribute("address");             
        var type = markers[i].getAttribute("type");            
        var point = new GLatLng(
            parseFloat(markers[i].getAttribute("lat")), 
            parseFloat(markers[i].getAttribute("lng"))
        );
        var marker = createMarker(point, name, address, type, id);    
        MyAddMarker(marker);
        map.addOverlay(marker);          
     }
// when the code gets here, the data from allmarkers.php is done
});

OutTest();

function MyAddMarker(marker) {
    GLOBAL_MARK[vcount] = marker;
    vcount = vcount + 1;
}

function OutTest() {
    alert(GLOBAL_MARK[0].getLatLng);
}

另外，我没有在任何地方看到vcount的声明。

而且，我怀疑你在OutTest()中的匿名函数完成之前正在调用GDownloadUrl。当你调用OutTest()时，这很可能是一个尚未完成的异步函数。

引用一组Google Map标记

1 个答案: