地图标记在Google地图中未显示？

Question

地图工作正常，但当我尝试添加标记它不起作用？

这里是我到目前为止的代码：

<script src="http://maps.googleapis.com/maps/api/js?key=AIzaSyDY0kkJiTPVd2U7aTOAwhc9ySH6oHxOIYM&sensor=false"></script> 

<script> 
    function initialize() 
    {var mapProp = { 

center: new google.maps.LatLng(-33.975618,25.585858), 
zoom:15, 
panControl:true, 
zoomControl:true, 
mapTypeControl:true, 
scaleControl:true, 
streetViewControl:true, 
overviewMapControl:true, 
rotateControl:true,  
mapTypeId: google.maps.MapTypeId.ROADMAP 
}; 
var map = new google.maps.Map(document.getElementById("column2linksmap2"),mapProp); 

var marker = new google.maps.Marker({ 
    position: latLng, 
    title:"Hello World!", 
    visible: true 
}); 
    marker.setMap(map); 


} 
    google.maps.event.addDomListener(window, 'load', initialize); 

</script> 

Answer 1

- var marker = new google.maps.Marker({ 
    position: (Give lat & long 
    here), title:"Hello World!", visible: true }); 
    marker.setMap(map); 

你可能会丢失给予的latLng

Answer 2

position: latLng 

你是什么地方申报的latLng？

Answer 3

function initialize() { 
    var Latlng = new google.maps.LatLng(-25.363882,131.044922); 

    var mapOptions = { 
     zoom: 4, 
     center: myLatlng 
    } 

    var map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions); 

    var marker = new google.maps.Marker({ 
    position: Latlng, 
     map: map, 
     title: 'Hello World!' 
    }); 
} 

google.maps.event.addDomListener(window, 'load', initialize); 

的问题是，你还没有宣布经纬度