Google Maps Api v3 - getBounds未定义(Google Maps Api v3 - getBounds is undefined)

 我从v2切换到v3 google maps api，并遇到gMap.getBounds()函数的问题。 
 
 我需要在初始化之后获取我的地图的边界。 
 
 这是我的JavaScript代码： 
 

var gMap;
$(document).ready(

    function() {

        var latlng = new google.maps.LatLng(55.755327, 37.622166);
        var myOptions = {
            zoom: 12,
            center: latlng,
            mapTypeId: google.maps.MapTypeId.ROADMAP
        };
        gMap = new google.maps.Map(document.getElementById("GoogleMapControl"), myOptions);

        alert(gMap.getBounds());
    }
);
 
 所以现在它提醒我， gMap.getBounds()是未定义的。 
 
 我试图在点击事件中获取getBounds值，它对我来说可以正常工作，但是我无法在load map事件中获得相同的结果。 
 
 在Google Maps API v2中加载文档时，getBounds也可以正常工作，但在V3中失败。 
 
 你能帮我解决这个问题吗？ 

I'm switching from v2 to v3 google maps api and got a problem with gMap.getBounds() function.
 
I need to get the bounds of my map after its initialization.
 
Here is my javascript code:
 

var gMap;
$(document).ready(

    function() {

        var latlng = new google.maps.LatLng(55.755327, 37.622166);
        var myOptions = {
            zoom: 12,
            center: latlng,
            mapTypeId: google.maps.MapTypeId.ROADMAP
        };
        gMap = new google.maps.Map(document.getElementById("GoogleMapControl"), myOptions);

        alert(gMap.getBounds());
    }
);
 
So now it alerts me that gMap.getBounds() is undefined. 
 
I've tried to get getBounds values in click event and it works fine for me, but I cannot get the same results in load map event.
 
Also getBounds works fine while document is loading in Google Maps API v2, but it fails in V3.
 
Could you please help me to solve this problem?

原文：https://stackoverflow.com/questions/2832636