Google地图V3：检查地图上是否存在标记？ [英] Google Maps V3: Check if marker is present on map?

问题描述

在Google Maps V3中，有没有方法可以检查地图上是否存在标记？

我点击标记时会消失。我想要一些逻辑来检查标记的当前可见性。

例如：

  var start_marker = null; 
 start_marker = new google.maps.Marker（{position：location，map：map，clickable：true}）; 
 google.maps.event.addListener（start_marker，'click'，function（event）{
 start_marker.setMap（null）; 
}）; 
 // ...稍后在代码中：检查标记当前是否可见。 
 console.log（'start_marker的类型现在是：'+ typeof（start_marker））; 
  

我希望当标记不可见时这会给我一个null类型，但事实上它仍然是一个对象。

那么，我该如何检查这个特定的标记是否可以在地图上看到？

谢谢！ / p>

解决方案

如果在当前 map 边界下，c> marker 的位置是 contains ，并返回 false 如果不是。

  map.getBounds（）。contains（marker.getPosition（））
  

希望有帮助，干杯！

In Google Maps V3, is there a way to check whether a marker is actually present on the map?

I have markers that vanish when clicked. I'd like some logic to check the present visibility of the marker.

For example:

var start_marker = null;
start_marker = new google.maps.Marker({ position: location, map: map, clickable: true });
google.maps.event.addListener(start_marker, 'click', function(event) {
  start_marker.setMap(null);
}); 
// ... Later in code: check whether marker is currently visible. 
console.log('Type of start_marker is now: ' + typeof(start_marker));

I was hoping this would give me a null type when the marker isn't visible, but in fact it's still an Object.

So, how else can I check whether this particular marker is visible on the map?

Thanks!

解决方案

This one-liner will return true if the marker's position is contained under the current map boundary, and return false if not.

map.getBounds().contains(marker.getPosition())

Hope that helps, Cheers!

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