我怎样才能在Android中的谷歌地图V2可见的标记？ [英] How can I get the visible markers in Google Maps v2 in Android?

问题描述

在谷歌地图V2为Android，我怎么能得到明显的标志？我知道我可以使用投影和消除点＆LT; 0和要点>的屏幕尺寸。但我不希望由一个二选一，也可以是太慢了，如果我有很多标记。有没有简单的方法？或者一些现成的，现成的解决方案？如果有，是哪一个？

In Google Maps v2 for Android, how can I get the visible markers? I know I can use Projection and eliminate points < 0 and points > screen size. But I do not wish to check one by one, it can be too slow if I have a lot of markers. Is there any easy way? Or some off-the-shelf solution? If yes, which one?

推荐答案

好吧，下面是code之前，我已经使用，以确定哪些用户可以看到，然后只绘制可见的标记。
我想你也许能使其适应你的目的。

Ok, the following is the code the I have used before to determine what the user can see and then only draw the markers that are visible. I think you might be able to adapt it to your purpose.

获取地图的当前矩形视窗（注：必须在主线程上运行）

get the current rectangle "viewport" of the map (note:must be run on the main thread)

    this.mLatLngBounds = this.mMap.getProjection().getVisibleRegion().latLngBounds;

2点（左上和右下）进行排序，以便我们可以使用最小/最大逻辑

sort the 2 points (top-left and bottom-right) so that we can use min/max logic

double lowLat;
double lowLng;
double highLat;
double highLng;

if (this.mLatLngBounds.northeast.latitude < this.mLatLngBounds.southwest.latitude)
{
lowLat = this.mLatLngBounds.northeast.latitude;
highLat = this.mLatLngBounds.southwest.latitude;
}
else
{
highLat = this.mLatLngBounds.northeast.latitude;
lowLat = this.mLatLngBounds.southwest.latitude;
}
if (this.mLatLngBounds.northeast.longitude < this.mLatLngBounds.southwest.longitude)
{
lowLng = this.mLatLngBounds.northeast.longitude;
highLng = this.mLatLngBounds.southwest.longitude;
}
else
{
highLng = this.mLatLngBounds.northeast.longitude;
lowLng = this.mLatLngBounds.southwest.longitude;
}

然后在我的情况，我在一个数据库这个数据，所以我可以使用> =和＆lt; =只提取我想要的销

then in my case I had this data in a db, so i could use >= and <= to extract only the pins i wanted

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