ClLocationCoordinate2D的NSMutableArray [英] NSMutableArray of ClLocationCoordinate2D
问题描述
我正在尝试创建然后检索CLLocationCoordinate2D对象的数组,但由于某种原因,该数组始终为空。
I'm trying to create then retrieve an array of CLLocationCoordinate2D objects, but for some reason the array is always empty.
我有:
NSMutableArray *currentlyDisplayedTowers;
CLLocationCoordinate2D new_coordinate = { currentTowerLocation.latitude, currentTowerLocation.longitude };
[currentlyDisplayedTowers addObject:[NSData dataWithBytes:&new_coordinate length:sizeof(new_coordinate)] ];
我也试过这个来添加数据:
I've also tried this for adding the data:
[currentlyDisplayedTowers addObject:[NSValue value:&new_coordinate withObjCType:@encode(struct CLLocationCoordinate2D)] ];
无论哪种方式,[currentDisplayedTowers count]总是返回零。什么想法可能会出错?
And either way, the [currentlyDisplayedTowers count] always returns zero. Any ideas what might be going wrong?
谢谢!
推荐答案
要留在对象土地上,你可以创建 CLLocation的实例
并将它们添加到可变数组中。
To stay in object land, you could create instances of CLLocation
and add those to the mutable array.
CLLocation *towerLocation = [[CLLocation alloc] initWithLatitude:lat longitude:lon];
[currentDisplayedTowers addObject:towerLocation];
从<获取 CLLocationCoordinate
结构code> CLLocation ,在对象上调用坐标
。
To get the CLLocationCoordinate
struct back from CLLocation
, call coordinate
on the object.
CLLocationCoordinate2D coord = [[currentDisplayedTowers lastObject] coordinate];
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