iphone - 设置 Assetlibrary.framwork 时出错

Question

这是我的大问题。添加“Assetlibrary.Framwork”时，我的 mapView 运行时出现错误。如果我删除库，我的 mapView 就可以了。为什么？这是我的地图视图代码：（ps我正在使用情节提要）

.h
@property (strong, nonatomic) IBOutlet MKMapView *MapView;

.m
viewdidload:
MapView.delegate = self;
[self setLocationManager:[[CLLocationManager alloc] init]];
[locationManager setDelegate:self];
[locationManager setDistanceFilter:kCLDistanceFilterNone];
[locationManager setDesiredAccuracy:kCLLocationAccuracyHundredMeters];
[locationManager startUpdatingLocation];

- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
if ((oldLocation.coordinate.longitude != newLocation.coordinate.longitude)
    || (oldLocation.coordinate.latitude != newLocation.coordinate.latitude)) {

    coord.latitude = newLocation.coordinate.latitude;
    coord.longitude = newLocation.coordinate.longitude;


    region.center = coord;

    span.latitudeDelta = 0.05;
    span.longitudeDelta = 0.05;
    region.span = span;
}

这是我的错误：

'NSUnknownKeyException'，原因：'[setValue:forUndefinedKey:]：此类不符合键 MapView 的键值编码。

我是否设置了两次地图视图？还是我做错了什么？