我的FBSingleClusterView
中有一个名为companyString
的字符串。但是我似乎无法访问,因为MKAnnotationView
不会更改为我的FBSingleClusterView
吗?
我的代码
func mapView(mapView: MKMapView, viewForAnnotation annotation: MKAnnotation) -> MKAnnotationView? {
var pinView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId)
pinView = FBSingleClusterView(annotation: annotation, reuseIdentifier: reuseId) as FBSingleClusterView
pinView.companyString = singleAnnotation.name
}
但是,我不断收到以下错误
value of type MKAnnotationView has no member companyString
。为什么不将其转换为MKAnnotationView的子类
FBSingleClusterView
呢?FBSingleClusterView
class FBSingleClusterView: MKAnnotationView {
var bubbleView: BubbleView?
var addressString: String?
var companyString: String?
var logoImage: UIImage?
override init(annotation: MKAnnotation?, reuseIdentifier: String?){
super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
// change the size of the cluster image based on number of stories
backgroundColor = UIColor.clearColor()
setNeedsLayout()
}
required override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override func layoutSubviews() {
// Images are faster than using drawRect:
centerOffset = CGPointMake(0, -image!.size.height/2);
}
}
最佳答案
您的第一行是
var pinView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId)
这样,pinView现在是MKAnnotationView类型吗?
Why come it isn't being casted into a FBSingleClusterView, which is a subclass of the MKAnnotationView?
设置var类型后,您将无法重新分配其他类型。
建议的解决方案是
if let pinView:FBSingleClusterView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId) as? FBSingleClusterView
{
pinView.companyString = singleAnnotation.name
}
关于ios - 无法在MKAnnotationView上转换子类,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/33341591/