Question

我有很长的MKannotationView标题文字。是否有一种简单的方法可以使标题文本适当大小？

reuseId = "Pin"
        var pinView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId)
        pinView = MKAnnotationView(annotation: annotation, reuseIdentifier: reuseId)
        pinView!.image = UIImage(named:"pin")
        pinView?.canShowCallout = true
        pinView?.annotation
        let button : UIButton = UIButton(type: UIButtonType.DetailDisclosure)
        button.setImage(UIImage(named: "pin_arrow")?.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal), forState:UIControlState.Normal)
        pinView!.rightCalloutAccessoryView = button

        let vw: UIView = UIView(frame: CGRectMake(0, 0, 40, 50))
        let label: UILabel = UILabel(frame: CGRectMake(10, 0, 40, 50))
        label.font = UIFont.init(name: "Roboto-Bold", size: 20)
        label.textColor = UIColor(red:17/255.0, green:97/255.0, blue:172/255.0, alpha: 1.0)
        label.numberOfLines = 1
        for myObj in arrOfPinsOnMap where myObj.coordinate.latitude == pinView!.annotation!.coordinate.latitude && myObj.coordinate.longitude == pinView!.annotation!.coordinate.longitude && myObj.title == (pinView?.annotation?.title)!{
            label.text = myObj.sale
            if(myObj.sale != ""){
                vw.addSubview(label)
                if(label.text!.characters.count == 2){
                    vw.frame.size.width = 35
                    label.frame.size.width = 35
                } else if(label.text!.characters.count == 3){
                    vw.frame.size.width = 47
                    label.frame.size.width = 47
                } else if(label.text!.characters.count == 4){
                    label.frame.size.width = 67
                    vw.frame.size.width = 67
                } else if(label.text!.characters.count > 4){
                    label.frame.size.width = 80
                    vw.frame.size.width = 80
                }

                pinView!.leftCalloutAccessoryView = vw
            }
        }

我有这种方法在针脚上显示TAP后的View。我可以在左侧调整我的标签尺寸，但标题保持固定大小。标题必须始终可见。

Answer 1

如您所知，标准MapKit标注具有标题和左右附件视图，看起来您已经发现标注的标题在截断之前可以显示的文本数量有限，我们似乎没有访问标签视图来改变它。

如果您能够定位iOS 9及更高版本，则标题下方会显示额外的detailCalloutAccessoryView。不幸的是，您不能将标题留空并将所有文本放在详细视图中，因为在点击时标注根本不会打开，因此您需要在标题中添加某种文本。

如果你无法使用它或者你需要支持iOS 8，那么你需要做一个自定义标注。这并不困难。创建一个MKAnnotationView子类，其具有标注所需的外观，然后当您在mapView(_:didSelectAnnotationView:)中检测到正在点击的标记时，在与标记相同的位置添加特殊标注注释。

这是一种方法：

class MyAnnotation: NSObject, MKAnnotation
{
    var coordinate: CLLocationCoordinate2D = CLLocationCoordinate2D(latitude: 49.5, longitude: -123.0)
    var title: String? = " "
}

class CalloutAnnotation: MyAnnotation { } // Special annotation class for the callout

let calloutRect = CGRect(origin: CGPointZero, size: CGSize(width: 200, height: 100))

class CalloutAnnotationView: MKAnnotationView
{
    var label: UILabel

    init()
    {
        label = UILabel(frame: CGRectInset(calloutRect, 8.0, 8.0))
        label.textAlignment = .Center
        label.numberOfLines = 0

        super.init(frame: calloutRect)

        self.addSubview(label)
        self.backgroundColor = UIColor.whiteColor()
        self.centerOffset = CGPoint(x: 0.0, y: -(calloutRect.size.height / 2))
        self.layer.cornerRadius = 6.0
    }

    required init?(coder aDecoder: NSCoder)
    {
        label = UILabel(frame: CGRectInset(calloutRect, 8.0, 8.0))
        super.init(coder: aDecoder)
    }
}

class ViewController: UIViewController, MKMapViewDelegate
{
    let calloutAnnotation = CalloutAnnotation()

    @IBOutlet weak var mapView: MKMapView!

    override func viewWillAppear(animated: Bool)
    {
        super.viewWillAppear(animated)
        mapView.addAnnotation(MyAnnotation())
    }

    func mapView(mapView: MKMapView, viewForAnnotation annotation: MKAnnotation) -> MKAnnotationView?
    {
        if annotation is CalloutAnnotation
        {
            let calloutView = CalloutAnnotationView()
            calloutView.label.text = "This is a custom callout that can look however you want."
            return calloutView
        }
        else
        {
            let reuseIdentifier = "pinView"
            let pinView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseIdentifier) ??
                          MKAnnotationView(annotation: annotation, reuseIdentifier: reuseIdentifier)

            pinView.image = UIImage(named: "Pin")
            pinView.canShowCallout = false

            return pinView
        }
    }

    func mapView(mapView: MKMapView, didSelectAnnotationView view: MKAnnotationView)
    {
        if let coordinate = view.annotation?.coordinate
        {
            calloutAnnotation.coordinate = coordinate
            mapView.addAnnotation(calloutAnnotation)
        }
    }

    func mapView(mapView: MKMapView, didDeselectAnnotationView view: MKAnnotationView)
    {
        mapView.removeAnnotation(calloutAnnotation)
    }
}

视图只是一个常规视图，可以响应触摸等。这仍然不完美，因为当标注出现时你丢失了'pop'动画，但如果你需要，你可以添加更多的工作至。我没有尝试过，但我确实在某个时刻获得了动画效果，所以我很确定它是可能的。

Swift：MKAnnotation长标题文本

1 个答案: