快速注释不同图像

Question

我设法在Swift中为注解图钉获得了一个自定义图标，但是现在我仍然对2个不同的注解使用不同的图像。现在，一个按钮会向地图添加注释。应该有另一个按钮，该按钮也添加了注释，但带有另一个图标。有没有办法为此使用复用ID？class ViewController: UIViewController, MKMapViewDelegate {@IBOutlet weak var Map: MKMapView!@IBAction func btpressed(sender: AnyObject) {    var lat:CLLocationDegrees = 40.748708    var long:CLLocationDegrees = -73.985643    var latDelta:CLLocationDegrees = 0.01    var longDelta:CLLocationDegrees = 0.01    var span:MKCoordinateSpan = MKCoordinateSpanMake(latDelta, longDelta)    var location:CLLocationCoordinate2D = CLLocationCoordinate2DMake(lat, long)    var region:MKCoordinateRegion = MKCoordinateRegionMake(location, span)    Map.setRegion(region, animated: true)    var information = MKPointAnnotation()    information.coordinate = location    information.title = "Test Title!"    information.subtitle = "Subtitle"    Map.addAnnotation(information)}func mapView(mapView: MKMapView!, viewForAnnotation annotation: MKAnnotation!) -> MKAnnotationView! {    if !(annotation is MKPointAnnotation) {        return nil    }    let reuseId = "test"    var anView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId)    if anView == nil {        anView = MKAnnotationView(annotation: annotation, reuseIdentifier: reuseId)        anView.image = UIImage(named:"1.png")        anView.canShowCallout = true    }    else {        anView.annotation = annotation    }    return anView}

Answer 1

在viewForAnnotation委托方法中，设置调用该方法所image依据的依据annotation。

一定要做到这一点后视图被出队或创建的（而不是只在if anView == nil部分）。否则，使用出队视图的注释将显示以前使用该视图的注释的图像。

基本而言MKPointAnnotation，一种区分注释的粗略方法是通过注释，title但这不是很灵活。

更好的方法是使用实现MKAnnotation协议的自定义注释类（一种简便的方法是子类化MKPointAnnotation），并添加所需的任何属性以帮助实现自定义逻辑。

在自定义类中，添加一个属性，例如imageName，您可以使用该属性基于注释自定义图像。

此示例子类MKPointAnnotation：

class CustomPointAnnotation: MKPointAnnotation {

    var imageName: String!

}

创建类型的注释CustomPointAnnotation并设置其imageName：

var info1 = CustomPointAnnotation()

info1.coordinate = CLLocationCoordinate2DMake(42, -84)

info1.title = "Info1"

info1.subtitle = "Subtitle"

info1.imageName = "1.png"

var info2 = CustomPointAnnotation()

info2.coordinate = CLLocationCoordinate2DMake(32, -95)

info2.title = "Info2"

info2.subtitle = "Subtitle"

info2.imageName = "2.png"

在中viewForAnnotation，使用imageName属性设置视图的image：

func mapView(mapView: MKMapView!, viewForAnnotation annotation: MKAnnotation!) -> MKAnnotationView! {

    if !(annotation is CustomPointAnnotation) {

        return nil

    }

    let reuseId = "test"

    var anView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId)

    if anView == nil {

        anView = MKAnnotationView(annotation: annotation, reuseIdentifier: reuseId)

        anView.canShowCallout = true

    }

    else {

        anView.annotation = annotation

    }

    //Set annotation-specific properties **AFTER**

    //the view is dequeued or created...

    let cpa = annotation as CustomPointAnnotation

    anView.image = UIImage(named:cpa.imageName)

    return anView

}

Answer 2

借助Anna和Fabian Boulegue的iOS Swift代码：

import UIKit

import MapKit

class ViewController: UIViewController, MKMapViewDelegate {

    @IBOutlet weak var mapView: MKMapView!

    override func viewDidLoad() {

        super.viewDidLoad()

        self.mapView.delegate = self

        var info1 = CustomPointAnnotation()

        info1.coordinate = CLLocationCoordinate2DMake(26.889281, 75.836042)

        info1.title = "Info1"

        info1.subtitle = "Subtitle"

        info1.imageName = "flag.png"

        var info2 = CustomPointAnnotation()

        info2.coordinate = CLLocationCoordinate2DMake(26.862280, 75.815098)

        info2.title = "Info2"

        info2.subtitle = "Subtitle"

        info2.imageName = "flag.png"

        mapView.addAnnotation(info1)

        mapView.addAnnotation(info2)

    }

    func mapView(mapView: MKMapView!, viewForAnnotation annotation: MKAnnotation!) -> MKAnnotationView! {

        println("delegate called")

        if !(annotation is CustomPointAnnotation) {

            return nil

        }

        let reuseId = "test"

        var anView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId)

        if anView == nil {

            anView = MKAnnotationView(annotation: annotation, reuseIdentifier: reuseId)

            anView.canShowCallout = true

        }

        else {

            anView.annotation = annotation

        }

        //Set annotation-specific properties **AFTER**

        //the view is dequeued or created...

        let cpa = annotation as CustomPointAnnotation

        anView.image = UIImage(named:cpa.imageName)

        return anView

    }

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

        // Dispose of any resources that can be recreated.

    }

}

class CustomPointAnnotation: MKPointAnnotation {

    var imageName: String!

}

Answer 3

需要将注释向下转换为CustomPointAnnotation。更改为let pickupCustomAnno = annotation as! CustomPointAnnotation