ios 用于注释的 Swift 不同图像

Swift different images for Annotation

提问by Fabian Boulegue

I managed to get a custom icon for a annotation pin in Swift, but now I am still stuck using 2 different images for different annotations. Right now a button adds a annotation to the map. There should be another button that also adds a annotation but with another icon.

我设法在 Swift 中获得了一个注释图钉的自定义图标，但现在我仍然坚持使用 2 个不同的图像进行不同的注释。现在，一个按钮会向地图添加注释。应该有另一个按钮也添加了注释，但带有另一个图标。

Is there a way to use the reuseId for this?

有没有办法为此使用重用 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
}

回答by

In the viewForAnnotationdelegate method, set the imagebased on which annotationthe method is being called for.

在viewForAnnotation委托方法中，设置调用方法的image基础annotation。

Be sure to do this afterthe view is dequeued or created (and not only in the if anView == nilpart). Otherwise, annotations that use a dequeued view will show the image of the annotation that used the view previously.

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，使用出列视图的注释将显示之前使用该视图的注释的图像。

With the basic MKPointAnnotation, one crude way to tell annotations apart is by their titlebut that's not very flexible.

使用 basic MKPointAnnotation，区分注释的一种粗略方法是通过它们，title但这不是很灵活。

A better approach is to use a custom annotation class that implements the MKAnnotationprotocol (an easy way to do that is to subclass MKPointAnnotation) and add whatever properties are needed to help implement the custom logic.

更好的方法是使用实​​现MKAnnotation协议的自定义注释类（一种简单的方法是子类MKPointAnnotation）并添加任何需要的属性来帮助实现自定义逻辑。

In the custom class, add a property, say imageName, which you can use to customize the image based on the annotation.

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

This example subclasses MKPointAnnotation:

此示例子类MKPointAnnotation：

class CustomPointAnnotation: MKPointAnnotation {
    var imageName: String!
}

Create annotations of type CustomPointAnnotationand set their imageName:

创建类型的注释CustomPointAnnotation并设置它们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"

In viewForAnnotation, use the imageNameproperty to set the view's image:

在 中viewForAnnotation，使用imageName属性来设置视图的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
}

回答by Vinod Joshi

iOS Swift Code With Help of Anna and Fabian Boulegue:

在 Anna 和 Fabian Boulgue 的帮助下的 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!
}