iOS Dev:在MapBox中为用户注释使用自定义图像 [英] iOS Dev: Using a custom image for the user annotation in MapBox

问题描述

我对IOS开发非常陌生，因此其中一些似乎很明显.我尝试结合自定义用户注释的示例和在地图上标记图像的地方

I'm very new to IOS development so some of this might seem obvious. I've tried combining the examples for customize the user annotation and marking a place on the map with an image

我觉得我需要添加以下代码行，并以某种方式将此代码附加到第一个链接中描述的用户注释中，但是我不知道如何执行此操作.我猜想我也可以将其中一些功能插入customUserLocationAnnotationView中，但是没有明显的迹象表明将其放置在该类中的位置.

I feel like I need to add the following lines of code and somehow attach this code to the user annotation described in the first link, but I have no idea how to do this. I'm guessing I could also insert some of these functions into the customUserLocationAnnotationView, but there is no obvious indicator of where to place this within that class.

func mapView(_ mapView: MGLMapView, imageFor annotation: MGLAnnotation) -> MGLAnnotationImage? {
var annotationImage = mapView.dequeueReusableAnnotationImage(withIdentifier: "pisa")

if annotationImage == nil {
          var image = UIImage(named: "pisavector")!
          image = image.withAlignmentRectInsets(UIEdgeInsets(top: 0, left: 0, bottom: image.size.height/2, right: 0))
          annotationImage = MGLAnnotationImage(image: image, reuseIdentifier: "pisa")
     }
     return annotationImage
}

func mapView(_ mapView: MGLMapView, annotationCanShowCallout annotation: MGLAnnotation) -> Bool {
     return true
}

编辑

我不只是想将图像放在这样的随机位置

I don't just want to put an image in a random location like this

我希望图像以用户注释为中心，并且当用户移动时，图像也会移动，就像下面的图像

I want the image to be centered on the user annotation, and when the user moves, the image will also move, like the image below

作为旁注

我还收到错误无法渲染和更新ViewController的自动自动布局状态(BYZ-38-tOr):代理崩溃了Main.storyboard"，但我认为这并不重要，因为我的程序仍然可以在模拟器上正常构建并运行.

I'm also getting the error 'Failed to render and update auto auto layout status for ViewController (BYZ-38-tOr): The agent crashed Main.storyboard' but I don't think that's important, because my program still builds and runs on the simulator fine.

推荐答案

override func viewDidLoad() {
    super.viewDidLoad()
    let mapView = MGLMapView(frame: view.bounds)
    mapView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
    mapView.delegate = self

    mapView.userTrackingMode = .followWithHeading
    mapView.showsUserHeadingIndicator = true
    view.addSubview(mapView)
}  

func mapView(_ mapView: MGLMapView, viewFor annotation: MGLAnnotation) -> MGLAnnotationView? {
// Substitute our custom view for the user location annotation. This custom view is defined below.
    if annotation is MGLUserLocation && mapView.userLocation != nil {
        return CustomUserLocationAnnotationView()
    }
    return nil
}

// Create a subclass of MGLUserLocationAnnotationView.
class CustomUserLocationAnnotationView: MGLUserLocationAnnotationView {
    ...
}

请看以下示例: https://www.mapbox.com/ios-sdk/maps/examples/user-location-annotation/

CustomUserLocationAnnotationView中有一个名为setupLayers的方法.可变点是CALayer，因此您可以将UIImage添加到CALayer.如下更改私有函数setupLayers()中的代码:

There is a method called setupLayers in CustomUserLocationAnnotationView. variable dot is a CALayer, so you can add a UIImage to a CALayer. Change the code in private func setupLayers() like below:

dot = CALayer()
let myImage = UIImage(named: "star")?.cgImage
dot.contents = myImage
layer.addSublayer(dot)

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