[英]How to detect the mapView was moved in Swift and update zoom
I'm trying to set a minimum zoom level on my map in Swift 2. I can't find any documentation on how to restrict a map from being zoomed too far in. What I've decided to try is to monitor for map movement (such as drag or zoom) and then set MKZoomScale
back to a minimum.我正在尝试在 Swift 2 中为我的 map 设置最小缩放级别。我找不到任何关于如何限制 map 被放大太多的文档。我决定尝试监视 map 运动(例如拖动或缩放)然后将
MKZoomScale
设置回最小值。
Most of the answers I've found for regionDidChangeAnimated
are in Objective C, which I don't know and I'm having trouble converting them to Swift.我为
regionDidChangeAnimated
找到的大部分答案都在 Objective C 中,我不知道,我在将它们转换为 Swift 时遇到了麻烦。
I tried implementing @hEADcRASH's answer: https://stackoverflow.com/a/30924768/4106552 , but it doesn't trigger and print anything to the console when the map is moved in the simulator.我尝试实现@hEADcRASH 的答案: https://stackoverflow.com/a/30924768/4106552 ,但当 map 在模拟器中移动时,它不会触发并向控制台打印任何内容。
Can anyone tell me what I'm doing wrong?谁能告诉我我做错了什么? I'm new to Swift, so it could be a small error.
我是 Swift 的新手,所以这可能是一个小错误。 Also, let me know if there is a lightweight way to solve for restricting the zoom level on a map. I'm worried that the monitor for movement will slow down the map animation a bit.
另外,让我知道是否有一种轻量级的方法可以解决限制 map 上的缩放级别的问题。我担心移动监视器会稍微减慢 map animation 的速度。 Thanks for the help.
谢谢您的帮助。
Here is my view controller. import UIKit import Parse import MapKit这是我的观点 controller.import UIKit import Parse import MapKit
class SearchRadiusViewController: UIViewController, CLLocationManagerDelegate, MKMapViewDelegate {
@IBOutlet weak var map: MKMapView!
@IBOutlet weak var menuBtn: UIBarButtonItem!
var locationManager = CLLocationManager()
override func viewDidLoad() {
super.viewDidLoad()
//menu button control
if self.revealViewController() != nil {
menuBtn.target = self.revealViewController()
menuBtn.action = "revealToggle:"
self.view.addGestureRecognizer(self.revealViewController().panGestureRecognizer())
}
//user location
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.requestWhenInUseAuthorization()
locationManager.startUpdatingLocation()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
//set map
let location:CLLocationCoordinate2D = manager.location!.coordinate
let latitude = location.latitude
let longitude = location.longitude
let latDelta:CLLocationDegrees = 0.1
let longDelta:CLLocationDegrees = 0.1
let span:MKCoordinateSpan = MKCoordinateSpanMake(latDelta, longDelta)
let maplocation:CLLocationCoordinate2D = CLLocationCoordinate2DMake(latitude, longitude)
let region:MKCoordinateRegion = MKCoordinateRegionMake(maplocation, span)
map.setRegion(region, animated: true)
//stop updating location, only need user location once to position map.
manager.stopUpdatingLocation()
}
//Attempt to monitor for map movement based on hEADcRASH's answer.
private var mapChangedFromUserInteraction = false
private func mapViewRegionDidChangeFromUserInteraction() -> Bool {
let view = self.map.subviews[0]
// Look through gesture recognizers to determine whether this region change is from user interaction
if let gestureRecognizers = view.gestureRecognizers {
for recognizer in gestureRecognizers {
if( recognizer.state == UIGestureRecognizerState.Began || recognizer.state == UIGestureRecognizerState.Ended ) {
return true
}
}
}
return false
}
func mapView(mapView: MKMapView, regionWillChangeAnimated animated: Bool) {
print("yes")
mapChangedFromUserInteraction = mapViewRegionDidChangeFromUserInteraction()
if (mapChangedFromUserInteraction) {
// user changed map region
print("user changed map in WILL")
}
}
func mapView(mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
print("yes ddd")
if (mapChangedFromUserInteraction) {
// user changed map region
print("user changed map in Did")
}
}
}
After reviewing and combining a number of other questions/answers and the help of @lorenzoliveto I've got it working in Swift. 在回顾并结合了许多其他问题/答案以及@lorenzoliveto的帮助后,我开始在Swift中使用它。 Please leave a comment if there a better/more lightweight way to achieve the same thing.
如果有更好/更轻巧的方法来实现相同目的,请发表评论。
I added self.map.delegate = self
to the viewDidLoad function. 我将
self.map.delegate = self
添加到viewDidLoad函数。
Below is the code for how I'm monitoring for map movement and then once a user has zoomed in "too far" and the width of the map goes below 2 miles I then zoom out the map using mapView.setRegion
. 下面是有关我如何监视地图移动的代码,然后,一旦用户将“地图”放大到“太远”并且地图的宽度低于2英里,我便使用
mapView.setRegion
缩小地图。
private var mapChangedFromUserInteraction = false
private func mapViewRegionDidChangeFromUserInteraction() -> Bool {
let view = self.map.subviews[0]
// Look through gesture recognizers to determine whether this region change is from user interaction
if let gestureRecognizers = view.gestureRecognizers {
for recognizer in gestureRecognizers {
if( recognizer.state == UIGestureRecognizerState.Began || recognizer.state == UIGestureRecognizerState.Ended ) {
return true
}
}
}
return false
}
func mapView(mapView: MKMapView, regionWillChangeAnimated animated: Bool) {
mapChangedFromUserInteraction = mapViewRegionDidChangeFromUserInteraction()
if (mapChangedFromUserInteraction) {
// user will change map region
print("user WILL change map.")
// calculate the width of the map in miles.
let mRect: MKMapRect = mapView.visibleMapRect
let eastMapPoint = MKMapPointMake(MKMapRectGetMinX(mRect), MKMapRectGetMidY(mRect))
let westMapPoint = MKMapPointMake(MKMapRectGetMaxX(mRect), MKMapRectGetMidY(mRect))
let currentDistWideInMeters = MKMetersBetweenMapPoints(eastMapPoint, westMapPoint)
let milesWide = currentDistWideInMeters / 1609.34 // number of meters in a mile
print(milesWide)
print("^miles wide")
// check if user zoomed in too far and zoom them out.
if milesWide < 2.0 {
var region:MKCoordinateRegion = mapView.region
var span:MKCoordinateSpan = mapView.region.span
span.latitudeDelta = 0.04
span.longitudeDelta = 0.04
region.span = span;
mapView.setRegion(region, animated: true)
print("map zoomed back out")
}
}
}
func mapView(mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
if (mapChangedFromUserInteraction) {
// user changed map region
print("user CHANGED map.")
print(mapView.region.span.latitudeDelta)
print(mapView.region.span.longitudeDelta)
// calculate the width of the map in miles.
let mRect: MKMapRect = mapView.visibleMapRect
let eastMapPoint = MKMapPointMake(MKMapRectGetMinX(mRect), MKMapRectGetMidY(mRect))
let westMapPoint = MKMapPointMake(MKMapRectGetMaxX(mRect), MKMapRectGetMidY(mRect))
let currentDistWideInMeters = MKMetersBetweenMapPoints(eastMapPoint, westMapPoint)
let milesWide = currentDistWideInMeters / 1609.34 // number of meters in a mile
print(milesWide)
print("^miles wide")
// check if user zoomed in too far and zoom them out.
if milesWide < 2.0 {
var region:MKCoordinateRegion = mapView.region
var span:MKCoordinateSpan = mapView.region.span
span.latitudeDelta = 0.04
span.longitudeDelta = 0.04
region.span = span;
mapView.setRegion(region, animated: true)
print("map zoomed back out")
}
}
UPDATE: 3/7, I discovered an interesting bug in the implementation above. 更新:3/7,我在上面的实现中发现了一个有趣的错误。 On the simulator it works fine when clicking to zoom, but when you use the pinch to zoom (option + click) the simulator stops allowing you to drag the map around after it animates the zoom back out.
在模拟器上,单击以放大时效果很好,但是当您使用双指进行缩放(选项+单击)时,模拟器将停止,允许您在将缩放动画化后再拖动地图。 This also happened on the beta version on my iphone.
这也发生在我iPhone的Beta版上。 I added
dispatch_async
around the blocks that animate that map back to their position and it appears to be working on the simulator. 我在将地图动画化回其位置的块周围添加了
dispatch_async
,它似乎正在模拟器上运行。 It no longer appears frozen after it animates and I can continue to drag around the map and try to zoom in. 设置动画后,它不再显示为冻结状态,我可以继续在地图上拖动并尝试放大。
dispatch_async(dispatch_get_main_queue(), {
var region:MKCoordinateRegion = mapView.region
var span:MKCoordinateSpan = mapView.region.span
span.latitudeDelta = 0.04
span.longitudeDelta = 0.04
region.span = span;
mapView.setRegion(region, animated: true)
print("map zoomed back out")
})
The solution that works for me is one where I set the zoom range.对我有用的解决方案是我设置缩放范围的解决方案。 This approach may not have been available at the time the question was asked.
在提出问题时,此方法可能不可用。 The code fragment below is what I use.
下面的代码片段是我使用的。 I'm not entirely sure what the distance units are, but I believe they are meters.
我不完全确定距离单位是什么,但我相信它们是米。 Figuring out what range works in a given instance may be a matter of trial and error.
弄清楚在给定实例中什么范围有效可能是一个反复试验的问题。
let mapView = MKMapView(frame: .zero)
let zoomRange = MKMapView.CameraZoomRange(
minCenterCoordinateDistance: 120000,
maxCenterCoordinateDistance: 1600000
)
mapView.cameraZoomRange = zoomRange
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