[英]How to draw line point by point in Swift
我意識到自己在跟蹤器應用程序中濫用了從服務器檢索的數據。 所以我有這個:
@objc private func updateOnlineTrackWithNewData() {
print("Tick")
if let track = track {
guard track.status == 1 else { return } // is track online?
serverManager.tracks.updateOnlineTrack(for: track, success: { (trackNewPoints) in
//receive new data
guard trackNewPoints.count > 1 else { return }
for point in trackNewPoints {
self.track?.points?.append(point)
self.performSelector(onMainThread: #selector(self.updateOnlineTrackOnMap), with: nil, waitUntilDone: true)
}
}) { (error) in
print(error ?? "Error updating online track")
}
}
}
trackNewPoints基本上是我要附加到主“ track”上的點的數組,而updateOnlineTrackOnMap只是將其打印出來。 updateOnlineTrackWithNewData()函數由計時器觸發,一切正常。 但是我想逐點繪制線以模擬實時運動。 我該如何實現? performSelector似乎不起作用。
如果有幫助,每10秒我會獲得10個新點。
有一種方法可以做到這一點。 創建單獨的類抽屜
protocol Drawable { // add to your controller
func appendPoint(_ point: AnyObject)
func updateOnlineTrackOnMap()
}
class Drawer {
private var timer: Timer? = nil
private var points: [AnyObject] = []
func drawPoints(_ points: [AnyObject],
controller: Drawable) {
self.points = points
timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { [weak self] timer in
guard let point = self?.points.first else {
timer.invalidate()
return
}
DispatchQueue.global(qos: .userInteractive).async {
controller.appendPoint(point)
controller.updateOnlineTrackOnMap()
self?.points.remove(at: 0)
}
}
}
}
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.