Question

我尝试在swift和Xcode 10中使用mapBox下载不同的区域包。这个想法是，当下载一个包时，另一个将以一个新的区域开始。因此，为此，我编写了以下代码：

func startDowloadMapOffline(step:TravelStep){
    downloadingMapOffline = true
    let region = MGLTilePyramidOfflineRegion(styleURL: MGLStyle.streetsStyleURL, bounds: MGLCoordinateBounds(sw: CLLocationCoordinate2D(latitude: step.lattitudeWest, longitude: step.longitudeWest), ne: CLLocationCoordinate2D(latitude: step.lattitudeNorth, longitude: step.longitudeNorth)), fromZoomLevel: 8, toZoomLevel: 12)

    // Store some data for identification purposes alongside the downloaded resources.
    let userInfo = ["name\(startStepIndex)": "My Offline Pack \(startStepIndex)"]
    let context = NSKeyedArchiver.archivedData(withRootObject: userInfo)
    // Create and register an offline pack with the shared offline storage object.

    MGLOfflineStorage.shared.addPack(for: region, withContext: context) { (pack, error) in
        guard error == nil else {
            // The pack couldn’t be created for some reason.
            self.delegate?.downloadDidFaileWithError(with: "error download")
            return
        }
        // Start downloading.
        pack!.resume()
    }
}

第一个软件包已下载，但是当我传递给第二个软件包时，pack.resume()未启动！在offlinePackProgressDidChange方法中，我注意到当completedRessources等于expectedRessources且具有第一个包的值时，它会直接进入状态...

if completedResources == expectedResources {
    let byteCount = ByteCountFormatter.string(fromByteCount: Int64(pack.progress.countOfBytesCompleted), countStyle: ByteCountFormatter.CountStyle.memory)
    print("Offline pack “\(userInfo["name"] ?? "unknown")” completed: \(byteCount), \(completedResources) resources")

    startStepIndex = startStepIndex + 1

    delegate?.downloadStepTilesDidFinish(num: startStepIndex)
} else {
    // Otherwise, print download/verification progress.
    print("Offline pack “\(userInfo["name"] ?? "unknown")” has \(completedResources) of \(expectedResources) resources — \(progressPercentage * 100)%.")
}

MapBox下载许多包问题

0 个答案: