ios - 停止离线 MapBox map 重新下载

Question

我正在使用 MapBox 下载离线 map 。这样我的用户就可以在旅行时访问特定区域。
使用 MapBox Offline 文档，MapBox map 似乎总是在有连接时尝试下载(重新下载)。

如何设置我的 MapBox 以便它执行检查存储以查看 map 是否已下载？

func startOfflinePackDownload() {

    let region = MGLTilePyramidOfflineRegion(styleURL: mapView.styleURL, bounds: mapView.visibleCoordinateBounds, fromZoomLevel: mapView.zoomLevel, toZoomLevel: 13)

    let userInfo = ["name": "My Offline Pack"]
    let context = NSKeyedArchiver.archivedData(withRootObject: userInfo)

    MGLOfflineStorage.shared().addPack(for: region, withContext: context) { (pack, error) in
        guard error == nil else {
            // The pack couldn’t be created for some reason.
            print("Error: \(error?.localizedDescription ?? "unknown error")")
            return
        }
        // Start downloading.
        pack!.resume()
    }
}

我找到了下面的代码来检查下载是否已经存在......所以这将在我上面的“startOfflinePackDownload()”函数的开始处进行。
但是，较新版本的 MapBox 无法识别该代码。请问有人可以帮助我吗？

MGLOfflineStorage.sharedOfflineStorage().getPacksWithCompletionHandler { (packs, error) in guard error == nil else {
            return
        }
        for pack in packs {
            let userInfo = NSKeyedUnarchiver.unarchiveObjectWithData(pack.context) as! [String: String]
            if userInfo["name"] == "My Offline Pack" {
                // allready downloaded
                return
            }
        }

Answer 1

见mapbox Doc , MGLOfflinePackStateUnknown = 0 表示瓦片已经下载，所以我们同样可以查看离线包状态:

Code is in Objective c , You can convert to swift

-(void)mapViewDidFinishLoadingMap:(MGLMapView *)mapView {

        NSArray *arrTiles = MGLOfflineStorage.sharedOfflineStorage.packs;


        if (arrTiles.count==0) {
            [self startOfflinePackDownload];
        }

        for (MGLOfflinePack *downloadPack in arrTiles) {
            NSLog(@"title: %@",downloadPack.region.description );

            switch (downloadPack.state) {
                case MGLOfflinePackStateUnknown:
                     [downloadPack requestProgress];
                    break;

                case MGLOfflinePackStateComplete:

                    break;

                case MGLOfflinePackStateInactive:
                    [downloadPack resume];
                    break;

                case MGLOfflinePackStateActive:
                   [self startOfflinePackDownload];
                    break;

                case MGLOfflinePackStateInvalid:
                  //  NSAssert(NO, @"Invalid offline pack at index path %@", indexPath);
                    break;
            }
        }
}