ios - 无法在 WatchOS 3 中更新 Apple Watch 并发症

Question

我无法在 WatchOS 3 中更新/刷新 Apple Watch Complication。我在我的 ComplicationController.swift 文件中使用了以下代码。

func getSupportedTimeTravelDirections(for complication: CLKComplication, withHandler handler: @escaping (CLKComplicationTimeTravelDirections) -> Void) {
    handler([.forward])
}

func getTimelineStartDate(for complication: CLKComplication, withHandler handler: @escaping (Date?) -> Void) {
    handler(Date())
}

func getTimelineEndDate(for complication: CLKComplication, withHandler handler: @escaping (Date?) -> Void) {
    handler(Date(timeIntervalSinceNow: 60 * 30))
}

我还尝试从 ExtensionDelegate.swift 中的处理后台任务方法安排更新，但它似乎也不起作用。

func scheduleNextRefresh() {
    let fireDate = Date(timeIntervalSinceNow: 30 * 60)
    let userInfo = ["lastActiveDate" : Date(),
                    "reason" : "updateWeekNumber"] as Dictionary

    WKExtension.shared().scheduleBackgroundRefresh(withPreferredDate: fireDate, userInfo: userInfo as NSSecureCoding) { (error) in
        if error == nil {
            print("Succesfully updated week number")
        }
    }
}

func handle(_ backgroundTasks: Set<WKRefreshBackgroundTask>) {
    for task: WKRefreshBackgroundTask in backgroundTasks {
        if WKExtension.shared().applicationState == .background {
            if task is WKApplicationRefreshBackgroundTask {
                print("Task received")
                scheduleNextRefresh()
            }
        }
        task.setTaskCompleted()
    }
}

Answer 1

WKRefreshBackgroundTask 本身不会更新任何东西，它只是允许您的应用程序进入事件状态并运行代码(放置在 print("Task received") 行附近)这将更新您的并发症。请记住，WKRefreshBackgroundTask 的数量是有限的。

Complication 可以这样更新:

let server = CLKComplicationServer.sharedInstance()

// if you want to add new entries to the end of timeline
server.activeComplications?.forEach(server.extendTimeline)

// if you want to reload all the timeline, which according to snippets looks like your case
server.activeComplications?.forEach(server.reloadTimeline)

这将导致系统调用 CLKComplicationDataSource 的 getCurrentTimelineEntry(for:withHandler:) 方法，您可以在其中准备并返回更新的条目。

有关并发症更新的更多信息 in documentation .有关后台任务的更多信息 in WWDC16 session .