我正在使用widgetkit扩展的应用程序中工作。我有一个wierd问题，如小部件在开发端正确显示，但当我使应用程序运行时，它向用户显示空白（黑色）小部件。
开发应用程序时的屏幕截图。

屏幕截图，而使应用程序活。

下面是我的小部件的代码

import SwiftUI
import WidgetKit
import UIKit

private struct Provider: TimelineProvider {

func placeholder(in context: Context) -> SimpleEntry {
    SimpleEntry(date: Date(), water: drunkGlassesInML.convertInMLfromLTR())
}

func getSnapshot(in context: Context, completion: @escaping (SimpleEntry) -> Void) {
    let entry = SimpleEntry(date: Date(), water: drunkGlassesInML.convertInMLfromLTR())
    completion(entry)
}

func getTimeline(in context: Context, completion: @escaping (Timeline<Entry>) -> Void) {
    var entries: [SimpleEntry] = []
    let  entryDate = Calendar.current.date(byAdding: .second, value: 10 , to: Date())!
    let entry = SimpleEntry(date: entryDate, water: drunkGlassesInML.convertInMLfromLTR())
    entries.append(entry)
    let timeline = Timeline(entries: entries, policy: .after(entryDate))
    var timer = Timer()
    timer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { (timer) in
        WidgetCenter.shared.reloadAllTimelines()
        completion(timeline)
    }
}
}
private struct SimpleEntry: TimelineEntry {
   let date: Date
   var water: String
}