学习 iOS Widgets 开发之每日步数小组件(一)

每日步数：

class StepsInteractor {
    let healthStore = HKHealthStore()
    let stepCountType = HKObjectType.quantityType(forIdentifier: HKQuantityTypeIdentifier.stepCount)!
    // Access Step Count
    let healthKitTypes: Set = [ HKObjectType.quantityType(forIdentifier: HKQuantityTypeIdentifier.stepCount)! ]
    
    func retrieveStepsWithAuth(completion: @escaping (Double) -> Void) {
        // Check for Authorization
        if (healthStore.authorizationStatus(for: stepCountType) != HKAuthorizationStatus.sharingAuthorized) {
            healthStore.requestAuthorization(toShare: healthKitTypes, read: healthKitTypes) { (success, error) in
                if (success) {
                    // Authorization Successful
                    self.getSteps { (result) in
                        completion(result)
                    }
                } else {
                    completion(-1)
                }
            }
        } else {
            self.getSteps { (result) in
                completion(result)
            }
        }
    }
    
    func getSteps(completion: @escaping (Double) -> Void) {
        let stepsQuantityType = HKQuantityType.quantityType(forIdentifier: .stepCount)!

        let now = Date()
        let startOfDay = now - 2.days
        var interval = DateComponents()
        interval.day = 1
        
        let query = HKStatisticsCollectionQuery(
             quantityType: stepsQuantityType,
             quantitySamplePredicate: nil,
             options: [.cumulativeSum],
             anchorDate: startOfDay,
             intervalComponents: interval)
        
        query.initialResultsHandler = { _, result, error in
                var resultCount = 0.0
                result!.enumerateStatistics(from: startOfDay, to: now) { statistics, _ in
                if let sum = statistics.sumQuantity() {
                    // Get steps (they are of double type)
                    resultCount = sum.doubleValue(for: HKUnit.count())
                } // end if
                // Return
                completion(resultCount)
            }
        }
        
        query.statisticsUpdateHandler = {
            query, statistics, statisticsCollection, error in
            // If new statistics are available
            if let sum = statistics?.sumQuantity() {
                let resultCount = sum.doubleValue(for: HKUnit.count())
                // Return
                completion(resultCount)
            } // end if
        }
        
        healthStore.execute(query)
    }
}

对于授权过了，就直接调用获取步数，否则先授权，后获取数据。

Widget 写法已经足够简单了，直接看代码：

//
//  HealthStepsWidget.swift
//  Widget
//
//  Created by 叶梅树 on 2020/12/12.
//

import WidgetKit
import SwiftUI
import Intents
import SwiftDate

struct HealthStepsProvider: IntentTimelineProvider {
    let stepsInteractor = StepsInteractor()
    func placeholder(in context: Context) -> HealthStepsEntry {
        return HealthStepsEntry(date: Date(), steps: 0)
    }
    
    func getSnapshot(for configuration: HealthStepsIntent, in context: Context, completion: @escaping (HealthStepsEntry) -> Void) {
        let entry = HealthStepsEntry(date: Date(), steps: 0)
        completion(entry)
    }
    
    func getTimeline(for configuration: HealthStepsIntent, in context: Context, completion: @escaping (Timeline<Entry>) -> Void) {
        let currentDate = Date()
        let refreshDate = currentDate + 1.hours
        stepsInteractor.retrieveStepsWithAuth { result in
            let entry = HealthStepsEntry(date: Date(), steps: Int(result))
            let timeline = Timeline(entries: [entry], policy: .after(refreshDate))
            completion(timeline)
        }
    }
}

struct HealthStepsEntry: TimelineEntry {
    public let date: Date
    public let steps: Int
}

struct HealthStepsPlaceholderView : View {
    //这里是PlaceholderView - 提醒用户选择部件功能
    var body: some View {
        HealthStepsView(steps: 0)
    }
}

struct HealthStepsEntryView : View {
    //这里是Widget的类型判断
    @Environment(\.widgetFamily) var family: WidgetFamily
    var entry: HealthStepsProvider.Entry
    
    @ViewBuilder
    var body: some View {
        HealthStepsView(steps: entry.steps)
    }
}

struct HealthStepsWidget: Widget {
    private let kind: String = "HealthSteps"
    public var body: some WidgetConfiguration {
        IntentConfiguration(kind: kind, intent: HealthStepsIntent.self, provider: HealthStepsProvider()) { entry in
            HealthStepsEntryView(entry: entry)
        }
        .configurationDisplayName("每日步数")
        .description("今日步数达到目标了吗？")
        .supportedFamilies([.systemSmall])
        
    }
}

看看 View 视图：

import SwiftUI

struct HealthStepsView: View {
    var steps: Int
    var body: some View {
        VStack(alignment: .leading, spacing: 0.0) {
            Spacer()
            Text(String(steps))
                .font(.footnote)
                .foregroundColor(.gray)
                .lineLimit(1)
            Spacer()
        }.padding(.all)
    }
}

显示很简单：

总结

下一步就是模仿已有的竞品效果：