Created by 大劉 liuxing8807@126.com

這里是Apple官網(wǎng)的說明。

A representation of the state of your app at a moment in time.

NSUserActivity是Apple在iOS8之后推出來做Handoff的，它主要用于對(duì)app記錄用戶的操作，后來NSUserActivity主要用來支持：

• Handoff
• SiriKit
• Spolight search results

創(chuàng)建NSUserActivity的流程：

1. 使用app支持的合適的type創(chuàng)建并初始化NSUserActivity對(duì)象， 類型一般約定為reverse-DNS格式，比如com.myCompany.myApp, type需要在Info.plist中使用key為NSUserActivityTypes配置
2. 設(shè)置title
3. 為對(duì)象設(shè)置合適的屬性以讓它支持不同的業(yè)務(wù) isEligibleForHandoff、isEligibleForSearch、isEligibleForPublicIndexing
4. 配置其他屬性
5. 對(duì)于配置了search或public indexing的對(duì)象，配置 contentAttributeSet, keywords, or webpageURL
6. 調(diào)用becomeCurrent()向系統(tǒng)注冊(cè)

支持Handoff
設(shè)置isEligibleForHandoff屬性為true

支持SiriKit
當(dāng)SiriKit需要開啟app的時(shí)候，它會(huì)創(chuàng)建一個(gè)user activity對(duì)象，并且設(shè)置userActivityObj.interaction = INInteraction對(duì)象，具體可以參見SiriKit Programming Guide.

支持Search Results
在未打開任何app的時(shí)候，由上往下拖會(huì)啟用Spotlight:

11.jpg

需要深一步了解Core Spotlight，可以參見：[圖片上傳失敗...(image-55b42-1655180877531)]是官網(wǎng)對(duì)Core Spotlight的說明。

我們做一個(gè)簡(jiǎn)單示例，當(dāng)在Spotlight中搜索One or two or three的時(shí)候啟用我們的App, 并使用User activity做一些事情。
新建一個(gè)iOS 工程：

class RootViewController: UITableViewController {

    private let items: Array<String> = ["One", "Two", "Three"]
    private let activity: NSUserActivity = NSUserActivity(activityType: "daliu")

    override func viewDidLoad() {
        super.viewDidLoad()
        // cellClass: AnyClass
        self.tableView.register(UITableViewCell.classForCoder(), forCellReuseIdentifier: "cellID")
        self.addActivity()
    }

    func addActivity() -> Void {
        // title和keywords都可以在Spotlight搜索結(jié)果中出現(xiàn)
        self.activity.title = "activity title here"
        self.activity.keywords = Set(arrayLiteral: "One", "Two", "Three")
        // 是否將用戶活動(dòng)轉(zhuǎn)交到其他設(shè)備
        // self.activity.isEligibleForHandoff = false
        self.activity.isEligibleForSearch = true
        // 每個(gè)控制器的user activity和搜索結(jié)果都是僅當(dāng)應(yīng)用曾經(jīng)被打開過時(shí)而創(chuàng)建的
        // _activity.eligibleForPublicIndexing = YES;
        // 自動(dòng)被加入到設(shè)備的搜索結(jié)果索引中
        self.activity.becomeCurrent()
    }

    // MARK: - Table view data source
    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return self.items.count
    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cellID", for: indexPath)
        cell.textLabel?.text = self.items[indexPath.row]
        return cell
    }

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        switch indexPath.row {
        case 0:
            let vc = OneViewController()
            self.navigationController?.pushViewController(vc, animated: true)
        case 1:
            let vc = TwoViewController()
            self.navigationController?.pushViewController(vc, animated: true)
        case 2:
            let vc = ThreeViewController()
            self.navigationController?.pushViewController(vc, animated: true)
        default:
            break
        }
    }

    override func restoreUserActivityState(_ activity: NSUserActivity) {
        if activity.title == "One" {
            let vc = OneViewController()
            self.navigationController?.pushViewController(vc, animated: true)
        } else if let _ = activity.title?.elementsEqual("Two") {
            let vc = TwoViewController()
            self.navigationController?.pushViewController(vc, animated: true)
        } else if activity.title?.caseInsensitiveCompare("Three") == ComparisonResult.orderedSame {
            let vc = ThreeViewController()
            self.navigationController?.pushViewController(vc, animated: true)
        }
    }
}

AppDelegate.m

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.
    self.window = UIWindow.init(frame: UIScreen.main.bounds)
    let rootController = UIStoryboard.init(name: "RootViewController", bundle: nil).instantiateInitialViewController() as! RootViewController
    let nivController = UINavigationController(rootViewController: rootController)
    self.window?.rootViewController = nivController
    self.window?.makeKeyAndVisible()
    return true
}

// 監(jiān)聽在Spotlight中的點(diǎn)擊
func application(_ application: UIApplication, continue userActivity: NSUserActivity, restorationHandler: @escaping ([UIUserActivityRestoring]?) -> Void) -> Bool {
    let niv: UINavigationController = self.window?.rootViewController as! UINavigationController
    niv.topViewController?.restoreUserActivityState(userActivity)
    return true
}

這樣，當(dāng)在Spotlight中搜索one時(shí)，就是顯示我們的app, 點(diǎn)擊進(jìn)去就進(jìn)入到了OneViewController.