如何在 iOS 8 中使用 Swift 实现本地通知(上)

作者：Jameson Quave， 原文链接 ，原文日期：2015/03/04

译者：小铁匠Linus；校对： shanks ；定稿： numbbbbb

@IBOutlet weak var titleField: UITextField!
@IBOutlet weak var deadlinePicker: UIDatePicker!

@IBAction func savePressed(sender: UIButton) {
}

application.registerUserNotificationSettings(UIUserNotificationSettings(forTypes: .Alert | .Badge | .Sound, categories: nil))  // types are UIUserNotificationType members

struct TodoItem {
  var title: String
  var deadline: NSDate
}

struct TodoItem {
  var title: String
  var deadline: NSDate
  var UUID: String
 
  init(deadline: NSDate, title: String, UUID: String) {
    self.deadline = deadline
    self.title = title
    self.UUID = UUID
  }
}

var isOverdue: Bool {
  return (NSDate().compare(self.deadline) == NSComparisonResult.OrderedDescending) // 截止日期比现在要早
}

class TodoList {
  class var sharedInstance : TodoList {
    struct Static {
      static let instance : TodoList = TodoList()
    }
    return Static.instance
  }
}

private let ITEMS_KEY = "todoItems"
 
func addItem(item: TodoItem) { 
  var todoDictionary = NSUserDefaults.standardUserDefaults().dictionaryForKey(ITEMS_KEY) ?? Dictionary() 
  todoDictionary[item.UUID] = ["deadline": item.deadline, "title": item.title, "UUID": item.UUID] 
  NSUserDefaults.standardUserDefaults().setObject(todoDictionary, forKey: ITEMS_KEY) 
  var notification = UILocalNotification()
  notification.alertBody = "Todo Item /"/(item.title)/" Is Overdue" 
  notification.alertAction = "open" 
  notification.fireDate = item.deadline 
  notification.soundName = UILocalNotificationDefaultSoundName 
  notification.userInfo = ["UUID": item.UUID, ] 
  notification.category = "TODO_CATEGORY"
  UIApplication.sharedApplication().scheduleLocalNotification(notification)
}

@IBAction func savePressed(sender: UIButton) {
    let todoItem = TodoItem(deadline: deadlinePicker.date, title: titleField.text, UUID: NSUUID().UUIDString)
    TodoList.sharedInstance.addItem(todoItem) // schedule a local notification to persist this item
    self.navigationController?.popToRootViewControllerAnimated(true) // return to list view
}

var todoItems: [TodoItem] = []
 
func refreshList() {
    todoItems = TodoList.sharedInstance.allItems()
    if (todoItems.count >= 64) {
        self.navigationItem.rightBarButtonItem!.enabled = false
     }
    tableView.reloadData()
}

func allItems() -> [TodoItem] {
  var todoDictionary = NSUserDefaults.standardUserDefaults().dictionaryForKey(ITEMS_KEY) ?? [:]
  let items = Array(todoDictionary.values)
  return items.map({TodoItem(deadline: $0["deadline"] as! NSDate, title: $0["title"] as! String, UUID: $0["UUID"] as! String!)}).sorted({(left: TodoItem, right:TodoItem) -> Bool in
    (left.deadline.compare(right.deadline) == .OrderedAscending)
}

class TodoTableViewController: UITableViewController {
  var todoItems: [TodoItem] = []
  override func viewDidLoad() {
    super.viewDidLoad()
  }
 
  override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
    refreshList()
  }
 
  func refreshList() {
    todoItems = TodoList.sharedInstance.allItems()
 
    if (todoItems.count >= 64) {
      self.navigationItem.rightBarButtonItem!.enabled = false
    }
    tableView.reloadData()
  }
 
  override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    return 1
  }
 
  override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return todoItems.count
  }
 
  override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier("todoCell", forIndexPath: indexPath) as! UITableViewCell
    let todoItem = todoItems[indexPath.row] as TodoItem
    cell.textLabel?.text = todoItem.title as String!
    if (todoItem.isOverdue) {
      cell.detailTextLabel?.textColor = UIColor.redColor()
    } else {
      cell.detailTextLabel?.textColor = UIColor.blackColor()dequeueReusableCellWithIdentifier:indexPath:
    }
 
    let dateFormatter = NSDateFormatter()
    dateFormatter.dateFormat = "'Due' MMM dd 'at' h:mm a"
    cell.detailTextLabel?.text = dateFormatter.stringFromDate(todoItem.deadline)
    return cell
  }
}

override func viewDidLoad() {
  super.viewDidLoad()
  NSNotificationCenter.defaultCenter().addObserver(self, selector: "refreshList", name: "TodoListShouldRefresh", object: nil)
}

func application(application: UIApplication, didReceiveLocalNotification notification: UILocalNotification) {
  NSNotificationCenter.defaultCenter().postNotificationName("TodoListShouldRefresh", object: self)
}

func applicationDidBecomeActive(application: UIApplication) {      
  NSNotificationCenter.defaultCenter().postNotificationName("TodoListShouldRefresh", object: self)
}

func removeItem(item: TodoItem) {
  for notification in UIApplication.sharedApplication().scheduledLocalNotifications as! [UILocalNotification] {
    if (notification.userInfo!["UUID"] as! String == item.UUID) {
      UIApplication.sharedApplication().cancelLocalNotification(notification)
      break
    }
  }
 
  if var todoItems = NSUserDefaults.standardUserDefaults().dictionaryForKey(ITEMS_KEY) {
    todoItems.removeValueForKey(item.UUID)
    NSUserDefaults.standardUserDefaults().setObject(todoItems, forKey: ITEMS_KEY)
  }
}

override func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
  return true
}
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
  if editingStyle == .Delete {
    var item = todoItems.removeAtIndex(indexPath.row)
    tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)
    TodoList.sharedInstance.removeItem(item)
    self.navigationItem.rightBarButtonItem!.enabled = true
  }
}