     }
 
     //累加时间
-    func timeButtonTapped(sender:  UIButton) {
+    func timeButtonTapped(sender: UIButton) {
         let (_, seconds) = timeButtonInfos[sender.tag]
         remainingSeconds += seconds
     }
-    
+
     func updateTimer(timer: NSTimer) {
         remainingSeconds -= 1
-        
+
         // 弹出警告窗口,提示倒计时完成
         if remainingSeconds <= 0 {
             let alert = UIAlertView()
-            
+
             alert.title = "计时完成"
             alert.message = ""
             alert.addButtonWithTitle("OK")
             alert.show()
         }
     }
-    
+
     ///
-    
+
     func setSettingButtonsEnabled(enabled: Bool) {
         for button in timeButtons! {
-            button.enabled = false
+            button.enabled = enabled
             button.alpha = enabled ? 1.0 : 0.3
         }
-        
+
         clearButton!.enabled = enabled
         clearButton!.alpha = enabled ? 1.0 : 0.3
     }
-    
+
     //注册系统通知
     func createAndFireLocalNotificationAfterSeconds(seconds: Int) {
-        
+
         UIApplication.sharedApplication().cancelAllLocalNotifications()
         let notification = UILocalNotification()
-        
+
         let timeIntervalSinceNow = Double(seconds)
-        
+
         notification.fireDate = NSDate(timeIntervalSinceNow:timeIntervalSinceNow);
-        
+
         notification.timeZone = NSTimeZone.systemTimeZone()
         notification.alertBody = "计时完成！"
-        
+
         UIApplication.sharedApplication().scheduleLocalNotification(notification)
-        
-    }
-    
+
+    }
+
 }
 

        setupTimeLabel()
        setuptimeButtons()
        setupActionButtons()
    }

    override func didReceiveMemoryWarning() {

    ///Actions & Callbacks
    func startStopButtonTapped(sender: UIButton) {
        isCounting = !isCounting //切换了isCounting的状态

        if isCounting {
            createAndFireLocalNotificationAfterSeconds(remainingSeconds)
        } else {
