         button.setImage(UIImage(named: "item_mic"), forState: .Normal)
         button.tintColor = UIColor.messageToolBarColor()
         button.tintAdjustmentMode = .Normal
-        button.addTarget(self, action: "toggleRecordVoice", forControlEvents: UIControlEvents.TouchUpInside)
+        button.addTarget(self, action: #selector(toggleRecordVoice), forControlEvents: UIControlEvents.TouchUpInside)
         return button
     }()
 

    var conversation: Conversation? {
        willSet {
            if let _ = newValue {
                NSNotificationCenter.defaultCenter().addObserver(self, selector: "updateDraft:", name: Notification.updateDraft, object: nil)
            }
        }
    }

            // 刚刚输入 @

            if text.hasSuffix("@") {
                mentionUsernameRange = text.endIndex.advancedBy(-1)..<text.endIndex
                initMentionUserAction?()
                return
            }
