Swift 使用 uiTextView 关闭键盘

我相信这并没有那么困难，但我很难找到关于如何使用文本视图而不是文本字段关闭带有返回/完成键的键盘的信息.以下是我到目前为止try 过的内容(适用于文本字段)

非常感谢您的帮助！

//  PostTravelQuestion.swift

class PostTravelQuestion: UIViewController, UITextViewDelegate {

    @IBAction func closepostpage(sender: AnyObject) {
        dismissViewControllerAnimated(true, completion: nil)
    }


    @IBOutlet var postquestion: UITextView!


    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        postquestion.delegate = self
    }

    self addDoneToolBarToKeyboard:self.textView


    /*func textViewShouldEndEditing(textView: UITextView) -> Bool {

        textView.resignFirstResponder()

        return true
    }*/

    /*override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
        postquestion.resignFirstResponder()
        self.view.endEditing(true)
    }*/



    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


    func textViewShouldReturn(textView: UITextView!) -> Bool {
        self.view.endEditing(true);
        return true;
    }
}