Xcode iOS 8 Swift:单击按钮时无法取消隐藏/隐藏UIView

这让我快发疯了。我试图取消隐藏一个隐藏的UIView按钮点击，但它不工作。这是密码

import UIKit
class DownloadViewController: UIViewController {

    @IBOutlet var activityView: UIView!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        self.activityView.hidden = true
    }

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

    @IBAction func downloadAction(sender: AnyObject) {
        self.activityView.hidden = false
    }    
}

---

请帮帮我。这让我抓狂，因为它没有做这么简单的事情。

确保您的插座连接到Interface Builder中的正确按钮，尝试通过ctrl键将其从IB中的按钮拖动到@IBOutlet代码来再次连接。

此代码有效，您是否收到错误或按钮没有任何作用？

Swift 3

导入UIKit 类DownloadViewController:UIViewController{

@IBOutlet var activityView: UIView!

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    self.activityView.isHidden = true
}

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

@IBAction func downloadAction(sender: AnyObject) {
    self.activityView.isHidden = false
}    

---

}

这对我很有用。您的下载操作是否被调用？