在swift中向下滑动时搜索栏

Question

我正在为iOS开发一个社交媒体应用程序

我ViewControllers目前已经嵌入了NavigationController.在我的新闻提要屏幕上,我需要在用户向下滑动时显示搜索栏(并在他向上滑动时隐藏它),其中如果用户输入内容,搜索结果将显示在新闻提要屏幕的顶部.

我试图修补这个,但我对iOS很新,到目前为止还没有设法让它工作.

任何帮助将grately理解和记住,我只几个星期的编程的iOS这样一些深层次的将是有益的.谢谢 !

Answer 1

首先，您需要实施UISwipeGestureRecognizer

将该setup()函数包含在viewDidAppear

func setup() {
    let swipeDown = UISwipeGestureRecognizer(target: self, action: #selector(down))
    swipeDown.direction = .down
    let swipeUp = UISwipeGestureRecognizer(target: self, action: #selector(up))
    swipeUp.direction = .up

    self.view.addGestureRecognizer(swipeDown)
    self.view.addGestureRecognizer(swipeUp)

    searchBar = UISearchBar(frame: CGRect(x: 0.0, y: 0.0, width: self.view.frame.size.width, height: 40.0))
    if let searchBar = searchBar
    {
        searchBar.backgroundColor = UIColor.red
        self.view.addSubview(searchBar)
    }
}

然后你的两个函数 up 和 down

func down(sender: UIGestureRecognizer) {
    print("down")
    //show bar
    UIView.animate(withDuration: 1.0, animations: { () -> Void in
        self.searchBar!.frame = CGRect(x: 0.0, y: 64.0, width: self.view.frame.width, height: 40.0)
    }, completion: { (Bool) -> Void in
    })
}

func up(sender: UIGestureRecognizer) {
    print("up")
    UIView.animate(withDuration: 1.0, animations: { () -> Void in
        self.searchBar!.frame = CGRect(x: 0.0, y: 0.0, width: self.view.frame.width, height: 40.0)
    }, completion: { (Bool) -> Void in
    })
}

您可以添加Bool isShowing以避免不必要的动画。然后，实现搜索栏委托textDidChange以根据用户键入更改搜索结果。

func searchBar(_ searchBar: UISearchBar,textDidChange searchText: String)`

您现在需要做的就是在UISearchController.

注意 使用向上/向下滑动动作可能会干扰屏幕的滚动。UIScreachController