在swift 4中的uitableview上插入一个浮动操作按钮

Question

我正在尝试添加一个浮动操作按钮(不是浮动菜单按钮),只需单击一下即可将我导航到下一个视图控制器.我没有正确的浮动按钮.我已经尝试了下面的代码,它没有显示表视图上的相应按钮,因为它与表一起滚动.有没有办法将按钮固定在同一个地方,而不是沿着桌子滚动？

func floatingButton(){
    let btn = UIButton(type: .custom)
    btn.frame = CGRect(x: 285, y: 485, width: 100, height: 100)
    btn.setTitle("All Defects", for: .normal)
    btn.backgroundColor = #colorLiteral(red: 0.1764705926, green: 0.4980392158, blue: 0.7568627596, alpha: 1)
    btn.clipsToBounds = true
    btn.layer.cornerRadius = 50
    btn.layer.borderColor = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)
    btn.layer.borderWidth = 3.0
    btn.addTarget(self,action: #selector(DestinationVC.buttonTapped), for: UIControlEvent.touchUpInside)
    view.addSubview(btn)
}

Answer 1

添加到的所有子视图UITableView都会自动滚动。

您可以做的是将按钮添加到应用程序窗口中，只记得在ViewController消失时将其删除。

var btn = UIButton(type: .custom)
func floatingButton(){
    btn.frame = CGRect(x: 285, y: 485, width: 100, height: 100)
    btn.setTitle("All Defects", for: .normal)
    btn.backgroundColor = #colorLiteral(red: 0.1764705926, green: 0.4980392158, blue: 0.7568627596, alpha: 1)
    btn.clipsToBounds = true
    btn.layer.cornerRadius = 50
    btn.layer.borderColor = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)
    btn.layer.borderWidth = 3.0
    btn.addTarget(self,action: #selector(DestinationVC.buttonTapped), for: UIControlEvent.touchUpInside)
    if let window = UIApplication.shared.keyWindow {
        window.addSubview(btn)
    }
}

并在viewWillDisappear：

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    btn.removeFromSuperview()
}

Answer 2

这是使用 Swift 4.2 的 XCode 10 上的工作示例。

注意FAB按钮会在view消失时消失，再次加载控制器时会重新出现。

import UIKit

class ViewController: UITableViewController {

lazy var faButton: UIButton = {
    let button = UIButton(frame: .zero)
    button.translatesAutoresizingMaskIntoConstraints = false
    button.backgroundColor = .blue
    button.addTarget(self, action: #selector(fabTapped(_:)), for: .touchUpInside)
    return button
}()

override func viewDidLoad() {
    super.viewDidLoad()
    setupTableView()
}

override func viewDidAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    if let view = UIApplication.shared.keyWindow {
        view.addSubview(faButton)
        setupButton()
    }
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    if let view = UIApplication.shared.keyWindow, faButton.isDescendant(of: view) {
        faButton.removeFromSuperview()
    }
}

func setupTableView() {
    tableView.backgroundColor = .darkGray
}

func setupButton() {
    NSLayoutConstraint.activate([
        faButton.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -36),
        faButton.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -36),
        faButton.heightAnchor.constraint(equalToConstant: 80),
        faButton.widthAnchor.constraint(equalToConstant: 80)
        ])
    faButton.layer.cornerRadius = 40
    faButton.layer.masksToBounds = true
    faButton.layer.borderColor = UIColor.lightGray.cgColor
    faButton.layer.borderWidth = 4
}

@objc func fabTapped(_ button: UIButton) {
    print("button tapped")
}

override func numberOfSections(in tableView: UITableView) -> Int {
    return 5
}

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return 3
}

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    return UITableViewCell()
}

override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
    return 64
}

override func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
    return 32
}

override func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
    return UIView()
}
}

Answer 3

如果您当前使用 tableViewController 那么不行，您必须子类化 UIViewController 添加 UItableView 和浮动按钮到它

或者您可以覆盖 scollviewDidScroll 并根据 tableview 当前偏移量更改按钮 y

将滚动视图拖动为 IBOutlet 并将其委托设置给 viewController

   func scrollViewDidScroll(_ scrollView: UIScrollView) {

       let  off = scrollView.contentOffset.y

       btn.frame = CGRect(x: 285, y:   off + 485, width: btn.frame.size.width, height: btn.frame.size.height)
}

代码快照

在行动

看到行动