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[英]View of floating action button not appearing when device orientation changes in swift
[英]Insert a floating action button on UITableView in Swift
我正在嘗試添加一個浮動操作按鈕(不是浮動菜單按鈕),它可以通過單擊導航到下一個視圖控制器。 我沒有正確使用浮動按鈕。 我已經嘗試了下面的代碼,但它沒有在表格視圖上顯示適當的按鈕,因為它與表格一起滾動。 有沒有辦法將按鈕貼在同一個地方而不隨着表格一起滾動?
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)
}
添加到UITableView
所有子視圖都會自動滾動。
您可以做的是將按鈕添加到應用程序 Window ,只需記住在 ViewController 消失時將其刪除。
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)
}
}
在viewWillDisappear
:
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
btn.removeFromSuperview()
}
對於 iOS 13 及更高版本,您可以使用此擴展程序檢查關鍵窗口:
extension UIWindow {
static var key: UIWindow? {
if #available(iOS 13, *) {
return UIApplication.shared.windows.first { $0.isKeyWindow }
} else {
return UIApplication.shared.keyWindow
}
}
}
這是使用 Swift 4.2 的 XCode 10 上的工作示例。
注意FAB按鈕會在view消失時消失,再次加載控制器時會重新出現。
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()
}
}
如果您當前使用 tableViewController 那么不,您必須繼承 UIViewController 將 UItableView 和您的浮動按鈕添加到它
或者您可以覆蓋 scollviewDidScroll 並根據 tableview 當前偏移量更改按鈕 y
將滾動視圖拖動為 IBOutlet 並將其委托給 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)
}
代碼快照
在行動
有一種方法對我有用。 在我的表視圖控制器中,首先定義一個按鈕,然后覆蓋函數scrollViewDidScroll() ,如下所示:
import UIKit
class MyTableViewController: UITableViewController {
private let button = UIButton(type: UIButton.ButtonType.custom) as UIButton
override func viewDidLoad() {
let bottomImage = UIImage(named: "yourImage.png")
let yPst = self.view.frame.size.height - 55 - 20
button.frame = CGRect(x: 12, y: yPst, width: 55, height: 55)
button.setImage(bottomImage, for: .normal)
button.autoresizingMask = [.flexibleTopMargin, .flexibleRightMargin]
button.addTarget(self, action: #selector(buttonClicked(_:)), for:.touchUpInside)
button.layer.shadowRadius = 3
button.layer.shadowColor = UIColor.lightGray.cgColor
button.layer.shadowOpacity = 0.9
button.layer.shadowOffset = CGSize.zero
button.layer.zPosition = 1
view.addSubview(button)
}
override func scrollViewDidScroll(_ scrollView: UIScrollView) {
let off = self.tableView.contentOffset.y
let yPst = self.view.frame.size.height
button.frame = CGRect(x: 12, y:off + yPst, width: button.frame.size.width, height: button.frame.size.height)
}
@objc private func buttonClicked(_ notification: NSNotification) {
// do something when you tapped the button
}
}
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