以编程方式在 UITableView 上方添加 UITextField
Programatically adding UITextField above UITableView
我正在尝试使用 MusicBrainz API 制作搜索应用程序,其中 API 将 return JSON 与输入的搜索词相匹配的数据用户。
这是我目前的 UI:
import UIKit
import WebKit
class ArtistListViewController: UIViewController{
let tableView = UITableView()
var safeArea: UILayoutGuide!
var artists: [Artists]?
let textField = UITextField()
var searchTerm = "Search"
var webView: WKWebView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
safeArea = view.layoutMarginsGuide
searchBar()
setUpTable()
setUpNavigation()
}
func searchBar(){
view.addSubview(textField)
textField.placeholder = "Search"
textField.frame = CGRect(x: 10,y: 200,width: 300.0,height: 30.0)
textField.borderStyle = UITextField.BorderStyle.line
textField.translatesAutoresizingMaskIntoConstraints = false
//Layout Configs
textField.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
textField.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
textField.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
textField.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
}
func setUpTable(){
view.addSubview(tableView)
ArtistSearchModelData().loadArtists(searchTerm: "Adele"){ [weak self] (artists) in
self?.artists = artists
DispatchQueue.main.async{
self?.tableView.reloadData()
}
}
//populate with data
tableView.delegate = self
tableView.dataSource = self
tableView.register(TableViewCell.self, forCellReuseIdentifier: "cell")
//turn off autoresizing
tableView.translatesAutoresizingMaskIntoConstraints = false
//Layout Configs
tableView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
tableView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
tableView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
}
func setUpNavigation(){
self.navigationItem.title = "Artists"
self.navigationController?.navigationBar.barTintColor = .white
self.navigationController?.navigationBar.isTranslucent = false
self.navigationController?.navigationBar.titleTextAttributes = [
NSAttributedString.Key.foregroundColor: UIColor.orange,
NSAttributedString.Key.font: UIFont(name: "Arial-BoldMT", size: 30)
]
}
}
这是我的 UI 的样子:
如您所见,我的搜索栏完全消失了,我不知道如何呈现它。
我尝试使用 UIStackView 但得到了相同的结果。
我尝试在互联网上搜索并找到了类似的解决方案,但无法使它们中的任何一个起作用。
将 textField 和 tableView 添加到自定义子视图也不会呈现任何内容,可能是因为它们是函数?我是不是用错了方法?
感谢任何帮助!
您将文本字段限制在视图的顶部:
textField.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
然后,您将 table 视图限制在视图顶部:
tableView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
所以您的 table 视图覆盖了您的文本字段。
你可以这样做:
tableView.topAnchor.constraint(equalTo: textField.bottomAnchor).isActive = true
将 table 视图的顶部限制在文本字段的底部。
附带说明一下,您应该限制到视图的 安全区域 ...而不是视图本身:
textField.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor).isActive = true
编辑
这是经过上述修改后的 class(请注意,我注释掉了我无法访问的内容,例如您的 Artist
特定代码):
class ArtistListViewController: UIViewController{
let tableView = UITableView()
var safeArea: UILayoutGuide!
//var artists: [Artists]?
let textField = UITextField()
var searchTerm = "Search"
//var webView: WKWebView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
safeArea = view.safeAreaLayoutGuide
searchBar()
setUpTable()
setUpNavigation()
}
func searchBar(){
view.addSubview(textField)
textField.placeholder = "Search"
// not needed
//textField.frame = CGRect(x: 10,y: 200,width: 300.0,height: 30.0)
textField.borderStyle = UITextField.BorderStyle.line
textField.translatesAutoresizingMaskIntoConstraints = false
//Layout Configs
// constrain Top to safeArea Top
textField.topAnchor.constraint(equalTo: safeArea.topAnchor).isActive = true
textField.leftAnchor.constraint(equalTo: safeArea.leftAnchor).isActive = true
textField.rightAnchor.constraint(equalTo: safeArea.rightAnchor).isActive = true
// don't constrain the bottom
//textField.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
}
func setUpTable(){
view.addSubview(tableView)
// ArtistSearchModelData().loadArtists(searchTerm: "Adele"){ [weak self] (artists) in
// self?.artists = artists
//
// DispatchQueue.main.async{
// self?.tableView.reloadData()
// }
// }
//
// //populate with data
// tableView.delegate = self
// tableView.dataSource = self
// tableView.register(TableViewCell.self, forCellReuseIdentifier: "cell")
//turn off autoresizing
tableView.translatesAutoresizingMaskIntoConstraints = false
//Layout Configs
// constrain Top to textField Bottom
tableView.topAnchor.constraint(equalTo: textField.bottomAnchor).isActive = true
tableView.leftAnchor.constraint(equalTo: safeArea.leftAnchor).isActive = true
tableView.rightAnchor.constraint(equalTo: safeArea.rightAnchor).isActive = true
tableView.bottomAnchor.constraint(equalTo: safeArea.bottomAnchor).isActive = true
}
func setUpNavigation(){
self.navigationItem.title = "Artists"
self.navigationController?.navigationBar.barTintColor = .white
self.navigationController?.navigationBar.isTranslucent = false
self.navigationController?.navigationBar.titleTextAttributes = [
NSAttributedString.Key.foregroundColor: UIColor.orange,
NSAttributedString.Key.font: UIFont(name: "Arial-BoldMT", size: 30)
]
}
}
如果您 运行 按原样编写代码,您应该将搜索文本字段置于(空)table视图上方。
如果您随后取消注释特定于艺术家的代码,它应该可以正常工作。
无法准确找出您使用 UIViewController 而不是 UITableViewController 的原因,因此这是第二个解决方案...
对于这类任务,没有嵌入 UITextField,而是有一个更简单、随时可用的解决方案,称为 UISearchController-
Use a search controller to provide a standard search experience of the
contents of another view controller. When the user interacts with a
UISearchBar, the search controller coordinates with a search results
controller to display the search results.
import UIKit
class TableViewController: UITableViewController, UISearchResultsUpdating, UISearchControllerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
createSearchController()
}
// MARK: - Table view data source
let items = ["item1", "item2", "item3", "item4"]
override func numberOfSections(in tableView: UITableView) -> Int { return 1 }
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { return items.count }
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "identifier", for: indexPath)
cell.textLabel?.text = items[indexPath.row]
cell.detailTextLabel?.text = items[indexPath.row] + " detail"
return cell
}
// MARK: - Search controller
private let searchController = UISearchController(searchResultsController: nil)
func createSearchController(){
searchController.searchResultsUpdater = self
searchController.delegate = self
tableView.tableHeaderView = searchController.searchBar
}
func updateSearchResults(for searchController: UISearchController) {
// Do something with it
let searchedText = searchController.searchBar.text
}
}
最后就是这个样子了
更新约束,它将起作用:
//Layout Configs
textField.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
textField.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
textField.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
textField.heightAnchor.constraint(equalToConstant: 30).isActive = true
tableView.topAnchor.constraint(equalTo: textField.bottomAnchor).isActive = true
tableView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
tableView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
当使用调用两个方法时 searchBar()
setUpTable()
- 您的 tableView 将位于 searchBar 之上。我的意思是您选择调用此方法的顺序
当你像调用它一样调用它时,顶部的一些单元格将隐藏在 searchBar 下。
你可以做这个约束
textField.translatesAutoresizingMaskIntoConstraints = false
textField.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
textField.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
textField.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
tableView.translatesAutoresizingMaskIntoConstraints = false
tableView.topAnchor.constraint(equalTo: textField.bottomAnchor).isActive = true
tableView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
tableView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
或者您可以将搜索栏添加到 navigationBar
let searchController = UISearchController(searchResultsController: nil)
navigationItem.searchController = searchController
navigationItem.searchController?.searchBar.delegate = self
navigationItem.searchController?.obscuresBackgroundDuringPresentation = false
navigationItem.searchController?.hidesNavigationBarDuringPresentation = false
navigationItem.searchController?.searchBar.placeholder = "Enter text here..."
我正在尝试使用 MusicBrainz API 制作搜索应用程序,其中 API 将 return JSON 与输入的搜索词相匹配的数据用户。
这是我目前的 UI:
import UIKit
import WebKit
class ArtistListViewController: UIViewController{
let tableView = UITableView()
var safeArea: UILayoutGuide!
var artists: [Artists]?
let textField = UITextField()
var searchTerm = "Search"
var webView: WKWebView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
safeArea = view.layoutMarginsGuide
searchBar()
setUpTable()
setUpNavigation()
}
func searchBar(){
view.addSubview(textField)
textField.placeholder = "Search"
textField.frame = CGRect(x: 10,y: 200,width: 300.0,height: 30.0)
textField.borderStyle = UITextField.BorderStyle.line
textField.translatesAutoresizingMaskIntoConstraints = false
//Layout Configs
textField.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
textField.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
textField.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
textField.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
}
func setUpTable(){
view.addSubview(tableView)
ArtistSearchModelData().loadArtists(searchTerm: "Adele"){ [weak self] (artists) in
self?.artists = artists
DispatchQueue.main.async{
self?.tableView.reloadData()
}
}
//populate with data
tableView.delegate = self
tableView.dataSource = self
tableView.register(TableViewCell.self, forCellReuseIdentifier: "cell")
//turn off autoresizing
tableView.translatesAutoresizingMaskIntoConstraints = false
//Layout Configs
tableView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
tableView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
tableView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
}
func setUpNavigation(){
self.navigationItem.title = "Artists"
self.navigationController?.navigationBar.barTintColor = .white
self.navigationController?.navigationBar.isTranslucent = false
self.navigationController?.navigationBar.titleTextAttributes = [
NSAttributedString.Key.foregroundColor: UIColor.orange,
NSAttributedString.Key.font: UIFont(name: "Arial-BoldMT", size: 30)
]
}
}
这是我的 UI 的样子:
如您所见,我的搜索栏完全消失了,我不知道如何呈现它。
我尝试使用 UIStackView 但得到了相同的结果。
我尝试在互联网上搜索并找到了类似的解决方案,但无法使它们中的任何一个起作用。
将 textField 和 tableView 添加到自定义子视图也不会呈现任何内容,可能是因为它们是函数?我是不是用错了方法?
感谢任何帮助!
您将文本字段限制在视图的顶部:
textField.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
然后,您将 table 视图限制在视图顶部:
tableView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
所以您的 table 视图覆盖了您的文本字段。
你可以这样做:
tableView.topAnchor.constraint(equalTo: textField.bottomAnchor).isActive = true
将 table 视图的顶部限制在文本字段的底部。
附带说明一下,您应该限制到视图的 安全区域 ...而不是视图本身:
textField.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor).isActive = true
编辑
这是经过上述修改后的 class(请注意,我注释掉了我无法访问的内容,例如您的 Artist
特定代码):
class ArtistListViewController: UIViewController{
let tableView = UITableView()
var safeArea: UILayoutGuide!
//var artists: [Artists]?
let textField = UITextField()
var searchTerm = "Search"
//var webView: WKWebView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
safeArea = view.safeAreaLayoutGuide
searchBar()
setUpTable()
setUpNavigation()
}
func searchBar(){
view.addSubview(textField)
textField.placeholder = "Search"
// not needed
//textField.frame = CGRect(x: 10,y: 200,width: 300.0,height: 30.0)
textField.borderStyle = UITextField.BorderStyle.line
textField.translatesAutoresizingMaskIntoConstraints = false
//Layout Configs
// constrain Top to safeArea Top
textField.topAnchor.constraint(equalTo: safeArea.topAnchor).isActive = true
textField.leftAnchor.constraint(equalTo: safeArea.leftAnchor).isActive = true
textField.rightAnchor.constraint(equalTo: safeArea.rightAnchor).isActive = true
// don't constrain the bottom
//textField.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
}
func setUpTable(){
view.addSubview(tableView)
// ArtistSearchModelData().loadArtists(searchTerm: "Adele"){ [weak self] (artists) in
// self?.artists = artists
//
// DispatchQueue.main.async{
// self?.tableView.reloadData()
// }
// }
//
// //populate with data
// tableView.delegate = self
// tableView.dataSource = self
// tableView.register(TableViewCell.self, forCellReuseIdentifier: "cell")
//turn off autoresizing
tableView.translatesAutoresizingMaskIntoConstraints = false
//Layout Configs
// constrain Top to textField Bottom
tableView.topAnchor.constraint(equalTo: textField.bottomAnchor).isActive = true
tableView.leftAnchor.constraint(equalTo: safeArea.leftAnchor).isActive = true
tableView.rightAnchor.constraint(equalTo: safeArea.rightAnchor).isActive = true
tableView.bottomAnchor.constraint(equalTo: safeArea.bottomAnchor).isActive = true
}
func setUpNavigation(){
self.navigationItem.title = "Artists"
self.navigationController?.navigationBar.barTintColor = .white
self.navigationController?.navigationBar.isTranslucent = false
self.navigationController?.navigationBar.titleTextAttributes = [
NSAttributedString.Key.foregroundColor: UIColor.orange,
NSAttributedString.Key.font: UIFont(name: "Arial-BoldMT", size: 30)
]
}
}
如果您 运行 按原样编写代码,您应该将搜索文本字段置于(空)table视图上方。
如果您随后取消注释特定于艺术家的代码,它应该可以正常工作。
无法准确找出您使用 UIViewController 而不是 UITableViewController 的原因,因此这是第二个解决方案...
对于这类任务,没有嵌入 UITextField,而是有一个更简单、随时可用的解决方案,称为 UISearchController-
Use a search controller to provide a standard search experience of the contents of another view controller. When the user interacts with a UISearchBar, the search controller coordinates with a search results controller to display the search results.
import UIKit
class TableViewController: UITableViewController, UISearchResultsUpdating, UISearchControllerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
createSearchController()
}
// MARK: - Table view data source
let items = ["item1", "item2", "item3", "item4"]
override func numberOfSections(in tableView: UITableView) -> Int { return 1 }
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { return items.count }
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "identifier", for: indexPath)
cell.textLabel?.text = items[indexPath.row]
cell.detailTextLabel?.text = items[indexPath.row] + " detail"
return cell
}
// MARK: - Search controller
private let searchController = UISearchController(searchResultsController: nil)
func createSearchController(){
searchController.searchResultsUpdater = self
searchController.delegate = self
tableView.tableHeaderView = searchController.searchBar
}
func updateSearchResults(for searchController: UISearchController) {
// Do something with it
let searchedText = searchController.searchBar.text
}
}
最后就是这个样子了
更新约束,它将起作用:
//Layout Configs
textField.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
textField.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
textField.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
textField.heightAnchor.constraint(equalToConstant: 30).isActive = true
tableView.topAnchor.constraint(equalTo: textField.bottomAnchor).isActive = true
tableView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
tableView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
当使用调用两个方法时 searchBar()
setUpTable()
- 您的 tableView 将位于 searchBar 之上。我的意思是您选择调用此方法的顺序
当你像调用它一样调用它时,顶部的一些单元格将隐藏在 searchBar 下。
你可以做这个约束
textField.translatesAutoresizingMaskIntoConstraints = false
textField.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
textField.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
textField.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
tableView.translatesAutoresizingMaskIntoConstraints = false
tableView.topAnchor.constraint(equalTo: textField.bottomAnchor).isActive = true
tableView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
tableView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
或者您可以将搜索栏添加到 navigationBar
let searchController = UISearchController(searchResultsController: nil)
navigationItem.searchController = searchController
navigationItem.searchController?.searchBar.delegate = self
navigationItem.searchController?.obscuresBackgroundDuringPresentation = false
navigationItem.searchController?.hidesNavigationBarDuringPresentation = false
navigationItem.searchController?.searchBar.placeholder = "Enter text here..."