Ios Swift-准备检查不起作用
我有三个数组来创建一个tableView和第二个ViewController。一个显示tableView上每个部分的标题,一个显示标题,一个具有每个单元格的链接。当我构建并点击其中一个单元格时: 致命错误:在展开可选值时意外发现nil 在这一行:Ios Swift-准备检查不起作用,ios,arrays,swift,xcode,uitableview,Ios,Arrays,Swift,Xcode,Uitableview,我有三个数组来创建一个tableView和第二个ViewController。一个显示tableView上每个部分的标题,一个显示标题,一个具有每个单元格的链接。当我构建并点击其中一个单元格时: 致命错误:在展开可选值时意外发现nil 在这一行: let url = URL(string: websiteURL)! 现在我相信这是因为我的prepareforsgue不工作,这意味着它没有将数组数据发送到第二个视图控制器(ChannelViewController)。 我还通过添加 print
let url = URL(string: websiteURL)!
现在我相信这是因为我的prepareforsgue不工作,这意味着它没有将数组数据发送到第二个视图控制器(ChannelViewController)。
我还通过添加
print("hello")
转到prepareForSegue函数,查看调试器中是否显示“hello”。但事实并非如此
所以我猜主要的问题是让prepareForSegue做它应该做的事情
以下是FirstViewController代码:
import UIKit
class FirstViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
var headers = ["Bein Sports", "Sky Sports", "Alkass", "Other"]
var channels = [["Bein Sports 1","Bein Sports 2","Bein Sports 3","Bein Sports 4","Bein Sports 5","Bein Sports 6","Bein Sports 7","Bein Sports 8","Bein Sports 9","Bein Sports 10","Bein Sports News"],
["Sky Sports 1","Sky Sports 2","Sky Sports 3","Sky Sports 4","Sky Sports 5"],
["Alkass One", "Alkass Two", "Alkass Three", "Alkass Four", "Alkass Five"],
["BT Sports 1", "BT Sports 2", "Real Madrid TV", "Real Madrid TV 2"]]
var links = [["https://www.google.ca","https://www.facebook.com","https://facebook.com","https://facebook.com","https://facebook.com","https://facebook.com","https://facebook.com","https://facebook.com","https://facebook.com","https://facebook.com","https://facebook.com"],
["https://facebook.com","https://facebook.com","https://facebook.com","https://facebook.com","https://facebook.com"],
["https://facebook.com","https://facebook.com","https://facebook.com","https://facebook.com","https://facebook.com"],
["http://twitter.com","http://facebook.com","http://www.google.com","http://www.instagram.com"]]
var myIndex : IndexPath = IndexPath()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return channels[section].count
}
func numberOfSections(in tableView: UITableView) -> Int {
return channels.count //Rows
}
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return headers[section] //Sections
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.text = channels[indexPath.section][indexPath.row] //TextLabel
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
myIndex = IndexPath(row: indexPath.section, section: indexPath.row)
performSegue(withIdentifier: "segue", sender: self)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?)
{
if (segue.identifier == "segue") {
let viewController = segue.destination as! ChannelViewController
// Now you have a pointer to the child view controller.
// You can save the reference to it, or pass data to it.
viewController.websiteURL = links[myIndex.section][myIndex.row]
print("google")
}
}
}
以下是第二个视图控制器代码:
import UIKit
import WebKit
import AVKit
import AVFoundation
class ChannelViewController: UIViewController {
var webView: WKWebView!
var websiteURL = ""
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
webView = WKWebView()
webView.scrollView.isScrollEnabled = false
view.addSubview(webView)
let url = URL(string: websiteURL)!
let req:URLRequest = URLRequest(url: url)
webView.load(req)
webView.translatesAutoresizingMaskIntoConstraints = false
let width = NSLayoutConstraint(item: webView, attribute: .width, relatedBy: .equal, toItem: view, attribute: .width, multiplier: 1.0, constant: 0) //Constraints
let height = NSLayoutConstraint(item: webView, attribute: .height, relatedBy: .equal, toItem: view, attribute: .height, multiplier: 1.0, constant: 0)
view.addConstraints([width,height]) //Constraints
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
您使用prepare for segue的方式不正确 你应该使用
override func prepare(for segue: UIStoryboardSegue, sender: Any?)
也叫它
self.performSegue(withIdentifier: "segue", sender: nil)
将
func prepareforsgue(segue:UIStoryboardSegue,发送方:AnyObject?)
替换为func prepare(segue:UIStoryboardSegue,发送方:Any?)
,因为您似乎在使用Swift 3。如果它有效,那么它与此相关:作为旁白,强制展开url
会导致崩溃。使用条件展开并显示适当的消息修复prepare(for:sender:)
的签名将修复此问题。将发送者
设置为nil
不会有任何区别。事实上,sender
应该是indepath
,这样就可以避免与myIndex
的整个过程。就发送者的东西达成一致。我把它当作一个通称来写,但没有。我的错,没问题。这与其说是你自己,不如说是对提问者的评论。