我正在尝试通过我的网站将iOS应用连接到sql数据库。我已经使用.php文件将数据库连接到我的网站。我正在遵循codewithchris.com上的教程来完成此任务（https://codewithchris.com/iphone-app-connect-to-mysql-database/），但是在尝试在Xcode上构建和运行应用程序时出现错误。
我的错误状态：“线程1：致命错误：在展开可选值时意外发现nil”。如果值为零，则我的程序可能无法正确访问数据库中的信息以获取值。有没有办法修复我的代码以从数据库中获取数据？
Xcode控制台指出：“ 2019-03-10 03：06：29.820695-0500 7655 Clock-It Fix-It [39747：2060656] libMobileGestalt MobileGestalt.c：890：此平台不支持MGIsDeviceOneOfType。 数据已下载”
这是我的代码：
//
// TableViewController.swift
// 7655 Clock-It Fix-It
//
// Created by Kevin Terwelp on 3/9/19.
// Copyright © 2019 Kevin Terwelp. All rights reserved.
//
import UIKit
class TableViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, HomeModelProtocol {
//Properties
var feedItems: NSArray = NSArray()
var selectedJob : JobsModel = JobsModel()
@IBOutlet weak var listTableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
// set delegates and initialize homeModel
self.listTableView.delegate = self
self.listTableView.dataSource = self
let homeModel = HomeModel()
homeModel.delegate = self
homeModel.downloadItems()
}
func itemsDownloaded(items: NSArray) {
feedItems = items
self.listTableView.reloadData()
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
//Return the number of feed items
return feedItems.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
//Retrieve cell
let cellIdentifier: String = "BasicCell"
let myCell: UITableViewCell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier)!
//Get the job to be shown
let item: JobsModel = feedItems[indexPath.row] as! JobsModel
//Get references to labels of cell
myCell.textLabel!.text = item.date
myCell.textLabel!.text = item.time
myCell.textLabel!.text = item.unit
myCell.textLabel!.text = item.jobType
return myCell
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using segue.destination.
// Pass the selected object to the new view controller.
}
*/
}
//
// HomeModel.swift
// 7655 Clock-It Fix-It
//
// Created by Kevin Terwelp on 3/9/19.
// Copyright © 2019 Kevin Terwelp. All rights reserved.
//
import UIKit
import Foundation
protocol HomeModelProtocol: class {
func itemsDownloaded(items: NSArray)
}
class HomeModel: NSObject, URLSessionDataDelegate {
//properties
weak var delegate: HomeModelProtocol!
var data = Data()
let urlPath: String = "https://devbykevt.com/service.php" //this will be changed to the path where service.php lives
func downloadItems() {
let url: URL = URL(string: urlPath)!
let defaultSession = Foundation.URLSession(configuration: URLSessionConfiguration.default)
let task = defaultSession.dataTask(with: url) { (data, response, error) in
if error != nil {
print("Failed to download data")
} else {
print("Data downloaded")
self.parseJSON(data!)
}
}
task.resume()
}
func parseJSON(_ data:Data) {
var jsonResult = NSArray()
do{
jsonResult = try JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions.allowFragments) as! NSArray
} catch let error as NSError {
print(error)
}
var jsonElement = NSDictionary()
let jobs = NSMutableArray()
for i in 0 ..< jsonResult.count
{
jsonElement = jsonResult[i] as! NSDictionary
let job = JobsModel()
//the following insures none of the JsonElement values are nil through optional binding
if let name = jsonElement["Name"] as? String,
let date = jsonElement["Date"] as? String,
let time = jsonElement["Time"] as? String,
let unit = jsonElement["Unit"] as? String,
let jobType = jsonElement["Job Type"] as? String,
let address = jsonElement["Address"] as? String
{
job.name = name
job.date = date
job.time = time
job.unit = unit
job.jobType = jobType
job.address = address
}
jobs.add(job)
}
DispatchQueue.main.async(execute: { () -> Void in
self.delegate.itemsDownloaded(items: jobs)
})
}
}
//
// JobsModel.swift
// 7655 Clock-It Fix-It
//
// Created by Kevin Terwelp on 3/9/19.
// Copyright © 2019 Kevin Terwelp. All rights reserved.
//
import UIKit
import Foundation
class JobsModel: NSObject {
//properties
var name: String?
var date: String?
var time: String?
var unit: String?
var jobType: String?
var address: String?
//empty constructor
override init()
{
}
//construct with @name, @date, @time, @unit, @jobType, and @address parameters
init(name: String, date: String, time: String, unit: String, jobType: String, address: String) {
self.name = name
self.date = date
self.time = time
self.unit = unit
self.jobType = jobType
self.address = address
}
//prints object's current state
override var description: String {
return "Name: \(name), Date: \(date), Time: \(time), Unit: \(unit), Job Type: \(jobType), Address: \(address)"
}
}
感谢所有可以帮助我的人！如果需要更多信息，请告诉我。