在编译我的项目时，编译器卡在这个类上，在尝试构建大约5分钟后，我收到一条消息，告诉我我已经没有系统内存并关闭一些应用程序以继续。这段代码中是否有可能导致编译器崩溃的内容？
我正在使用XCode9，因为我的整台计算机都崩溃了，这可能是XCode的错误吗？
import UIKit
class ConferenceNumberViewController: UITableViewController, UINavigationControllerDelegate {
let sections = ["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"]
let countries = CallIn.Data.allCountries
var indexedCountries =
[
"A": [String](),
"B": [String](),
"C": [String](),
"D": [String](),
"E": [String](),
"F": [String](),
"G": [String](),
"H": [String](),
"I": [String](),
"J": [String](),
"K": [String](),
"L": [String](),
"M": [String](),
"N": [String](),
"O": [String](),
"P": [String](),
"Q": [String](),
"R": [String](),
"S": [String](),
"T": [String](),
"U": [String](),
"V": [String](),
"W": [String](),
"X": [String](),
"Y": [String](),
"Z": [String]()
]
var countryNumberIndex: Int = 0
var indexedConferenceNumbers = CallIn.Data.indexedConferenceNumbers
var selectedConferenceNumber: CallIn.ConferenceNumber!
override func viewDidLoad() {
super.viewDidLoad()
countryAndConference = true
// Do any additional setup after loading the view.
//hide back button according to design
navigationItem.setHidesBackButton(true, animated: false)
for section in sections {
for country in countries {
let searchCharacter: Character = section.characters.first!
let countryCheck: Character = country.characters.first!
let compare = countryCheck == searchCharacter
if compare {
indexedCountries[section]!.append(country)
}
}
}
// indexedConferenceNumbers = indexedConferenceNumbers.sort(sortFunc) // moved the sorting to the Data class
}
/*func sortFunc(num1: CallIn.ConferenceNumber, num2: CallIn.ConferenceNumber) -> Bool {
return num1.country == num2.country ? (num1.typeOfNumber > num2.typeOfNumber) : (num1.country < num2.country)
}*/ // moved the sorting to the Data class
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// custom section view
override func tableView(_ tableView: UITableView, willDisplayHeaderView view: UIView, forSection section: Int) {
let header: UITableViewHeaderFooterView = view as! UITableViewHeaderFooterView //recast your view as a UITableViewHeaderFooterView
header.contentView.backgroundColor = Design.Colours.lightBlue // make the background light grey
if (accessibilityON){
header.textLabel!.font = UIFont(descriptor: UIFontDescriptor.regularDescriptor(UIFontTextStyle.body.rawValue), size: 0)
} else { header.textLabel!.font = UIFont.systemFont(ofSize: 13)}
// header.textLabel!.textColor = Design.Colours.subtextDarkGrey //make the text dark grey
// header.textLabel!.font = UIFont.systemFontOfSize(13) // set size of text
//header.alpha = 0.5 //make the header transparent
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "CountryCell", for: indexPath)
let country = cell.viewWithTag(511) as! UILabel
let number = cell.viewWithTag(512) as! UILabel
let type = cell.viewWithTag(513) as! UILabel
// we have to calculate the index (jump) because the conference numbers list is single array (there are no sections)
var jump = 0
for index in 0...(indexPath as NSIndexPath).section {
(index == (indexPath as NSIndexPath).section) ? (jump = jump + (indexPath as NSIndexPath).row) : (jump = jump + indexedCountries[sections[index]]!.count)
}
country.text = indexedConferenceNumbers[jump].country
number.text = indexedConferenceNumbers[jump].conferenceNumber
type.text = indexedConferenceNumbers[jump].typeOfNumber
return cell
}
override func numberOfSections(in tableView: UITableView) -> Int {
return sections.count
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return indexedCountries[sections[section]]!.count
}
override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
if (countriesPerSection("\(sections[section])").count == 0) {
return nil
}
return sections[section] as String
}
//index on the right side of the screen
override func sectionIndexTitles(for tableView: UITableView) -> ([String]!){
return self.sections
}
override func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
if (countriesPerSection("\(sections[section])").count == 0) {
return 0.1
}
return 30.0
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let indexPath = self.tableView.indexPathForSelectedRow {
tableView.deselectRow(at: indexPath, animated: true)
let selectedCell = tableView.cellForRow(at: indexPath) as UITableViewCell!
let country = selectedCell?.contentView.viewWithTag(511) as! UILabel
let number = selectedCell?.contentView.viewWithTag(512) as! UILabel
let type = selectedCell?.contentView.viewWithTag(513) as! UILabel
// Set the number to be passed to SettingDetailsViewController after the unwind segue.
selectedConferenceNumber = CallIn.ConferenceNumber(country: country.text!, conferenceNumber: number.text!, typeOfNumber: type.text!, isoCode: "")
}
}
private func countriesPerSection(_ section: String) -> [String] {
var matches = [String]()
for country in indexedCountries["\(section)"]! {
matches.append(country)
}
return matches
}
private func conferenceNumbersPerCountry(_ country: String) -> Array<CallIn.ConferenceNumber> {
var matches = Array<CallIn.ConferenceNumber>()
for numbers in indexedConferenceNumbers {
if numbers.country == country {
let conferenceNumber = CallIn.ConferenceNumber(country: numbers.country, conferenceNumber: numbers.conferenceNumber, typeOfNumber: numbers.typeOfNumber, isoCode: numbers.isoCode)
matches.append(conferenceNumber)
}
}
return matches
}
@IBAction private func goBack(_ sender: UIBarButtonItem) {
self.navigationController!.popViewController(animated: true)
}
}
答案 0 :(得分：3)
Swift编译器可能遇到如此大的字典问题，并尝试推断indexedCountries变量的正确类型。
一种解决方案是提供类型：
var indexedCountries: [String, [String]] =
更好的解决方案是避免使用此类代码。将硬编码字典更改为以下内容：
var indexedCountries = [String, [String]]()
然后在viewDidLoad中你可以填充它：
for letter in sections {
indexedCountries[letter] = [String]()
}
这可以避免大量的额外输入，避免潜在的拼写错误，并使编译器的工作变得非常简单（编译速度更快）。
您也可以将sections的声明更新为：
let sections: [String] = [ "A", ... ]
答案 1 :(得分：0)
降级到XCode 8.3.3为我解决了这个问题。如果我找到一个可以让9.0或9.1工作的话，我会编辑这个答案。