斯坦福大学 iOS9 2016 年第 6 讲 VCL.swift 文件,错误行 "print("\(logPrefix)Face \(instance)" + msg)"
Stanford iOS9 2016 lecture 6 VCL.swift file, errors with line "print("\(logPrefix)Face \(instance)" + msg)"
在 2016 年斯坦福大学第 6 讲 iOS9 系列讲座中,程序中添加了一个名为 VCL.swift 的文件来演示视图控制器生命周期。
我已经添加了文件,但是对于行 "print("\(logPrefix)Emotions\(instance)" + msg)
和行“print("\(logPrefix)Face \(instance)" + msg)"
,xcode 显示错误,告诉我 "use of unresolved identifier 'instance' "。
有人知道如何解决吗?
下面是第 6 课VCL.swift 的文件
import UIKit
private var faceMVCinstanceCount = 0
func getFaceMVCinstanceCount() -> Int { faceMVCinstanceCount += 1; return faceMVCinstanceCount }
private var emotionsMVCinstanceCount = 0
func getEmotionsMVCinstanceCount() -> Int { emotionsMVCinstanceCount += 1; return emotionsMVCinstanceCount }
var lastLog = NSDate()
var logPrefix = ""
func bumpLogDepth() {
if lastLog.timeIntervalSinceNow < -1.0 {
logPrefix += "__"
lastLog = NSDate()
}
}
// we haven't covered extensions as yet
// but it's basically a way to add methods to a given class
extension FaceViewController
{
func logVCL(msg: String) {
bumpLogDepth()
print("\(logPrefix)Face \(instance) " + msg) //error: use of unresolved identifier 'instance'
}
override func awakeFromNib() {
logVCL("awakeFromNib()")
}
override func viewDidLoad() {
super.viewDidLoad()
logVCL("viewDidLoad()")
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
logVCL("viewWillAppear(animated = \(animated))")
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
logVCL("viewDidAppear(animated = \(animated))")
}
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
logVCL("viewWillDisappear(animated = \(animated))")
}
override func viewDidDisappear(animated: Bool) {
super.viewDidDisappear(animated)
logVCL("viewDidDisappear(animated = \(animated))")
}
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
logVCL("viewWillLayoutSubviews() bounds.size = \(view.bounds.size)")
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
logVCL("viewDidLayoutSubviews() bounds.size = \(view.bounds.size)")
}
override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
super.viewWillTransitionToSize(size, withTransitionCoordinator: coordinator)
logVCL("viewWillTransitionToSize")
coordinator.animateAlongsideTransition({ (context: UIViewControllerTransitionCoordinatorContext!) -> Void in
self.logVCL("animatingAlongsideTransition")
}, completion: { context -> Void in
self.logVCL("doneAnimatingAlongsideTransition")
})
}
}
extension EmotionsViewController
{
func logVCL(msg: String) {
bumpLogDepth()
print("\(logPrefix)Emotions \(instance) " + msg) //error: use of unresolved identifier 'instance'
}
override func awakeFromNib() {
logVCL("awakeFromNib()")
}
override func viewDidLoad() {
super.viewDidLoad()
logVCL("viewDidLoad()")
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
logVCL("viewWillAppear(animated = \(animated))")
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
logVCL("viewDidAppear(animated = \(animated))")
}
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
logVCL("viewWillDisappear(animated = \(animated))")
}
override func viewDidDisappear(animated: Bool) {
super.viewDidDisappear(animated)
logVCL("viewDidDisappear(animated = \(animated))")
}
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
logVCL("viewWillLayoutSubviews() bounds.size = \(view.bounds.size)")
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
logVCL("viewDidLayoutSubviews() bounds.size = \(view.bounds.size)")
}
override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
super.viewWillTransitionToSize(size, withTransitionCoordinator: coordinator)
logVCL("viewWillTransitionToSize")
coordinator.animateAlongsideTransition({ (context: UIViewControllerTransitionCoordinatorContext!) -> Void in
self.logVCL("animatingAlongsideTransition")
}, completion: { context -> Void in
self.logVCL("doneAnimatingAlongsideTransition")
})
}
}
错误:"use of unresolved identifier 'instance'" 表示您正在尝试使用尚未声明的变量。
在您的情况下,EmotionsViewController
(EmotionsViewController.swift) and/or let instance = getFaceMVCinstanceCount()
FaceViewController
( FacialExpression.swift).
只需查看此处提供的完整资源:
Lecture 6: Multiple MVCs
该错误意味着您正在尝试打印 instance
但您没有在任何地方的代码中定义它。两次检查您的代码,您的对象或变量是否带有 instance
标识符。
希望这会有所帮助:)
在 2016 年斯坦福大学第 6 讲 iOS9 系列讲座中,程序中添加了一个名为 VCL.swift 的文件来演示视图控制器生命周期。
我已经添加了文件,但是对于行 "print("\(logPrefix)Emotions\(instance)" + msg)
和行“print("\(logPrefix)Face \(instance)" + msg)"
,xcode 显示错误,告诉我 "use of unresolved identifier 'instance' "。
有人知道如何解决吗?
下面是第 6 课VCL.swift 的文件
import UIKit
private var faceMVCinstanceCount = 0
func getFaceMVCinstanceCount() -> Int { faceMVCinstanceCount += 1; return faceMVCinstanceCount }
private var emotionsMVCinstanceCount = 0
func getEmotionsMVCinstanceCount() -> Int { emotionsMVCinstanceCount += 1; return emotionsMVCinstanceCount }
var lastLog = NSDate()
var logPrefix = ""
func bumpLogDepth() {
if lastLog.timeIntervalSinceNow < -1.0 {
logPrefix += "__"
lastLog = NSDate()
}
}
// we haven't covered extensions as yet
// but it's basically a way to add methods to a given class
extension FaceViewController
{
func logVCL(msg: String) {
bumpLogDepth()
print("\(logPrefix)Face \(instance) " + msg) //error: use of unresolved identifier 'instance'
}
override func awakeFromNib() {
logVCL("awakeFromNib()")
}
override func viewDidLoad() {
super.viewDidLoad()
logVCL("viewDidLoad()")
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
logVCL("viewWillAppear(animated = \(animated))")
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
logVCL("viewDidAppear(animated = \(animated))")
}
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
logVCL("viewWillDisappear(animated = \(animated))")
}
override func viewDidDisappear(animated: Bool) {
super.viewDidDisappear(animated)
logVCL("viewDidDisappear(animated = \(animated))")
}
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
logVCL("viewWillLayoutSubviews() bounds.size = \(view.bounds.size)")
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
logVCL("viewDidLayoutSubviews() bounds.size = \(view.bounds.size)")
}
override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
super.viewWillTransitionToSize(size, withTransitionCoordinator: coordinator)
logVCL("viewWillTransitionToSize")
coordinator.animateAlongsideTransition({ (context: UIViewControllerTransitionCoordinatorContext!) -> Void in
self.logVCL("animatingAlongsideTransition")
}, completion: { context -> Void in
self.logVCL("doneAnimatingAlongsideTransition")
})
}
}
extension EmotionsViewController
{
func logVCL(msg: String) {
bumpLogDepth()
print("\(logPrefix)Emotions \(instance) " + msg) //error: use of unresolved identifier 'instance'
}
override func awakeFromNib() {
logVCL("awakeFromNib()")
}
override func viewDidLoad() {
super.viewDidLoad()
logVCL("viewDidLoad()")
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
logVCL("viewWillAppear(animated = \(animated))")
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
logVCL("viewDidAppear(animated = \(animated))")
}
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
logVCL("viewWillDisappear(animated = \(animated))")
}
override func viewDidDisappear(animated: Bool) {
super.viewDidDisappear(animated)
logVCL("viewDidDisappear(animated = \(animated))")
}
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
logVCL("viewWillLayoutSubviews() bounds.size = \(view.bounds.size)")
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
logVCL("viewDidLayoutSubviews() bounds.size = \(view.bounds.size)")
}
override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
super.viewWillTransitionToSize(size, withTransitionCoordinator: coordinator)
logVCL("viewWillTransitionToSize")
coordinator.animateAlongsideTransition({ (context: UIViewControllerTransitionCoordinatorContext!) -> Void in
self.logVCL("animatingAlongsideTransition")
}, completion: { context -> Void in
self.logVCL("doneAnimatingAlongsideTransition")
})
}
}
错误:"use of unresolved identifier 'instance'" 表示您正在尝试使用尚未声明的变量。
在您的情况下,EmotionsViewController
(EmotionsViewController.swift) and/or let instance = getFaceMVCinstanceCount()
FaceViewController
( FacialExpression.swift).
只需查看此处提供的完整资源: Lecture 6: Multiple MVCs
该错误意味着您正在尝试打印 instance
但您没有在任何地方的代码中定义它。两次检查您的代码,您的对象或变量是否带有 instance
标识符。
希望这会有所帮助:)