实例成员不能用于类型 - 错误

Question

我一直有一个奇怪的错误，并且在尝试修复它时没有运气。我有一些链接的文件，我正在一个文件(ViewController(中调用一个函数，该函数在另一个文件(Sign.swift(中定义。Sign.swift中的函数创建在另一个文件 (GameState.swift( 中定义的输出。我不确定这有什么问题，我做了很多研究，即使这个答案也没有帮助。(代码下的错误(。

ViewController.swift：

import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
@IBOutlet weak var computerLabel: UILabel!
@IBOutlet weak var output: UILabel!
@IBOutlet weak var rockButton: UIButton!
@IBOutlet weak var paperButton: UIButton!
@IBOutlet weak var scissorsButton: UIButton!
@IBOutlet weak var playAgain: UIButton!
@IBAction func rockButtonPressed(_ sender: UIButton) {
computerLabel.text = randomSign()
var playerChoice = Sign.rock
var output = Sign.checkInputs(playerChoice, computerLabel.text) //Error 1 is here
}
@IBAction func paperButtonPressed(_ sender: UIButton) {
}
@IBAction func scissorsButtonPressed(_ sender: UIButton) {
}
@IBAction func playAgainPressed(_ sender: UIButton) {
}

}

Sign.swift：

import Foundation
import GameplayKit
let randomChoice = GKRandomDistribution(lowestValue: 0, highestValue: 2)
func randomSign() -> String {
let sign = randomChoice.nextInt()
if sign == 0 {
return "👊"
}
else if sign == 1 {
return "🖐"
}
else {
return "✌️"
}
}
enum Sign {
case rock, paper, scissors
var emoji: String {
switch self {
case .rock:
return "👊"
case.paper:
return "🖐"
case.scissors:
return "✌️"
}
}
func checkInputs(_ user: Sign, opponent: Sign) -> String {
var outcome = GameState.draw
if (opponent == .rock) {
if (emoji == "👊") {
outcome = .draw
}
else if (emoji == "🖐") {
outcome = .win
}
else {
outcome = .lose
}
}
else if (opponent == .paper) {
if (emoji == "👊") {
outcome = .lose
}
else if (emoji == "🖐") {
outcome = .draw
}
else {
outcome = .win
}
}
else if (opponent == .scissors) {
if (emoji == "👊") {
outcome = .win
}
else if (emoji == "🖐") {
outcome = .lose
}
else {
outcome = .draw
}
}
return outcome //Error 2 is here
}
}

GameState.swift：

import Foundation
enum GameState {
case start, win, lose, draw
var text: String {
switch self {
case.start:
return "Game started!"
case.win:
return "You win!"
case.lose:
return "You lose!"
case.draw:
return"It's a draw!"
}
}
}

我在两个文件中都收到错误：错误 1(ViewController.swift中的注释行(有以下错误消息：

实例成员"checkInputs"不能用于类型"符号";你是否 意思是改用这种类型的值？

不幸的是，我不明白我的意思是从上面的消息中修复什么，我是 Swift 的新手。

错误 2(Sign.swift中的注释行(有以下消息：

无法将类型为"游戏状态"的返回表达式转换为返回类型 "字符串">

再说一次，我不明白这里发生了什么。不过，我的GameState.swift文件中没有任何错误，因此这意味着所有错误都应该在ViewController.swift和Sign.swift中。我应该如何修复这些错误？

编辑：我已经更新了我的代码，现在看起来像这样：

ViewController.swift：

import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func computerChoose() {
}
@IBOutlet weak var computerLabel: UILabel!
@IBOutlet weak var output: UILabel!
@IBOutlet weak var rockButton: UIButton!
@IBOutlet weak var paperButton: UIButton!
@IBOutlet weak var scissorsButton: UIButton!
@IBOutlet weak var playAgain: UIButton!
@IBAction func rockButtonPressed(_ sender: UIButton) {
var random = randomSign()
var stringRandom = ""
switch random {
case .rock :
stringRandom = "👊"
case .paper:
stringRandom = "🖐"
case .scissors:
stringRandom = "✌️"
}
var playerChoice = Sign.rock
var output = Sign.checkInputs(random)
computerLabel.text = stringRandom
}
@IBAction func paperButtonPressed(_ sender: UIButton) {
}
@IBAction func scissorsButtonPressed(_ sender: UIButton) {
}
@IBAction func playAgainPressed(_ sender: UIButton) {
}

}

Sign.swift：

import Foundation
import GameplayKit
let randomChoice = GKRandomDistribution(lowestValue: 0, highestValue: 2)
func randomSign() -> Sign {
let sign = randomChoice.nextInt()
if sign == 0 {
return .rock
}
else if sign == 1 {
return .paper
}
else {
return .scissors
}
}
enum Sign {
case rock, paper, scissors
var emoji: String {
switch self {
case .rock:
return "👊"
case.paper:
return "🖐"
case.scissors:
return "✌️"
}
}
static func checkInputs(_ opponent: Sign) -> GameState {
var outcome = GameState.draw
if (opponent == .rock) {
if (emoji == "👊") { //Error Emoji
outcome = .draw
}
else if (emoji == "🖐") { //Error Emoji
outcome = .win
}
else {
outcome = .lose
}
}
else if (opponent == .paper) { //Error Emoji
if (emoji == "👊") {
outcome = .lose
}
else if (emoji == "🖐") { //Error Emoji
outcome = .draw
}
else {
outcome = .win
}
}
else if (opponent == .scissors) {
if (emoji == "👊") { //Error Emoji
outcome = .win
}
else if (emoji == "🖐") { //Error Emoji
outcome = .lose
}
else {
outcome = .draw
}
}
return outcome
}
}

注意：新错误出现在每行带有注释Error Emoji，并带有以下错误消息：

实例成员"表情符号"不能用于类型"符号">

GameState.swift：不变。

我将不胜感激所有帮助。

Answer 1

如果需要在没有实例的情况下使用该方法，则需要将该方法声明为static。

static func checkInputs(_ user: Sign, opponent: Sign) -> String

注意：您似乎没有使用您传递的user。 IMO 您可以跳过对该参数的请求，并将其用作具有playerChoice的实例方法。

func checkInputs(opponent: Sign) -> String {
// Your logic
}

然后像这样使用它

playerChoice.checkInputs(opponent: randomSign())

第二个错误是因为您尝试返回Sign的实例而不是String。您需要将返回类型更改为Sign或将Signoutcome隐藏为String-outcome.text像@Larme指出的那样？