Question

我创建了类，并编写了名为“ example”的单例函数

import UIKit

class example: NSObject {

class example {
    static let sharedInstance = example()
    var userInfo = (ID: "bobthedev", Password: 01036343984)
    // Networking: communicating server
    func network() {
        // get everything
    }
    private init() { }
}

}

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
    super.viewDidLoad()
    example.sharedInstance.userInfo
    // (ID "bobthedev", Password 01036343984)

    // ViewController One
    example.sharedInstance.userInfo.ID // "bobthedev"


}

但是我收到错误消息 *类型'example'没有成员'sharedInstance'*

https://learnswiftwithbob.com/course/object-oriented-swift/singleton-pattern.html

Answer 1

您创建了一个嵌套类。只需跳过内部声明：

import UIKit

class Example: NSObject {
    static let sharedInstance = Example()
    var userInfo = (ID: "bobthedev", Password: 01036343984)
    // Networking: communicating server
    func network() {
        // get everything
    }
    private override init() { }
}

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        Example.sharedInstance.userInfo
        // (ID "bobthedev", Password 01036343984)

        // ViewController One
        Example.sharedInstance.userInfo.ID // "bobthedev"

    }
}

Answer 2

您已经在示例中嵌入了示例类，因此在执行example.sharedInstance时，它是外部的，因此只需删除外部示例类即可。

Answer 3

类名应以大写字母开头。无需在类内部声明类，而需要为单例声明变量，请检查以下代码。

class Example {
    class var sharedInstance: Example {
            struct Singleton {
                static let instance = Example()
            }
            return Singleton.instance
        }
    var userInfo = (ID: "bobthedev", Password: 01036343984)
    // Networking: communicating server
    func network() {
        // get everything
    }
    private init() { }
}






class ViewController: UIViewController {
    override func viewDidLoad() {
    super.viewDidLoad()
    Example.sharedInstance.userInfo
    // (ID "bobthedev", Password 01036343984)

    // ViewController One
    example.sharedInstance.userInfo.ID // "bobthedev"


}

类型“ example”没有成员“ sharedInstance”

3 个答案: