Swift - 意外发现 nil [重复]

Question

执行以下代码时，Xcode 显示 nil 错误：

---

//
//  ViewController.swift
//  Menu
//
//  Created by Programmer on 8/1/17.
//  Copyright © 2017 Programmer. All rights reserved.
//

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var LeadingConstr1: NSLayoutConstraint!
    @IBOutlet weak var MenuView1: UIView!
    
    @IBOutlet weak var LeadingConstr2: NSLayoutConstraint!
    @IBOutlet weak var MenuView2: UIView!
    
    var menushowing1 = false;
    var menushowing2 = false;
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        
        MenuView1.layer.shadowOpacity = 1
        MenuView1.layer.shadowRadius = 6
        MenuView2.layer.shadowOpacity = 1
        MenuView2.layer.shadowRadius = 6
    }
    
    @IBAction func MenuBtn(_ sender: Any) {
        if (menushowing1) {
            LeadingConstr1.constant = -140
        }
        else {
            LeadingConstr1.constant = 0
            UIView.animate(withDuration: 0.3, animations: {
                self.view.layoutIfNeeded()
            })
            
            view.layoutIfNeeded()
        }
        
        menushowing1 = !menushowing1
    }
    
    @IBAction func MenuBtn2(_ sender: Any) {
        if (menushowing2) {
            LeadingConstr2.constant = -140
        }
        else {
            LeadingConstr2.constant = 0
            UIView.animate(withDuration: 0.3, animations: {
                self.view.layoutIfNeeded()
            })
            
            view.layoutIfNeeded()
        }
        
        menushowing2 = !menushowing2
    }
    
    
}

这是我收到的错误：

致命错误：在解包可选值时意外发现 nil 2017-08-03 07:18:40.647621-0400 菜单[383:53946] 致命错误： 解包可选值时意外发现 nil (lldb) –

Answer 1

您有一些与任何

Menu

无关的出口

@IBOutlet Menu

。从 XIB/Storyboard 中删除该连接或在视图控制器中添加变量。