如何在按钮单击时从另一个类调用函数

Question

我已经以编程方式创建了一组按钮，但是当我从外部类触发按钮触发视图上的函数时，所有当前变量引用都在我的视图中消失并导致错误，表示存在意外的可选项。任何静态数据和逻辑仍可正常加载。如果我检查选项，程序会停止错误，因此由于某种原因删除了引用。我的构建按钮的类

class CategoryButton: NSObject{
    func createButton(category: Category, index: Int) -> CategoryButton.Button{
        let button =  CategoryButton.Button(frame: .zero, category: category)
        button.titleEdgeInsets = UIEdgeInsetsMake(10, 10, 10, 10)
        button.setTitle(category.name, forState: .Normal)
        button.setTitleColor(UIColor.whiteColor(), forState: .Normal)
        button.titleLabel?.font = UIFont(name: "Helvetica-bold", size: 17.0)
        button.titleLabel?.numberOfLines = 2
        button.titleLabel?.textAlignment = .Center
        button.setBackgroundImage(UIImage(named: "category-box.png"), forState: .Normal)
        button.frame = CGRectMake(CGFloat(index * (130 + 8)), 15 , 130, 106)
        button.addTarget(button, action: #selector(button.categoryClicked(_:)), forControlEvents: UIControlEvents.TouchUpInside)
        return button
    }

    class Button: UIButton{
        var category: Category?

        init(frame: CGRect, category: Category) {
            self.category = category

            super.init(frame: frame)
        }

        required init?(coder aDecoder: NSCoder) {
            super.init(coder: aDecoder)
        }

        func categoryClicked(sender: CategoryButton.Button){
            if let c = sender.category{
                Workstation.instance.currentCategory = c
                let dashboard = DashboardViewController()
                dashboard.loadCategories()
            }
        }
    }

    class var instance: CategoryButton{
        struct Static {
            static let instance = CategoryButton()
        }
        return Static.instance
    }
}

在我的视图中，我正在调用使用

创建按钮

func loadCategories(){
        var currentCategoryButtons: [CategoryButton.Button] = []

        var addedCount = 0

        for category in Workstation.instance.categories{
            if let currentCategory = Workstation.instance.currentCategory{
                print("\(currentCategory.name) \(category.name)")
                print("\(currentCategory.id) \(category.parentCategoryId)")
                if currentCategory.id == category.parentCategoryId{
                    let button = CategoryButton.instance.createButton(category, index: addedCount)
                    if let container = self.categoryContainer{
                        currentCategoryButtons.append(button)
                        container.addSubview(button)
                        addedCount += 1
                    }
                }
            }else{
                if category.parentCategoryId.characters.count <= 0{
                    let button: CategoryButton.Button = CategoryButton.instance.createButton(category, index: addedCount)
                    currentCategoryButtons.append(button)
                    self.categoryContainer.addSubview(button)
                    addedCount += 1
                }
            }
        }

        if let container = self.categoryContainer{
            container.contentSize = CGSizeMake(CGFloat(addedCount * (130 + 8)), 131)
            container.contentInset = UIEdgeInsetsMake(0, 20, 0, 0)
            container.setContentOffset(CGPoint(x: -15, y: 0), animated: true)
        }
    }