Ios 如何将switch case与UIViewController作为swift 2中的输入进行比较

我在swift的旧版本中有一些代码，比如贝娄

let initVc:UIViewController? = self.initViewController!
        switch initVc {
            case let vc as ProductListViewController:
                pageMenu?.moveToPage(0)
            case let vc as OrderListViewController:
                pageMenu?.moveToPage(1)
            case let vc as CustomerListViewController:
                pageMenu?.moveToPage(2)
            default:
                pageMenu?.moveToPage(0)
        }

Immutable value 'vc' was never used; consider replacing with '_' or removing it

在上面的代码中，initViewController是父视图控制器，从那里推送此控制器

更新到swift 2.0后会出现错误，如下面所示

let initVc:UIViewController? = self.initViewController!
        switch initVc {
            case let vc as ProductListViewController:
                pageMenu?.moveToPage(0)
            case let vc as OrderListViewController:
                pageMenu?.moveToPage(1)
            case let vc as CustomerListViewController:
                pageMenu?.moveToPage(2)
            default:
                pageMenu?.moveToPage(0)
        }

Immutable value 'vc' was never used; consider replacing with '_' or removing it

---

请建议满足此要求所需的更改。

等效代码，无需为（未使用的）变量赋值 将是：

switch initVc {
    case is ProductListViewController:
        pageMenu?.moveToPage(0)
    case is OrderListViewController:
        pageMenu?.moveToPage(1)
    case is CustomerListViewController:
        pageMenu?.moveToPage(2)
    default:
        pageMenu?.moveToPage(0)
}

---

使用

是

等效代码，无需为（未使用的）变量赋值 将是：

switch initVc {
    case is ProductListViewController:
        pageMenu?.moveToPage(0)
    case is OrderListViewController:
        pageMenu?.moveToPage(1)
    case is CustomerListViewController:
        pageMenu?.moveToPage(2)
    default:
        pageMenu?.moveToPage(0)
}

---

使用

是

谢谢Martin…非常有用。谢谢Martin…非常有用。