ios - 快速切换大小写警告

Question

我对 core-data 实体的 Int32 属性的切换条件为

switch location.userLocationLike?.likeStatusId {
            case 1 as Int32:
                view.lblLike.text = "LIKED"
            case 2 as Int32:
                view.lblLike.text = "OKAY"
            case 3 as Int32:
                view.lblLike.text = "DISLIKE"
            default:
                view.lblLike.text = "LIKE"
            }

如果我不将转换值输入为 Int32，则会显示错误，如果我将其转换为 Int32，则会显示警告。谁能解释一下编写 Switch-case 的最佳方法是什么。

Answer 1

该错误具有误导性，根据 as Int32 的警告，您无法在非可选情况下打开可选、可选绑定(bind)(甚至强制展开)userLocationLike > 强制转换毫无意义。

if let likeStatus = location.userLocationLike {

    switch likeStatus.likeStatusId {
        case 1: view.lblLike.text = "LIKED"
        case 2: view.lblLike.text = "OKAY"
        case 3  view.lblLike.text = "DISLIKE"
        default: view.lblLike.text = "LIKE"
    }
}