Swift tuple switch case：类型的模式不能匹配类型的值[重复]

Question

因此，我正在为新工作学习 swift 并处理静态表格视图，并决定尝试使用元组来跟踪已选择的单元格。但是我收到以下错误：

'(section: Int, row: Int)'类型的表达式模式不能匹配'(section: Int, row: Int)'类型的值

此错误是以下简化代码的结果

    let ABOUTPROTECTIONCELL = (section: 1, row: 0)
    let cellIdentifier = (section: indexPath.section, row: indexPath.row)

    switch cellIdentifier {
    case ABOUTPROTECTIONCELL:
        print("here")
    default:
        print("bleh")
    }

真正令人困惑的是，当我使用以下“if”语句而不是 switch 语句时，一切正常，程序运行正常......

    if (cellIdentifier == CELL_ONE) {
        print("cell1")
    } else if (cellIdentifier == CELL_TWO) {
        print("cell2")
    } else if (cellIdentifier == CELL_THREE) {
        print("cell3")
    }

有没有办法用 switch 语句来做到这一点，因为我发现它比 if 语句更优雅？很好奇为什么这不起作用。提前致谢！

Answer 1

解决方案 1

let ABOUTTROVPROTECTIONCELL = (section: 1, row: 0)
let cellIdentifier = (section: indexPath.section, row: indexPath.row)

switch cellIdentifier {
case (ABOUTTROVPROTECTIONCELL.section, ABOUTTROVPROTECTIONCELL.row):
    print("here")
default:
    print("bleh")
}

解决方案 2

只需使用IndexPath 结构及其初始化器来创建ABOUTTROVPROTECTIONCELL

let ABOUTTROVPROTECTIONCELL = IndexPath(row: 0, section: 1)
let cellIdentifier = indexPath // Not necessary, you can just use indexPath instead

switch cellIdentifier {
case ABOUTTROVPROTECTIONCELL:
    print("here")
default:
    print("bleh")
}

解决方案 3

为您的元组实现~= func：

typealias IndexPathTuple = (section: Int, row: Int)
func ~=(a: IndexPathTuple, b: IndexPathTuple) -> Bool {
    return a.section ~= b.section && a.row ~= b.row
}

let ABOUTTROVPROTECTIONCELL = (section: 1, row: 0)
let cellIdentifier = (section: indexPath.section, row: indexPath.row)

switch cellIdentifier {
case ABOUTTROVPROTECTIONCELL:
    print("here")
default:
    print("bleh")
}