ios - 无法在Swift中设置IndexPath行

Question

以下代码会产生运行时错误，我不知道怎么办。有什么想法吗？

    var foo: IndexPath
    foo = IndexPath()
    foo.row = 1

    var i = 0

Answer 1

迅速有一个先决条件才能访问indexpath行

/// The section of this index path, when used with `UITableView`.
///
/// - precondition: The index path must have exactly two elements.
public var section: Int

/// The row of this index path, when used with `UITableView`.
///
/// - precondition: The index path must have exactly two elements.
public var row: Int

如果要访问或更改行，则需要使用行和节初始化indexPath

 var foo: IndexPath
 foo = IndexPath(row: 0, section: 0)
 foo.row = 1 // return foo (1,0)