ios - swift 3 错误 [_SwiftValue nsli_superitem]

Question

在 swift 3 转换后我一直收到这个错误。

'NSInvalidArgumentException', reason: '-[_SwiftValue nsli_superitem]: unrecognized selector sent to instance 0x600000a54820'

有问题的代码是这样的，它可以很好地与 swift 2 配合使用:

let views = ["newView": userLabel]
let widthConstraints = NSLayoutConstraint.constraints(withVisualFormat: "H:[newView(0)]", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: views)
userMainLabel.addConstraints(widthConstraints)

Answer 1

这是 swift 3 的问题，其中字典被视为 [String: UIView?]

解决方法是将类型指定为非可选

let views: [String: UIView] = ["newView": userLabel]