将 Xcode 更新为 7.0 后出错

Question

我正在 Swift 开发一个 iOS 应用程序。 当我将 Xcode 更新到 7.0 时，我在 swiftyJSON 中遇到错误。

 static func fromObject(object: AnyObject) -> JSONValue? {
    switch object {
    case let value as NSString:
        return JSONValue.JSONString(value as String)
    case let value as NSNumber:
        return JSONValue.JSONNumber(value)
    case let value as NSNull:
        return JSONValue.JSONNull
    case let value as NSDictionary:
        var jsonObject: [String:JSONValue] = [:]
        for (k:AnyObject, v:AnyObject) in value {// **THIS LINE- error: "Definition conflicts with previous value"**
            if let k = k as? NSString {
                if let v = JSONValue.fromObject(v) {
                    jsonObject[k] = v
                } else {
                    return nil
                }
            }
        }

有什么问题吗？你能帮忙吗？

Answer 1

 for (k:AnyObject, v:AnyObject) in value { .. }

必须写成Swift2如

for (k, v) : (AnyObject, AnyObject) in value { .. }

来自 Xcode 7 发行说明：

Type annotations are no longer allowed in patterns and are considered part of the outlying declaration. This means that code previously written as:

var (a : Int, b : Float) = foo()

needs to be written as:

var (a,b) : (Int, Float) = foo()

if an explicit type annotation is needed. The former syntax was ambiguous with tuple element labels.

但在您的情况下，实际上根本不需要显式注释：

for (k, v) in value { .. }

因为NSDictionary.Generator已经定义为生成器 返回 (key: AnyObject, value: AnyObject) 个元素。