Swift中的错误：（键：AnyObject，值：AnyObject）'无法转换为'NSDictionary'

Question

我遇到一个错误：错误：（键：AnyObject，值：AnyObject）'无法转换为'NSDictionary'。 请帮我解决问题，我尝试了其他解决方案，但未成功。

func getLastDayRatesData() -> NSDictionary? {
    if var rates = getRatesDataFromPlist() {
        if let lastUpdated = rates["last_updated"] as? NSDate{
            let ratesWithoutDate: NSMutableDictionary = rates as! NSMutableDictionary
            var sortedByDateRates = sorted(ratesWithoutDate) {($0.0 as! String) > ($1.0 as! String)}
            if let latestRates = sortedByDateRates.first {
                return latestRates // Error: (key: AnyObject, value: AnyObject)' is not convertible to 'NSDictionary'
            }
        }
    }
    return nil
}

Answer 1

刚刚将代码更改为

func getLastDayRatesData() ->  (AnyObject, AnyObject)?

一切都很好。