NSObject无法转换

Question

下面的代码行出现了错误。因为这是我刚刚从github下载的一个项目，https://github.com/HubSpot/BidHub-iOS，我不知道这些行在做什么。

  let one = NSMutableAttributedString(string: "BID\n", attributes: bidAttrs as [NSObject : AnyObject] as [NSObject : AnyObject] )
    one.appendAttributedString(NSMutableAttributedString(string: "$\(startAmount + incrementOne)", attributes: otherAttrs))
    plusOneButton.setAttributedTitle(one, forState: .Normal)

    let five = NSMutableAttributedString(string: "BID\n", attributes: bidAttrs as [NSObject : AnyObject] as [NSObject : AnyObject])
    five.appendAttributedString(NSMutableAttributedString(string: "$\(startAmount + incrementFive)", attributes: otherAttrs))
    plusFiveButton.setAttributedTitle(five, forState: .Normal)

    let ten = NSMutableAttributedString(string: "BID\n", attributes: bidAttrs as [NSObject : AnyObject] as [NSObject : AnyObject])
    ten.appendAttributedString(NSMutableAttributedString(string: "$\(startAmount + incrementTen)", attributes: otherAttrs))
    plusTenButton.setAttributedTitle(ten, forState: .Normal)

错误如下

/Users/David/Desktop/iOS_app/Bid-Hub-app/iOS-app/BidHub-iOS-master/AuctionApp/BiddingVC/BiddingViewController.swift:104:109: Cannot convert value of type '[NSObject : AnyObject]' to expected argument type '[String : AnyObject]?'
/Users/DAVID/Desktop/iOS_app/Bid-Hub-app/iOS-app/BidHub-iOS-master/AuctionApp/BiddingVC/BiddingViewController.swift:112:109: Cannot convert value of type '[NSObject : AnyObject]' to expected argument type '[String : AnyObject]?'
/Users/DAVID/Desktop/iOS_app/Bid-Hub-app/iOS-app/BidHub-iOS-master/AuctionApp/BiddingVC/BiddingViewController.swift:108:110: Cannot convert value of type '[NSObject : AnyObject]' to expected argument type '[String : AnyObject]?'

所以就在你建议我把多余的

as [NSObject : AnyObject]

已经尝试过了，它会给出以下错误

/Users/David/Desktop/iOS_app/Bid-Hub-app/iOS-app/BidHub-iOS-master/AuctionApp/BiddingVC/BiddingViewController.swift:104:74: 'NSDictionary' is not implicitly convertible to '[NSObject : AnyObject]'; did you mean to use 'as' to explicitly convert?

编辑：

var bidAttrs = [NSFontAttributeName : UIFont(name: "Avenir-Light", size: 14.0)! , NSForegroundColorAttributeName: UIColor.grayColor()] as NSDictionary

Answer 1

您不需要将bidAttrs转换为NSDictionary，所以只需这样做：

var bidAttrs = [NSFontAttributeName : UIFont(name: "Avenir-Light", size: 14.0)! , NSForegroundColorAttributeName: UIColor.grayColor()]
let one = NSMutableAttributedString(string: "BID\n", attributes: bidAttrs )

但是，如果出于某种原因需要它成为一个NSDictionary，那么您的转换应该如下所示：

let one = NSMutableAttributedString(string: "BID\n", attributes: bidAttrs as? [String : AnyObject] )