Question

当我尝试编译此代码时：

GKPlayer.loadPlayersForIdentifiers(idsArray as [AnyObject] as [AnyObject], withCompletionHandler: { (players, error) -> Void in

我收到此错误：

无法转换类型＆＃39; [AnyObject]＆＃39;的值预期参数类型＆＃39; [String]＆＃39;在这一行：
  def extension_white_list
    %w(jpg jpeg gif png) if model.avatar.file.extension.present?
  end

我做错了什么？

Answer 1

尝试以下方法：

将var idsArray = NSMutableArray()替换为var idsArray = [String]()。这样就可以使用Swift数组，而不是Obj-C NSArray s。
然后替换：

GKPlayer.loadPlayersForIdentifiers(idsArray as [AnyObject] as [AnyObject], withCompletionHandler: { (players, error) -> Void in if (error != nil) {

使用：

GKPlayer.loadPlayersForIdentifiers(idsArray as [String], withCompletionHandler: { (players, error) -> Void in if (error != nil) {

Answer 2

与此问题非常相似： Problems with code when updating to Swift 2.0. “Cannot convert value..”

如您所知，您需要将[String]传递给loadPlayersForIdentifiers(_:withCompletionHandler:)的第一个参数。而且playerId!肯定是String。为什么你NSMutableArray知道这个？

将idsArray的声明更改为：

    var idsArray: [String] = []

导致错误的行：

    GKPlayer.loadPlayersForIdentifiers(idsArray, withCompletionHandler: { (players, error) -> Void in

Answer 3

尝试将idArray声明为Array<String>()而不是NSMutableArray()。

像这样：

// Loading ID from players connected in the match
    var idsArray = Array<String>()
    if (match != nil) {
        for players in match!.players {
            if let player = players as? GKPlayer {
                idsArray.append(player.playerID!)
            }
        }

    }

    GKPlayer.loadPlayersForIdentifiers(idsArray, withCompletionHandler: { (players, error) -> Void in
        if (error != nil) {
            // Handle error here
         ...
}
    })

无法转换类型＆＃39; [AnyObject]＆＃39;的值预期参数类型＆＃39; [String]＆＃39;

3 个答案: