swift - 如何在 Swift 3 中更新字典的键

Question

if (userFollowingArray[indexPath.row]["watcher_following"] as! Bool) == false {
    let dict : NSMutableDictionary = userFollowingArray[indexPath.row] as! NSMutableDictionary
    print(dict)
    dict["watcher_following"] = 1
    self.userFollowingArray[indexPath.row] = dict as! Dictionary<String, Any>
}

我想用 true/false 更新 watcher_following 键，但它抛出异常。

[_TtGCs26_SwiftDeferredNSDictionarySSP__ _swift_setObject:forKeyedSubscript:]: unrecognized selector sent to instance

Answer 1

不要在 Swift 中使用 NSMutable... 集合类型

• 将 userFollowingArray 声明为 Swift 数组

  var userFollowingArray = [[String:Any]]()
  

• 获取 Dictionary 作为 variable

  var dict = userFollowingArray[indexPath.row]
  

• 检查值

  if dict["watcher_following"] as! Bool == false {
  

• 如有必要，更新它并将字典分配回数组。

      dict["watcher_following"] = true
      userFollowingArray[indexPath.row] = dict
  }
  

  由于值语义，最后一步是必要的

使用自定义结构或类比使用字典要方便得多。