swift UserDefaults返回nil为NSMutableArray(swift UserDefaults return nil as NSMutableArray)

swift UserDefaults返回nil为NSMutableArray(swift UserDefaults return nil as NSMutableArray)

我有多行文本，我保存他们UserDefaults。 当我想得到文本有时返回零。 但是里面有一个文字。 我怎么能这样做，零没有回来？

var savedReports: NSMutableArray = NSMutableArray() if let sR = defaults.object(forKey: "savedReports") as? NSMutableArray { savedReports = sR.mutableCopy() as! NSMutableArray }

I have multi line texts and i save them UserDefaults. When i want to get the text sometimes return nil. But there is a text in it. How can i do that the nil does not return?

var savedReports: NSMutableArray = NSMutableArray() if let sR = defaults.object(forKey: "savedReports") as? NSMutableArray { savedReports = sR.mutableCopy() as! NSMutableArray }

最满意答案

UserDefaults API将始终返回不可UserDefaults 。 你要：

var savedReports: NSMutableArray = NSMutableArray() if let sR = defaults.object(forKey: "savedReports") as? NSArray { savedReports = sR.mutableCopy() }

The UserDefaults API will always return immutable arrays. You want:

var savedReports: NSMutableArray = NSMutableArray() if let sR = defaults.object(forKey: "savedReports") as? NSArray { savedReports = sR.mutableCopy() }