从AnyObject（NSString）获取String [英] Get from AnyObject(NSString) to String

问题描述

我正在读一个plist键（带有n个NSDictionaries的NSArray）：

I am reading a plist key (NSArray with n NSDictionaries):

    let regionsToMonitor = NSBundle.mainBundle().infoDictionary["Regions"] as Array<Dictionary<String,AnyObject>>

现在我迭代它：

    for regionToMonitor in regionsToMonitor {

现在我想获得ObjC中regionToMonitor的uuidString

and now I want to to get uuidString of the regionToMonitor

： NSString * uuidString = regionToMonitor [@uuidString];

在swift中我尝试：让uuidString = regionToMonitor [uuid]！。stringValue;

in swift I try: let uuidString = regionToMonitor["uuid"]!.stringValue;

以上编译但是字符串在swift中总是 nil 。 regionToMonitor [uuid] 在没有！.stringValue的情况下使用 println

the above does compile but the string is always nil in swift. regionToMonitor["uuid"] when used without !.stringValue works fine in println

如何在这里获得有效的Swift.String？

how do I get a valid Swift.String here?

我试图将其传递给NSUUID！

我也试过

让uuidString：String = regionToMonitor [uuid]

=> AnyObject不能转换为String

let uuidString:String = regionToMonitor["uuid"]
=> AnyObject isn't convertible to String

让uuidString = regionToMonitor [uuid] as String

=>找不到接受提供参数的'subscript'的重载

let uuidString = regionToMonitor["uuid"] as String
=> Could not find an overload for 'subscript' that accepts the supplied arguments

让uuidString = regionToMonitor [uuid];

=>'AnyObject？'不能被隐含地转向'String';你的意思是使用'as'强制向下倾斜？

let uuidString = regionToMonitor["uuid"];
=> 'AnyObject?' cannot be implicitly downcast to 'String'; did you mean to use 'as' to force downcast?

推荐答案

我最终得到了丑陋的一句话：

I ended up with the ugly line:

var uuidString:String = regionToMonitor["uuid"] as! String

没有警告，没有错误，没有运行时错误

no warnings, no errors, no runtime error

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