从 swift 中的字典中检索字典数组

Question

我有一个 json 响应，其中包含一个字典数组。我希望能够将该数组复制到现有数组中。

我在 Objective-C 中的做法是这样的：

dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    dispatch_async(queue, ^{
        NSError *error = nil;
        NSDictionary *responseDictionary = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];
        NSArray *venuesArray = responseDictionary[@"response"][@"venues"];

        completion(venuesArray, error);
    });

在swift中它必须是这样的：

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), {
                var error: NSError?
                let responseDictionary: Dictionary<String, AnyObject> = NSJSONSerialization.JSONObjectWithData(data, options: nil, error: &error) as Dictionary
                let venuesArray : AnyObject[] = (responseDictionary as AnyObject).valueForKeyPath("response.venues")
                completionClosure(venues: responseDictionary, error: error);
            });

但这给了我以下错误：

'AnyObject' is not convertible to 'AnyObject[]'

任何帮助将不胜感激！

Answer 1

问题在于你声明AnyObject[]： 错误（'AnyObject' is not convertible to 'AnyObject[]'）明确指出，没有数组初始化。

如果初始化器应该是数组值然后用于AnyObject[]，请先检查响应值。

替换：

let venuesArray : AnyObject[] = (responseDictionary as AnyObject).valueForKeyPath("response.venues")

到

let venuesArray : AnyObject = (responseDictionary as AnyObject).valueForKeyPath("response.venues")