快速将AnyObject投射到字典 [英] Casting AnyObject to Dictionary in swift

问题描述

我正在使用AFNetworking从iTunes API获取数据，我想使用响应创建一个Dictionary，但是我做不到.

I'm getting data from iTunes API with AFNetworking and I want to create a Dictionary with the response but I can't do it.

错误:无法将表达式的类型字典"转换为类型哈希"

Error: Cannot convert the expression's type "Dictionary " to type "Hashable"

这是我的代码:

func getItunesStore() {

        self.manager.GET( "https://itunes.apple.com/es/rss/topfreeapplications/limit=10/json",
            parameters: nil,
            success: { (operation: AFHTTPRequestOperation!,responseObject: AnyObject!) in
                var jsonResult: Dictionary = responseObject as Dictionary

            },
            failure: { (operation: AFHTTPRequestOperation!,error: NSError!) in
                println("Error:" + error.localizedDescription)
            })

    }

推荐答案

在Swift中定义Dictionary时，还必须提供键和值类型.像这样:

When you define a Dictionary in Swift you have to give key and value types as well. Something like:

var jsonResult = responseObject as Dictionary<String, AnyObject>

但是，如果强制转换失败，则会出现运行时错误-最好使用以下内容:

If the cast fails, however, you'll get a runtime error -- you're better off with something like:

if let jsonResult = responseObject as? Dictionary<String, AnyObject> {
    // do whatever with jsonResult
}

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