Swift中的Alamofire:在可用的JSON字典中转换响应数据 [英] Alamofire in Swift: converting response data in usable JSON dictionary

问题描述

我想处理一个JSON字符串，该字符串是使用 Alamofire 进行的HTTP调用作为数据返回的.

I would like to handle a JSON string that is returned as data from a HTTP call made using Alamofire.

此问题使用但是我想稍微低一点"，并了解如何将响应对象转换为字典.

However I wanted to go a little bit "lower level" and understand how to convert the response object into a dictionary.

推理是，感觉字典可能是访问响应中JSON值的简单方法(而不是必须经历将响应转换为JSON对象的过程).

Reasoning is that it feels that a dictionary may be a simple / easy way to access to the JSON values in the response (rather than having to go through the process of converting the response to a JSON object).

这是基于JSON对象和字典是同一件事(是吗?)的假设.

This is under the assumption that JSON objects and dictionaries are the same thing (are they?).

这是我编写的示例函数:

Here is the sample function that I wrote:

func question() -> Void{
    let response : DataRequest = Alamofire.request("http://aapiurl", parameters: nil)

    // Working with JSON Apple developer guide:
    // https://developer.apple.com/swift/blog/?id=37

    response.responseJSON { response in
        if let JSON  = response.result.value
        {

            print("JSON: \(JSON)") // Works!

            let data  = JSON as! NSMutableDictionary
            // Casting fails
            // Could not cast value of type '__NSCFArray' (0x19f952150) to 'NSMutableDictionary' (0x19f9523f8).
            print("Data: \(data)")
        }
    }
}

JSON对象似乎是Any类型，并且没有以下答案中建议的任何方法.

The JSON object seems to be of type Any and does not have any of the methods that are suggested in the answers below.

我尝试将其转换为字典，并出现以下错误:

I have tried to convert it to a Dictionary and got the error below:

推荐答案

Alamofire的结果值类型为Any，因为它通常是数组或字典.在Swift中，通常不应使用NS *类，而应使用本机swift类型，例如Array和Dictionary.

Alamofire has the result value of type Any because it usually would be an array or a dictionary. In Swift you normally shouldn't use NS* classes, but rather native swift types such as Array and Dictionary.

您可以(应该)使用可选参数来查看返回的JSON对象:

You can (should) use optionals to look into the returned JSON object:

if let array = response.result.value as? [Any] {
    print("Got an array with \(array.count) objects")
}
else if let dictionary = response.result.value as? [AnyHashable: Any] {
    print("Got a dictionary: \(dictionary)")
}
...

根据您对后端的期望，可以将每种情况视为成功还是失败.

Depending on what you expect from your backend, you can treat each of the cases as a success or a failure.

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