从 api 返回的数据总是 nil？

Question

我正在从 API 中检索数据。问题是数据总是 returns 为零。它是一个问题列表，通常是 10 个。我写的代码总是 returns 10 个 nil 结果。我用具有相同结构的不同 API 尝试了相同的代码，它总是有效。

这是结构：

struct Questions: Codable{
    let question: String?
}

这是代码：

guard let url = URL(string: "http://adminsapi.somee.com/Api/Test/?id=1") else { return }
    URLSession.shared.dataTask(with: url) { (data, response, error) in
        guard let data = data else { return }
        do{
            let test = try? JSONDecoder().decode([Questions].self, from: data)
            for ask in test{
                print(ask.question)
            }
        }
    }.resume()

这是我得到的结果：

nil nil nil nil nil nil nil nil nil nil

这是postman中API返回的数据：

[
    {
        "AskName": "Urgenct of defecation"
    },
    {
        "AskName": "Mucous and streaked stools"
    },
    {
        "AskName": "vomiting"
    },
    {
        "AskName": "Fever"
    },
    {
        "AskName": "Tympany on percussion"
    },
    {
        "AskName": "Bowel sounds"
    },
    {
        "AskName": "shifting dullness"
    },
    {
        "AskName": "psoas and obturator sign"
    },
    {
        "AskName": "rebound tenderness"
    },
    {
        "AskName": "signs of shock"
    }
]

此外，当我尝试解析 json 并读取一个字符串中的全部数据时，它完全可以正常工作。不知道问题出在哪里

Answer 1

已编辑。您的问题结构不正确。这是正确解析结果的工作操场代码。

import UIKit
import PlaygroundSupport

let data = """
[
    {
        "AskName": "Urgenct of defecation"
    },
    {
        "AskName": "Mucous and streaked stools"
    },
    {
        "AskName": "vomiting"
    },
    {
        "AskName": "Fever"
    },
    {
        "AskName": "Tympany on percussion"
    },
    {
        "AskName": "Bowel sounds"
    },
    {
        "AskName": "shifting dullness"
    },
    {
        "AskName": "psoas and obturator sign"
    },
    {
        "AskName": "rebound tenderness"
    },
    {
        "AskName": "signs of shock"
    }
]
""".data(using: .utf8)!

struct Questions: Codable{
    let AskName:String
}

do {
    try JSONDecoder().decode([Questions].self, from: data)
} catch {
    print(error)
}

您也可以定义为：

struct Questions: Codable {
    let question: String

    private enum CodingKeys: String, CodingKey {
        case question = "AskName"
    }
}

Answer 2

您的 Question 实施是错误的。您需要告诉编译器 question 变量需要使用 AskName 键进行解码。

struct Questions: Codable {
    let question: String?

    private enum CodingKeys: String, CodingKey {
        case question = "AskName"
    }
}

从 api 返回的数据总是 nil？

The data returned from the api is always nil?

api

httprequest

swift

urlsession