Swift如何使用Alamofire将字符串数组参数写入请求的httpBody

• 常规接口请求通常使用字典作为请求参数，但当前对接的删除照片API要求请求体仅传入包含图片URL字符串的数组
• 示例请求头及请求体如下：

Content-Type: application/json; charset=UTF-8
Content-Length: 80
Authorization: Bearer [token]
["https://work-solution.s3.eu-north-1.amazonaws.com/job-83-image-gpfv7dfy.jpeg"]

目前已经通过Alamofire实现了将单个String写入httpBody的方法，代码如下：

struct BodyStringEncoding: ParameterEncoding {

    private let body: String

    init(body: String) { self.body = body }

    func encode(_ urlRequest: URLRequestConvertible, with parameters: Parameters?) throws -> URLRequest {
        guard var urlRequest = urlRequest.urlRequest else { throw Errors.emptyURLRequest }
        guard let data = body.data(using: .utf8) else { throw Errors.encodingProblem }
        urlRequest.httpBody = data
        return urlRequest
    }
}

调整现有实现，让请求体为字符串数组而非纯字符串。

有两种常用实现方式，按需选择即可：

方式一：修改Encoding实现，直接支持传入字符串数组（推荐，避免手动拼接JSON的转义错误） #

struct BodyStringArrayEncoding: ParameterEncoding {
    private let stringArray: [String]

    init(stringArray: [String]) { self.stringArray = stringArray }

    func encode(_ urlRequest: URLRequestConvertible, with parameters: Parameters?) throws -> URLRequest {
        guard var urlRequest = urlRequest.urlRequest else { throw Errors.emptyURLRequest }
        // 直接把数组序列化为JSON数据
        let data = try JSONSerialization.data(withJSONObject: stringArray, options: [])
        urlRequest.httpBody = data
        // 自动补全Content-Type，避免手动设置遗漏
        if urlRequest.value(forHTTPHeaderField: "Content-Type") == nil {
            urlRequest.setValue("application/json; charset=UTF-8", forHTTPHeaderField: "Content-Type")
        }
        return urlRequest
    }
}

使用示例 #

let imageUrls = ["https://work-solution.s3.eu-north-1.amazonaws.com/job-83-image-gpfv7dfy.jpeg"]
AF.request(deleteUrl, method: .delete, encoding: BodyStringArrayEncoding(stringArray: imageUrls))
    .response { response in
    // 处理响应逻辑
}

方式二：不修改现有Encoding，手动把数组转成JSON字符串传入 #

如果你不想新增Encoding结构体，也可以直接把数组转成JSON字符串后复用现有BodyStringEncoding：

let imageUrls = ["https://work-solution.s3.eu-north-1.amazonaws.com/job-83-image-gpfv7dfy.jpeg"]
let jsonData = try JSONSerialization.data(withJSONObject: imageUrls, options: [])
let jsonString = String(data: jsonData, encoding: .utf8) ?? ""

AF.request(deleteUrl, method: .delete, encoding: BodyStringEncoding(body: jsonString))
    .response { response in
    // 处理响应逻辑
}

内容的提问来源于stack exchange，提问作者Lukasz D