Ios 在 Swift 中上传带参数的图像

在您下面的 comments 中，您告知我们您正在使用$_FILES语法检索文件.这意味着您要创建一个multipart/form-data请求.这个过程基本上是:

1. 为您的multipart/form-data请求指定边界.

2. 指定请求的Content-Type，该请求指定它是multipart/form-data以及边界是什么.

3. 创建请求主体，分离各个组件(每个发布的值以及每个上传之间的值).

有关更多详细信息，请参见RFC 7578.无论如何，在SWIFT 3和更高版本中，这可能类似于:

/// Create request
///
/// - parameter userid:   The userid to be passed to web service
/// - parameter password: The password to be passed to web service
/// - parameter email:    The email address to be passed to web service
///
/// - returns:            The `URLRequest` that was created

func createRequest(userid: String, password: String, email: String) throws -> URLRequest {
    let parameters = [
        "user_id"  : userid,
        "email"    : email,
        "password" : password]  // build your dictionary however appropriate
    
    let boundary = generateBoundaryString()
    
    let url = URL(string: "https://example.com/imageupload.php")!
    var request = URLRequest(url: url)
    request.httpMethod = "POST"
    request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")
    
    let fileURL = Bundle.main.url(forResource: "image1", withExtension: "png")!
    request.httpBody = try createBody(with: parameters, filePathKey: "file", urls: [fileURL], boundary: boundary)
    
    return request
}

/// Create body of the `multipart/form-data` request
///
/// - parameter parameters:   The optional dictionary containing keys and values to be passed to web service.
/// - parameter filePathKey:  The optional field name to be used when uploading files. If you supply paths, you must supply filePathKey, too.
/// - parameter urls:         The optional array of file URLs of the files to be uploaded.
/// - parameter boundary:     The `multipart/form-data` boundary.
///
/// - returns:                The `Data` of the body of the request.

private func createBody(with parameters: [String: String]? = nil, filePathKey: String, urls: [URL], boundary: String) throws -> Data {
    var body = Data()
    
    parameters?.forEach { (key, value) in
        body.append("--\(boundary)\r\n")
        body.append("Content-Disposition: form-data; name=\"\(key)\"\r\n\r\n")
        body.append("\(value)\r\n")
    }
    
    for url in urls {
        let filename = url.lastPathComponent
        let data = try Data(contentsOf: url)
        
        body.append("--\(boundary)\r\n")
        body.append("Content-Disposition: form-data; name=\"\(filePathKey)\"; filename=\"\(filename)\"\r\n")
        body.append("Content-Type: \(url.mimeType)\r\n\r\n")
        body.append(data)
        body.append("\r\n")
    }
    
    body.append("--\(boundary)--\r\n")
    return body
}

/// Create boundary string for multipart/form-data request
///
/// - returns:            The boundary string that consists of "Boundary-" followed by a UUID string.

private func generateBoundaryString() -> String {
    return "Boundary-\(UUID().uuidString)"
}

使用:

extension URL {
    /// Mime type for the URL
    ///
    /// Requires `import UniformTypeIdentifiers` for iOS 14 solution.
    /// Requires `import MobileCoreServices` for pre-iOS 14 solution

    var mimeType: String {
        if #available(iOS 14.0, *) {
            return UTType(filenameExtension: pathExtension)?.preferredMIMEType ?? "application/octet-stream"
        } else {
            guard
                let identifier = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, pathExtension as CFString, nil)?.takeRetainedValue(),
                let mimeType = UTTypeCopyPreferredTagWithClass(identifier, kUTTagClassMIMEType)?.takeRetainedValue() as String?
            else {
                return "application/octet-stream"
            }

            return mimeType
        }
    }
}

extension Data {
    
    /// Append string to Data
    ///
    /// Rather than littering my code with calls to `data(using: .utf8)` to convert `String` values to `Data`, this wraps it in a nice convenient little extension to Data. This defaults to converting using UTF-8.
    ///
    /// - parameter string:       The string to be added to the `Data`.
    
    mutating func append(_ string: String, using encoding: String.Encoding = .utf8) {
        if let data = string.data(using: encoding) {
            append(data)
        }
    }
}

有了所有这些，您现在需要提交此请求.我建议这是异步完成的.例如，使用URLSession，您将执行如下操作:

let request: URLRequest

do {
    request = try createRequest(userid: userid, password: password, email: email)
} catch {
    print(error)
    return
}

let task = URLSession.shared.dataTask(with: request) { data, response, error in
    guard let data = data, error == nil else {
        // handle error here
        print(error ?? "Unknown error")
        return
    }
    
    // parse `data` here, then parse it
    
    // note, if you want to update the UI, make sure to dispatch that to the main queue, e.g.:
    //
    // DispatchQueue.main.async {
    //     // update your UI and model objects here
    // }
}
task.resume()

如果您上传的是大型assets资源 (例如视频等)，则可能需要使用上述内容的基于文件的排列.请参见https://stackoverflow.com/a/70552269/1271826.

有关Swift 2格式副本，请参见previous revision of this answer.