Swift：将字典转换为 JSON for multipart/Form-Data

Question

我有一个 swift 应用程序，它向服务器发出具有正常值和图像的请求，所以我使用 multipart/form-data 请求。我有一个包含我所有值的对象，如下所示：

 struct parameters: Codable {
     var request : String = "blah"
     var arrayData : [String] = ["bleh", "bluh"]
     var dictionaryData : [String: String] = ["1": "Blah", "2": "Blah"]
 }

但是，我无法将数组和字典的 json 转换版本插入到 httpBody 中。我试过使用 JSONEncoder()，但它会将整个对象转换为 JSON，而且我无法插入边界和其他内容。有什么方法可以将数组和字典转换为 json 格式，然后我可以将其作为值插入 multipart/form-data 请求中。

例如，对于字符串、字典和数组，它将 return

 "blah"
 ["bleh", "bluh"]
 {"1": "Blah", "2": "Blah"}

Answer 1

let dictParam = NSMutableDictionary() //字典

var ids = [String]()
let cat = (Constants.app_delegate.dictAddPostInfo.object(forKey: "categoryArr") as! NSArray)

//filter id from dic and add in ids
for dic in cat {
    let dic = dic as! NSDictionary
    let id = dic["id"] as! Int
    ids.append(String(id))
}
//set data to dicParam
for i in 0..<ids.count {
    let key = String.init(format: "categories[%d]", i)
    dictParam.setValue(ids[i], forKey: key)
}


//For single value 
dictParam.setValue(Constants.app_delegate.dictAddPostInfo.object(forKey: "Title") as! String, forKey: "title")
dictParam.setValue(Constants.app_delegate.dictAddPostInfo.object(forKey: "Description") as! String, forKey: "description")
dictParam.setValue(Constants.app_delegate.dictAddPostInfo.object(forKey: "Price") as! String, forKey: "price")
dictParam.setValue(latitude, forKey: "latitude")
dictParam.setValue(longitude, forKey: "longitude")

if let area = Constants.app_delegate.dictAddPostInfo.object(forKey: "area") as? String {
    dictParam.setValue(area, forKey: "area")
}
else {
    dictParam.setValue("", forKey: "area")
}

if let city = Constants.app_delegate.dictAddPostInfo.object(forKey: "city") as? String {
    dictParam.setValue(city, forKey: "city")
}
else {
    dictParam.setValue("", forKey: "city")
}


if let state = Constants.app_delegate.dictAddPostInfo.object(forKey: "state") as? String {
    dictParam.setValue(state, forKey: "state")
}
else {
    dictParam.setValue("", forKey: "state")
}


if let zip = Constants.app_delegate.dictAddPostInfo.object(forKey: "zip") as? String {
    dictParam.setValue(zip, forKey: "zip")
}
else {
    dictParam.setValue("", forKey: "zip")
}

这里是字典转换成json

的代码

   if let jsonData =  try? JSONSerialization.data(withJSONObject: dictParam, options: .prettyPrinted), let theJSONText = String(data: jsonData, encoding: .ascii) {
        print(theJSONText)
    }

Answer 2

您可以只对单独的组件进行编码，而不是对整个结构进行编码。使用上面的例子：

let paramters = Parameters()
let encoder = JSONEncoder()
encoder.outputFormatting = .prettyPrinted
let request = try! encoder.encode(paramters.request)
let array = try! encoder.encode(paramters.arrayData)
let dict = try! encoder.encode(paramters.dictionaryData)

这将单独为您提供组件，然后您可以访问它们并根据需要使用它们。作为一个简单的例子：

print("Request \n", String(data: request, encoding: .utf8)!, "\n\n")
print("Array \n", String(data: array,encoding: .utf8)!, "\n\n")
print("Dict \n", String(data: dict ,encoding: .utf8)!, "\n\n")

正在输出...

Request

"blah"

Array

[ "bleh", "bluh" ]

Dict

{ "2" : "Blah", "1" : "Blah" }

Swift：将字典转换为 JSON for multipart/Form-Data

Swift: Convert Dictionary into JSON for multipart/Form-Data

json

multipartform-data

swift