我如何从 swift4 中的字符串中获取特定的键值

Posted 2023-03-11

【中文标题】我如何从 swift4 中的字符串中获取特定的键值

【英文标题】：how do i get particular key value from string in swift4

【发布时间】：2017-11-29 09:43:20

【问题描述】：

我有来自 xml 的字符串响应，我得到了所有值，但我需要一个名为“District_NameEng”的特定键值我如何得到这个。

func parser(_ parser: XMLParser, foundCharacters string: String)

from "string"=我收到了这个回复

我的回答是：

["Loc_District":8119,"districtname":"अजमेर ","District_NameEng":"AJMER","Loc_District":8104,"districtname":"अलवर ","District_NameEng":"ALWAR","Loc_District":8125,"districtname":"बांसवाड़ा","District_NameEng":"BANSWARA","Loc_District":8128,"districtname":"बारां ","District_NameEng":"BARAN","Loc_District":8115,"districtname":"बाड़मेर ","District_NameEng":"BARMER","Loc_District":8105,"districtname":"भरतपुर ","District_NameEng":"BHARATPUR","Loc_District":8122,"districtname":"भीलवाडा ","District_NameEng":"BHILWARA","Loc_District":8101,"districtname":"बीकानेर ","District_NameEng":"BIKANER","Loc_District":8121,"districtname":"बून्दी ","District_NameEng":"BUNDI","Loc_District":8126,"districtname":"चित्तौड़गढ़ ","District_NameEng":"CHITTORGARH","Loc_District":8102,"districtname":"चूरू ","District_NameEng":"CHURU","Loc_District":8109,"districtname":"दौसा ","District_NameEng":"DAUSA","Loc_District":8106,"districtname":"धौलपुर ","District_NameEng":"DHOLPUR","Loc_District":8124,"districtname":"डूंगरपुर ","District_NameEng":"DUNGARPUR","Loc_District":8099,"districtname":"गंगानगर ","District_NameEng":"GANGANAGAR","Loc_District":8100,"districtname":"हनुमानगढ ","District_NameEng":"HANUMANGARH","Loc_District":8110,"districtname":"जयपुर ","District_NameEng":"JAIPUR","Loc_District":8114,"districtname":"जैसलमेर ","District_NameEng":"JAISALMER","Loc_District":8116,"districtname":"जालोर ","District_NameEng":"JALORE","Loc_District":8129,"districtname":"झालावाड ","District_NameEng":"JHALAWAR","Loc_District":8103,"districtname":"झुंझुंनु ","District_NameEng":"JHUNJHUNU","Loc_District":8113,"districtname":"जोधपुर ","District_NameEng":"JODHPUR","Loc_District":8107,"districtname":"करौली ","District_NameEng":"KAROULI","Loc_District":8127,"districtname":"कोटा ","District_NameEng":"KOTA","Loc_District":8112,"districtname":"नागौर ","District_NameEng":"NAGAUR","Loc_District":8118,"districtname":"पाली ","District_NameEng":"PALI","Loc_District":8131,"districtname":"प्रतापगढ ","District_NameEng":"PRATAPGARH","Loc_District":8123,"districtname":"राजसमन्द ","District_NameEng":"RAJSAMAND","Loc_District":8108,"districtname":"सवाई माधोपुर ","District_NameEng":"SAWAI MADHOPUR","Loc_District":8111,"districtname":"सीकर ","District_NameEng":"SIKAR","Loc_District":8117,"districtname":"सिरोही ","District_NameEng":"SIROHI","Loc_District":8120,"districtname":"टोंक ","District_NameEng":"TONK","Loc_District":8130,"districtname":"उदयपुर ","District_NameEng":"UDAIPUR"]

【问题讨论】：

那不是xml，那是JSON。使用JSONDecoder 和map

你试过什么？您当前的方法会导致什么问题？你有什么代码？。

@vadian 你能解释一下吗

【参考方案1】：

它是字典的 JSON 数组，您可以通过使用 map 和下面的数组来获取特定键的所有值。

let arrayValues = mainArray.map$0["District_NameEng"] as! String
print (arrayValues)

【讨论】：

Cannot subscript a value of type 'String' with a index of 'String' 显示此错误

我认为您将目标 c 和 swift 混合在一起。把你的代码放在你如何获得 mainArray

func parser(_ parser: XMLParser, foundCharacters string: String) 表单字符串我得到了我粘贴在我的问题中的所有值。现在告诉我如何将这个字符串更改为数组并获取值，正如你上面所说

首先您需要将 String 转换为 Array> 然后使用我的答案它会起作用

我对 swift 非常陌生 ..所以请告诉我如何将 String 转换为 Array>.i google 并获取 func convertToDictionary(text: String) -> [String ： 任何]？ if let data = text.data(using: .utf8) do return try JSONSerialization.jsonObject(with: data, options: []) as? [String: Any] catch print(error.localizedDescription) return nil 但它不起作用它显示。无法读取数据，因为它的格式不正确。

【参考方案2】：

以下是解析 json 字符串的示例代码

// I've escaped the double quotes so that it can run, you don't need to do it because you already have the string
let responseStr = "[\"Loc_District\":8119,\"districtname\":\"अजमेर \",\"District_NameEng\":\"AJMER\",\"Loc_District\":8104,\"districtname\":\"अलवर \",\"District_NameEng\":\"ALWAR\",\"Loc_District\":8125,\"districtname\":\"बांसवाड़ा\",\"District_NameEng\":\"BANSWARA\",\"Loc_District\":8128,\"districtname\":\"बारां \",\"District_NameEng\":\"BARAN\",\"Loc_District\":8115,\"districtname\":\"बाड़मेर \",\"District_NameEng\":\"BARMER\",\"Loc_District\":8105,\"districtname\":\"भरतपुर \",\"District_NameEng\":\"BHARATPUR\",\"Loc_District\":8122,\"districtname\":\"भीलवाडा \",\"District_NameEng\":\"BHILWARA\",\"Loc_District\":8101,\"districtname\":\"बीकानेर \",\"District_NameEng\":\"BIKANER\",\"Loc_District\":8121,\"districtname\":\"बून्दी \",\"District_NameEng\":\"BUNDI\",\"Loc_District\":8126,\"districtname\":\"चित्तौड़गढ़ \",\"District_NameEng\":\"CHITTORGARH\",\"Loc_District\":8102,\"districtname\":\"चूरू \",\"District_NameEng\":\"CHURU\",\"Loc_District\":8109,\"districtname\":\"दौसा \",\"District_NameEng\":\"DAUSA\",\"Loc_District\":8106,\"districtname\":\"धौलपुर \",\"District_NameEng\":\"DHOLPUR\",\"Loc_District\":8124,\"districtname\":\"डूंगरपुर \",\"District_NameEng\":\"DUNGARPUR\",\"Loc_District\":8099,\"districtname\":\"गंगानगर \",\"District_NameEng\":\"GANGANAGAR\",\"Loc_District\":8100,\"districtname\":\"हनुमानगढ \",\"District_NameEng\":\"HANUMANGARH\",\"Loc_District\":8110,\"districtname\":\"जयपुर \",\"District_NameEng\":\"JAIPUR\",\"Loc_District\":8114,\"districtname\":\"जैसलमेर \",\"District_NameEng\":\"JAISALMER\",\"Loc_District\":8116,\"districtname\":\"जालोर \",\"District_NameEng\":\"JALORE\",\"Loc_District\":8129,\"districtname\":\"झालावाड \",\"District_NameEng\":\"JHALAWAR\",\"Loc_District\":8103,\"districtname\":\"झुंझुंनु \",\"District_NameEng\":\"JHUNJHUNU\",\"Loc_District\":8113,\"districtname\":\"जोधपुर \",\"District_NameEng\":\"JODHPUR\",\"Loc_District\":8107,\"districtname\":\"करौली \",\"District_NameEng\":\"KAROULI\",\"Loc_District\":8127,\"districtname\":\"कोटा \",\"District_NameEng\":\"KOTA\",\"Loc_District\":8112,\"districtname\":\"नागौर \",\"District_NameEng\":\"NAGAUR\",\"Loc_District\":8118,\"districtname\":\"पाली \",\"District_NameEng\":\"PALI\",\"Loc_District\":8131,\"districtname\":\"प्रतापगढ \",\"District_NameEng\":\"PRATAPGARH\",\"Loc_District\":8123,\"districtname\":\"राजसमन्द \",\"District_NameEng\":\"RAJSAMAND\",\"Loc_District\":8108,\"districtname\":\"सवाई माधोपुर \",\"District_NameEng\":\"SAWAI MADHOPUR\",\"Loc_District\":8111,\"districtname\":\"सीकर \",\"District_NameEng\":\"SIKAR\",\"Loc_District\":8117,\"districtname\":\"सिरोही \",\"District_NameEng\":\"SIROHI\",\"Loc_District\":8120,\"districtname\":\"टोंक \",\"District_NameEng\":\"TONK\",\"Loc_District\":8130,\"districtname\":\"उदयपुर \",\"District_NameEng\":\"UDAIPUR\"]"


// Convert your response string to data or if you've data then pass it directly
let jsonData = responseStr.data(using: .utf8)

do 
  let json = try JSONSerialization.jsonObject(with: jsonData!, options: [])
  if let array = json as? [[String : AnyObject]] 
    for obj in array 
      let distName = obj["districtname"]
      print("\(String(describing: distName!))")
    
  

catch 
  print("Couldn't parse json \(error)")

【讨论】：

当我这样做时：让 responseStr = string 然后出现此错误 JSON 文本没有以数组或对象开头，并且允许未设置片段的选项

你能告诉我你给变量string赋值的代码

还有print("\(string)") 打印什么？

print("(string)") 这会在控制台上给出响应 >>> ["Loc_District":8119,"districtname":" अजमेर ","District_NameEng":"AJMER", "Loc_District":8104,"districtname":"अलवर ","District_NameEng":"ALWAR"]

@singh Post some code [edit your question]，找不到问题

【参考方案3】：

将 json 转换为字典数组。

let mainarray = jsondata as? [[String:Any]]