Swift 3 problems解析json响应

Question

我是Swift上的新成员，但我正在回顾一些例子，例如如何使登录应用程序发送用户名和密码字段到PHP文件并获取json响应。

当我打印我的responseString我得到：

[{ “用户id”：1， “用户名”： “罗德里戈”， “密码”： “minhoca”， “组名”： “情侣”}]

但是当我尝试解析JSON我从来没有可以设置用户名变量，因为从来没有进入的那部分代码，我只是得到“这里”

感谢您的帮助

func sendLoginInfo(username: String, password: String) -> String{ 
     if let url = URL(string: "myphpurl"){ 
      let request = NSMutableURLRequest(url:url) 
      request.httpMethod = "POST";// Compose a query string 
      let postString = "?username=\(myUsername)&password=\(myPassword)" 
      request.httpBody = postString.data(using: String.Encoding.utf8) 
      let task = URLSession.shared.dataTask(with:request as URLRequest){ 
       data, response, error in 

       if error != nil{ 
        print("1\(error)") 
       } 
       else{ 
        let responseString = NSString(data: data!, encoding: String.Encoding.utf8.rawValue) 
        print("response string = \(responseString!)") 
       } 

       do { 

        if let convertedJsonIntoDict = try JSONSerialization.jsonObject(with: data!, options: []) as? NSDictionary { 

         // Print out dictionary 
         print(convertedJsonIntoDict) 

         // Get value by key 
         let firstNameValue = convertedJsonIntoDict["username"] as? String 
         print("here = \(firstNameValue!)") 

        } 
        else{ 
         print("here") 
        } 
       } catch let error as NSError { 
        print(error.localizedDescription) 
       } 
      } 
      task.resume() 
     } 
     return "" 
    } 

Answer 1

变化将NSDictionary转换为NSArray在你的代码，因为你得到一个数组，并试图转换到dictonary：

if let convertedJson = try JSONSerialization.jsonObject(with: data!, options: []) as? NSArray 

获得索引0处的对象，这将给你dictonary &那么你可以得到的用户名

所以最终代码会：

func sendLoginInfo(username: String, password: String) -> String{ 
    if let url = URL(string: "myphpurl"){ 
     let request = NSMutableURLRequest(url:url) 
     request.httpMethod = "POST";// Compose a query string 
     let postString = "?username=\(myUsername)&password=\(myPassword)" 
     request.httpBody = postString.data(using: String.Encoding.utf8) 
     let task = URLSession.shared.dataTask(with:request as URLRequest){ 
      data, response, error in 

      if error != nil{ 
       print("1\(error)") 
      } 
      else{ 
       let responseString = NSString(data: data!, encoding: String.Encoding.utf8.rawValue) 
       print("response string = \(responseString!)") 
      } 

      do { 

       if let convertedJsonIntoDict = try JSONSerialization.jsonObject(with: data!, options: []) as? NSArray { 

        // Print out dictionary 
        print(convertedJsonIntoDict) 

        // Get value by key 
        let firstNameValue = (convertedJsonIntoDict[0] as! NSDictionary)["username"] as? String 
        print("here = \(firstNameValue!)") 

       } 
       else{ 
        print("here") 
       } 
      } catch let error as NSError { 
       print(error.localizedDescription) 
      } 
     } 
     task.resume() 
    } 
    return "" 
}