JSON解析Swift錯誤

Question

我是iOS編程新手，我正在嘗試使用Swift新語言。 我有一個問題/我不知道如何解析與iOS的Swift的JSON使用。我已經使用JSON在Android的，所以我知道，JSON和鏈接是正確的，但是當我嘗試下面的代碼（在教程中看到的）的應用程序似乎崩潰，並強調這一行：

var jsonResult = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: &err) as NSDictionary 

的控制檯給我回這個錯誤：

The operation couldn’t be completed. (NSURLErrorDomain error -1005.) fatal error: unexpectedly found nil while unwrapping an Optional value 

這裏是按鈕的操作的全部代碼：

let urlAsString = "http://xxxxxxxxxx.altervista.org/App/_DD_/downloadutenti.php?email="+campoEmail.text+"&password="+campoPassword.text 
    let url = NSURL(string: urlAsString)! 
    let urlSession = NSURLSession.sharedSession() 

    println(url) 
    println(urlSession) 
    let jsonQuery = urlSession.dataTaskWithURL(url, completionHandler: { data, response, error -> Void in 
     if (error != nil) { 
      println(error.localizedDescription) 
     } 
     var err: NSError? 

     if(data != nil){ 
      var jsonResult = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: &err) as NSDictionary 


     if (err != nil) { 
      println("JSON Error \(err!.localizedDescription)") 
     } 

      var jsonEmail = "" 
      if var jsonEmail: String! = jsonResult["email"] as? NSString{ 

      } 
      else{ 
       println("PROBLEM 1") 
      } 

      var jsonPassword = "" 
      if var jsonPassword: String! = jsonResult["pass"] as? NSString{ 

      } 
      else{ 
       println("PROBLEM 2") 
      } 

     dispatch_async(dispatch_get_main_queue(), { 
      self.scritta2.text = "Email: " + jsonEmail + " - Password: " + jsonPassword 
     }) 
    } 
    }) 
    jsonQuery.resume() 

NB 我使用xcode6模擬器，我知道肯定的「變量」campoEmail.text和campoPassword.text採取了一個好方法。

JSON它應該給予回覆：

[{"id":"1","email":"lincoln@gmail.com","password":"pass","permessi":"1","stato":"Italia","citta":"Palermo","via":"Via Lincoln, 29","cap":"90100","telefono":"091xxxxxx"}] 

編輯@ neo的幫助： 我編輯喜歡這個按鈕的所有動作，但代碼進入到數據的空檢查..

let curURL: NSURL = NSURL(string: "http://fantacharleston.altervista.org/App/_DD_/downloadutenti.php?email=lincoln@gmail.com&password=pass")! 
     let curRequest: NSURLRequest = NSURLRequest(URL: curURL, cachePolicy: NSURLRequestCachePolicy.ReloadIgnoringLocalAndRemoteCacheData, timeoutInterval: 60) 
     NSURLConnection.sendAsynchronousRequest(curRequest, queue: NSOperationQueue.mainQueue()) { (response: NSURLResponse!, data: NSData?, error: NSError!) -> Void in 

      if (data != nil) { 
       if let jsonArray: NSArray = NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSArray? { 

        let jsonObject: NSDictionary? = jsonArray.objectAtIndex(0) as? NSDictionary 
        if (jsonObject != nil) { 
         NSLog("object: %@", jsonObject!) 
         let email: NSString? = jsonObject?.objectForKey("email") as? NSString 
         let password: NSString? = jsonObject?.objectForKey("password") as? NSString 

         if (email != nil && password != nil) { 
          dispatch_async(dispatch_get_main_queue(), {() -> Void in 
           self.scritta2.text = "Email: " + email! + " - Password: " + password! 
          }) 
         } 


        } 

       } 
      } 
      else{ 
       println("null") 
      } 
     } 

Answer 1

是的我想我知道你的問題在哪裏......你正在試圖把一個JSONArray放到一個NSDictionary中...那不能去...它就像試圖把它放到Java中的JSONObject中。

只需與NSArray交換NSDictionary，並確保獲得像array [0] [「key」]這樣的屬性，而不是像array [「key」]，因爲您正在處理數組，而不是使用字典。 （其如ArrayList，和HashMap在Java中）

試試這個，請...

if let jsonResult: NSArray = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: &err) as NSArray? { 

let jsonEmail: NSString? = jsonResult.objectAtIndex(0).objectForKey("email") 

} 

編輯與代碼，你需要

這是......我寫了一點就像我會用Android的Java編寫的那樣...我想你會變成eas ily得到它......你評論的問題可能是你的JSON沒有「pass」標籤......它的「密碼」...

let curURL: NSURL = NSURL(string: "http://fantacharleston.altervista.org/App/_DD_/downloadutenti.php?email=lincoln@gmail.com&password=pass")! 
     let curRequest: NSURLRequest = NSURLRequest(URL: curURL, cachePolicy: NSURLRequestCachePolicy.ReloadIgnoringLocalAndRemoteCacheData, timeoutInterval: 60) 
     NSURLConnection.sendAsynchronousRequest(curRequest, queue: NSOperationQueue.mainQueue()) { (response: NSURLResponse!, data: NSData?, error: NSError!) -> Void in 

      if (data != nil) { 
       if let jsonArray: NSArray = NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSArray? { 

        let jsonObject: NSDictionary? = jsonArray.objectAtIndex(0) as? NSDictionary 
        if (jsonObject != nil) { 
         NSLog("object: %@", jsonObject!) 
         let email: NSString? = jsonObject?.objectForKey("email") as? NSString 
         let password: NSString? = jsonObject?.objectForKey("password") as? NSString 

         if (email != nil && password != nil) { 
          dispatch_async(dispatch_get_main_queue(), {() -> Void in 
           self.scritta2.text = "Email: " + email + " - Password: " + password 
          }) 
         } 


        } 

       } 
      } 
     }