7.31 json2

新建一个类 ChannelModel

import Foundation

class ChannelModel {
    var channel_id: String!           //定义成员变量
    var channel_name: String!
    var coverUrl: NSURL!
    
    init(dict: NSDictionary) {        //写一个构造函数，把dict定义为字典类型
        if let chId = dict["channel_id"] {
            channel_id = chId as! String
        }
        
        if let chName = dict["channel_name"] {
            channel_name = chName as! String
        }
        
        if let cUrl = dict["coverUrl"] {
            coverUrl = NSURL(string: cUrl as! String)
        }
    }
}

回到view control界面：

import UIKit

class ViewController: UIViewController {

   override func viewDidLoad() {
       super.viewDidLoad()
       
       let path = "https://gitshell.com/wcrane/FM-Res/raw/blob/master/channels.json"
       let url = NSURL(string: path)
       
       let task = NSURLSession.sharedSession().dataTaskWithURL(url!) { (data, response, error) in
           guard error == nil else {
               print("连接错误: \(error?.localizedDescription)")
               return
           }
           
           if let httpResponse = response as? NSHTTPURLResponse {
               if httpResponse.statusCode == 200 {
                   if let d = data {
                       let array = try! NSJSONSerialization.JSONObjectWithData(d, options: .AllowFragments) as? NSArray //NSDictionary
                       
                       for dict in array! {
//                            //1. 不会提示
//                            //2. 类型不明确
//                            
//                            //用数据模型对象
//                            //1. 提示
//                            //2. 类型确定
//                            //3. 可以对数据进行初步处理
                           let ch = ChannelModel(dict: dict as! NSDictionary)  
                                   //调用一开始写的ChannelModel函数
                           print(ch.channel_name)      //打印
                       }
                   }
               }
           }
       }
       task.resume()
       
       let jsonStr = "{\"name\":\"Zhangsan\"}"
       //将字符串转换为NSData
       let jsonData = jsonStr.dataUsingEncoding(NSUTF8StringEncoding)
       let jsonObj = try! NSJSONSerialization.JSONObjectWithData(jsonData!, options: .AllowFragments)
       print(jsonObj["name"])
       
       //Swift -> JSON
       let dict1 = ["中文", "日文", "英文"]
       //由第二个参数决定是否需要空格、换行之类格式化字符
       let data1 = try! NSJSONSerialization.dataWithJSONObject(dict1, options: [])
       let jsonStr1 = NSString(data: data1, encoding: NSUTF8StringEncoding)
       print(jsonStr1!)
   }

   override func didReceiveMemoryWarning() {
       super.didReceiveMemoryWarning()
       // Dispose of any resources that can be recreated.
   }
}