网络编程之天气预报

摘要: 网络编程之天气预报

创建网络版天气预报 在
http://api.k780.com:88 注册访问相应的接口。具体不做详述。

现在做一个前期的工作。创建一个项目，命名weatherApp，并修改info.list文件，使其支持网络下载

<key>NSAppTransportSecurity</key>

<dict>

<key>NSAllowsArbitraryLoads</key><true/>

</dict>

在IOS最新的版本中加入了这个，应该是基于IOS的安全考虑（推测）

首位我们创建一个weather的构造类

struct Weather {

var city:String?
var weather:String?
var temp:String?
var iconURl:String?

}
系统初始化的时候进行创建weather，并赋值给weather对象。

override func viewDidLoad() {
super.viewDidLoad()
getWeatherData()

}
func getWeatherData(){
let url = NSURL(string: "http://api.k780.com:88/?app=weather.today&weaid=1&&appkey=17466&sign=c2a6fd1e3ef8f80d80d8774cbb6921e1&format=json")
let config = NSURLSessionConfiguration.defaultSessionConfiguration()
config.timeoutIntervalForRequest = 1000
let session = NSURLSession(configuration: config)
session.dataTaskWithURL(url!) { (data:NSData?, res:NSURLResponse?, err:NSError?) -> Void in

do{
let jsondata = try NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers) as! NSDictionary
let weatherDataResult = (jsondata.valueForKey("result") as? NSDictionary).map({
Weather(city: $0["citynm"] as? String, weather: $0["weather"] as? String, temp: $0["temperature_curr"] as? String,iconURl:$0["weather_icon"] as? String)
})
self.weatherData = weatherDataResult

}catch{
print("error")
}
}!.resume()
}
利用IOS特有的侦听器 didset 对界面进行渲染

var weatherData:Weather?{
didSet{
configView()
}
}

func configView(){
cityLab.text = self.weatherData?.city
cityWeather.text = self.weatherData?.weather
cityTemp.text = self.weatherData?.temp
getImg()

}
//根据weatherData的URL，获取天气图标

func getImg() {

// let main:dispatch_queue_t = dispatch_get_main_queue()
dispatch_async(dispatch_get_main_queue()) { () -> Void in

var session2:NSURLSession!
var dataTask2:NSURLSessionDownloadTask!
let iconUrl = NSURL(string: (self.weatherData?.iconURl)!)

//session2 = NSURLSession(configuration: NSURLSessionConfiguration.defaultSessionConfiguration(), delegate: self, delegateQueue: nil)
session2 = NSURLSession(configuration: NSURLSessionConfiguration.defaultSessionConfiguration())
//create task
dataTask2 = session2.downloadTaskWithURL(iconUrl!, completionHandler: { (iconUrl:NSURL?, res:NSURLResponse?, err:NSError?) -> Void in

let data = NSData(contentsOfURL: iconUrl!)
let imgage = UIImage(data: data!)
self.weatherIcon.image = imgage

})
dataTask2.resume()

}

}
至此，系统就能自动加载天气信息

全部代码：

//
// ViewController.swift
// weatherApp
//
// Created by WHJ on 16/1/19.
// Copyright © 2016年 WHJ. All rights reserved.
//

import UIKit

struct Weather {

var city:String?
var weather:String?
var temp:String?
var iconURl:String?

}
//NSURLSessionDownloadDelegate
class ViewController: UIViewController {

@IBOutlet weak var cityLab: UILabel!

@IBOutlet weak var cityWeather: UILabel!

@IBOutlet weak var cityTemp: UILabel!

@IBOutlet weak var weatherIcon: UIImageView!

var weatherData:Weather?{
didSet{
configView()
}
}

func configView(){
cityLab.text = self.weatherData?.city
cityWeather.text = self.weatherData?.weather
cityTemp.text = self.weatherData?.temp
getImg()

}

override func viewDidLoad() {
super.viewDidLoad()
getWeatherData()

}
func getWeatherData(){
let url = NSURL(string: "http://api.k780.com:88/?app=weather.today&weaid=1&&appkey=17466&sign=c2a6fd1e3ef8f80d80d8774cbb6921e1&format=json")
let config = NSURLSessionConfiguration.defaultSessionConfiguration()
config.timeoutIntervalForRequest = 1000
let session = NSURLSession(configuration: config)
session.dataTaskWithURL(url!) { (data:NSData?, res:NSURLResponse?, err:NSError?) -> Void in

do{
let jsondata = try NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers) as! NSDictionary
let weatherDataResult = (jsondata.valueForKey("result") as? NSDictionary).map({
Weather(city: $0["citynm"] as? String, weather: $0["weather"] as? String, temp: $0["temperature_curr"] as? String,iconURl:$0["weather_icon"] as? String)
})
self.weatherData = weatherDataResult

}catch{
print("error")
}
}!.resume()
}

func getImg() {

// let main:dispatch_queue_t = dispatch_get_main_queue()
dispatch_async(dispatch_get_main_queue()) { () -> Void in

var session2:NSURLSession!
var dataTask2:NSURLSessionDownloadTask!
let iconUrl = NSURL(string: (self.weatherData?.iconURl)!)

//session2 = NSURLSession(configuration: NSURLSessionConfiguration.defaultSessionConfiguration(), delegate: self, delegateQueue: nil)
session2 = NSURLSession(configuration: NSURLSessionConfiguration.defaultSessionConfiguration())
//create task
dataTask2 = session2.downloadTaskWithURL(iconUrl!, completionHandler: { (iconUrl:NSURL?, res:NSURLResponse?, err:NSError?) -> Void in

let data = NSData(contentsOfURL: iconUrl!)
let imgage = UIImage(data: data!)
self.weatherIcon.image = imgage

})
dataTask2.resume()

}

}
/* Sent when a download task that has completed a download. The delegate should
* copy or move the file at the given location to a new location as it will be
* removed when the delegate message returns. URLSession:task:didCompleteWithError: will
* still be called.
*/
// func URLSession(session: NSURLSession, downloadTask: NSURLSessionDownloadTask, didFinishDownloadingToURL location: NSURL){
//
// let data = NSData(contentsOfURL: location)
// let imgage = UIImage(data: data!)
// weatherIcon.image = imgage
// }

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

}