IOS SWIFT 網路請求JSON解析 基礎一

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前言：移動互連網時代，網路通訊已經是手機端必不可少的功能。應用中也必不可少地使用了網路通訊，增強用戶端與伺服器互動。使用NSURLConnection實現HTTP的通訊。NSURLConnection 提供了非同步請求和同步請求兩種通訊方式。同步請求資料會造成主線程阻塞，通常在請求大資料或網路不通暢時不建議使用。

不管同步請求還是非同步請求，建立通訊的步驟是一樣的：

1 建立NSURL

2 建立NSURLRequest

3 建立NSURLConnection

當NSURLConnection 建立成功後，就會建立一個HTTP串連。非同步請求和同步請求的區別是：建立了非同步請求，使用者可以做其他的操作，請求會再另一個線程執行，通訊結果及過程會在回呼函數中執行。同步請求則不同，需要請求結束使用者才能做其他的操作。

 

import UIKitclass ViewController: UIViewController,NSURLConnectionDataDelegate {    var jsonData = NSMutableData()    override func viewDidLoad() {        super.viewDidLoad()        // Do any additional setup after loading the view, typically from a nib.                //SynchronousRequest()        //AsynchronousRequest()    }        //同步請求    func SynchronousRequest() -> Void {        //建立需要求的NSURL        var url : NSURL! = NSURL(string: "http://m.weather.com.cn/mweather/101010100.html")        //建立請求對象        var request = NSURLRequest(URL: url)        //定義響應對象        var response : NSURLResponse?        //定義錯誤對象        var error : NSError?        //發出請求        var data = NSURLConnection.sendSynchronousRequest(request, returningResponse: &response, error: &error)                if (error != nil) {            //處理錯誤            println(error?.code)            println(error?.description)        } else {            var josnstring = NSString(data: data!, encoding: NSUTF8StringEncoding)            //轉為字串            println(josnstring)        }            }    //非同步請求    func AsynchronousRequest() -> Void {        //建立需要求的NSURL        var url : NSURL! = NSURL(string: "http://m.weather.com.cn/mweather/101010100.html")        //建立請求對象        var request = NSURLRequest(URL: url)        //建立串連        var connection = NSURLConnection(request: request, delegate: self)        //暫時理解不透徹，待深入瞭解        connection?.scheduleInRunLoop(NSRunLoop.currentRunLoop(), forMode: NSRunLoopCommonModes)        //開始        connection?.start()    }        //將要發送請求    func connection(connection: NSURLConnection, willSendRequest request: NSURLRequest, redirectResponse response: NSURLResponse?) -> NSURLRequest? {        return request    }        //接收響應    func connection(connection: NSURLConnection, didReceiveResponse response: NSURLResponse) {            }        //收到資料    func connection(connection: NSURLConnection, didReceiveData data: NSData) {        self.jsonData.appendData(data)    }        //需要新的內容流    func connection(connection: NSURLConnection, needNewBodyStream request: NSURLRequest) -> NSInputStream? {        return request.HTTPBodyStream    }        //發送資料請求    func connection(connection: NSURLConnection, didSendBodyData bytesWritten: Int, totalBytesWritten: Int, totalBytesExpectedToWrite: Int) {            }        //緩衝響應    func connection(connection: NSURLConnection, willCacheResponse cachedResponse: NSCachedURLResponse) -> NSCachedURLResponse? {        return cachedResponse    }        //請求結束    func connectionDidFinishLoading(connection: NSURLConnection) {        //請求的結果        var jsonstring = NSString(data: self.jsonData, encoding: NSUTF8StringEncoding)  //轉為字串                //println(jsonstring)                //解析json        let dict : AnyObject? = NSJSONSerialization.JSONObjectWithData(self.jsonData, options: NSJSONReadingOptions.AllowFragments, error: nil)                var dic = dict as! NSDictionary                let weatherinfo = dic.objectForKey("weatherinfo") as! NSDictionary        let city = weatherinfo.objectForKey("city") as! String        let date_y = weatherinfo.objectForKey("date_y") as! String        let temp1 = weatherinfo.objectForKey("temp1") as! String            }    override func didReceiveMemoryWarning() {        super.didReceiveMemoryWarning()        // Dispose of any resources that can be recreated.            }}

 

IOS SWIFT 網路請求JSON解析 基礎一