iOS網路編程--NSConnection的同步串連與非同步串連

 1 // 2 //  ZFViewController.m 3 //  0628-表單驗證 4 // 5 //  Created by zfan on 14-6-28. 6 //  Copyright (c) 2014年 zfan. All rights reserved. 7 // 8  9 #import "ZFViewController.h"10 #import "MBProgressHUD+MJ.h"11 12 @interface ZFViewController ()13 14 @property (weak, nonatomic) IBOutlet UITextField *userNameTextField;15 @property (weak, nonatomic) IBOutlet UITextField *passWordTextField;16 17 @end18 19 @implementation ZFViewController20 21 - (void)viewDidLoad22 {23     [super viewDidLoad];24 }25 26 - (IBAction)login:(id)sender27 {28     //驗證帳號和密碼是否合法29     if (self.userNameTextField.text.length == 0)30     {31         [MBProgressHUD showError:@"請輸入帳號"];32         return;33     }34     35     if (self.passWordTextField.text.length == 0)36     {37         [MBProgressHUD showError:@"請輸入密碼"];38         return;39     }40     41     //取出帳號和密碼42     NSString *userName = self.userNameTextField.text;43     NSString *password = self.passWordTextField.text;44     45     //產生URL46     NSString *urlPath = [NSString stringWithFormat:@"http://192.168.1.101:8080/ZFServer/login?username=%@&pwd=%@", userName, password];47     NSURL *url = [NSURL URLWithString:urlPath];48     49     //產生串連50     NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url];51     52     //建立串連並接收返回資料(同步執行)53 //    NSData *loginData = [NSURLConnection sendSynchronousRequest:urlRequest returningResponse:nil error:nil];54     55     56     //建立串連並接收返回資料(非同步執行)57     NSOperationQueue *queue = [[NSOperationQueue alloc] init];58     [NSURLConnection sendAsynchronousRequest:urlRequest queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {59         NSData *loginData = data;60         NSLog(@"%ld", (unsigned long)loginData.length);61     }];62     63     //列印返回的資料長度64     NSLog(@"%@", self.userNameTextField.text);65     NSLog(@"%@", self.passWordTextField.text);66 //    NSLog(@"%ld", (unsigned long)loginData.length);67 }68 69 @end

知識要點:

1>通過NSString類方法拼接字串,產生完整的URL路徑;

2>通過NSURLRequest的類方法,利用URL建立一個NSURLRequest串連執行個體;

3>通過NSConnection的類方法建立串連並接受返回資料,可通過同步方式和非同步方式實現:

 

　　3.1>同步方式

[NSURLConnection sendSynchronousRequest:urlRequest returningResponse:nil error:nil];

　　此方法不會建立線程,傳回值為NSData,由於未建立線程,因此在該方法未完成前,線程不會繼續向下運行,容易造成卡死;

 

　　3.2>非同步方式

NSOperationQueue *queue = [[NSOperationQueue alloc] init];[NSURLConnection sendAsynchronousRequest:urlRequest queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {　　NSData *loginData = data;　　NSLog(@"%ld", (unsigned long)loginData.length);}];

　　此方法會建立一個新的線程用於接受網路端返回資料,傳回值為void,當資料接受完畢後會執行block中的語句;