JSON数据解析1

通过火狐浏览器查看服务器上的JSON格式的数据,

通过请求拿到JSON数据(即data)进行解析,

使用了第三方框架,做了简单封装

注意点:38行路径不要拼接错误,

          系统默认发送GET请求

　　　 程序访问的是本地搭建的服务器

　　　Xcode默认不是HTTP协议,需要在info.plist中添加这段代码

<key>NSAppTransportSecurity</key>
<dict>
<key>NSAllowsArbitraryLoads</key>
<true/>
</dict>

         53行发送请求,等待响应为耗时操作需要在后台线程执行,拿到数据解析,打印要回到主线程.

 

//
//  ViewController.m
//  LDlate发送请求
//
//  Created by apple on 15/11/5.
//  Copyright © 2015年 itcast. All rights reserved.
//

#import "ViewController.h"
#import "MBProgressHUD+LD.h"
@interface ViewController ()
@property (weak, nonatomic) IBOutlet UITextField *userName;
@property (weak, nonatomic) IBOutlet UITextField *pwd;

@end

@implementation ViewController
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    //点击登录退出键盘
    [self.view endEditing:YES];
}
- (IBAction)logIn:(id)sender {
    //1.用户名
    NSString * userNameText = self.userName.text;
    
    if (userNameText.length == 0) {
        [MBProgressHUD showError:@"请输入用户名"];
        return;
    }
    //2.密码
    NSString * pwdText = self.pwd.text;
    if (pwdText.length == 0) {
        [MBProgressHUD showError:@"请输入密码"];
        return;
    }
    //3发送用户名和密码给服务器(HTTP协议,非HTTPS)
    //创建Url:请求路径
    NSString * urlStr = [NSString stringWithFormat:@"http://localhost/login/login.php?username=%@&password=%@",self.userName.text,self.pwd.text];
    NSLog(@"urlStr = %@",urlStr);
    //url中不能包含中文,如包含中文需要进行转码,URL 不能包含 ASCII 字符集中
    urlStr = [urlStr stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];
    NSLog(@"urlStr = %@",urlStr);
    
    NSURL * url = [NSURL URLWithString:urlStr];
    
    NSLog(@"url = %@",url);
    
    //创建请求
    NSURLRequest * request = [NSURLRequest requestWithURL:url];
    
    //异步请求(子线程发送请求),主线程处理任务(更新UI)
    NSOperationQueue *queue = [NSOperationQueue mainQueue];
    [NSURLConnection sendAsynchronousRequest:request queue:queue completionHandler:
     ^(NSURLResponse *response, NSData *data, NSError *connectionError) {
         // 这个block会在请求完毕的时候自动调用
         if (connectionError || data == nil) {
             [MBProgressHUD showError:@"请求失败"];
             return;
         }
         
         // 解析服务器返回的JSON数据
         NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];
         NSLog(@"%@",dict);
         NSString *error = dict[@"error"];
         if (error) {
             // {"error":"用户名不存在"}
             // {"error":"密码不正确"}
             [MBProgressHUD showError:error];
         } else {
             // {"success":"登录成功"}
             NSString *success = dict[@"success"];
             [MBProgressHUD showSuccess:success];
         }
     }];
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}
@end