网络篇-----解析json

　　//1.创建url
    NSURL *url=[NSURL URLWithString:@"http://127.0.0.1:8080/MJServer/video"];
    //2.创建请求
    NSURLRequest *request=[NSURLRequest requestWithURL:url];
    //3.发送请求
    [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSD　　　　ata *data, NSError *connectionError) {
        if(connectionError || data==nil){
　　//MBProgressHUD 为第三方框架

　　[MBProgressHUD showError:@"网络超时，请稍后"]; return ; } 

　　//4.解析json数据 
　　NSDictionary *dict= [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];

@interface ViewController ()
@property (weak, nonatomic) IBOutlet UITextField *user;
@property (weak, nonatomic) IBOutlet UITextField *pwd;
- (IBAction)loginBtn:(id)sender;
@end

@implementation ViewController

//退出键盘
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    [self.view endEditing:YES];
}

- (void)viewDidLoad {
    [super viewDidLoad];
}


- (IBAction)loginBtn:(id)sender {
    NSString *usertext=self.user.text;
    if(usertext.length==0){
        [MBProgressHUD showError:@"输入账号"];
        return;
　　 }
    NSString *pwdtext=self.pwd.text;

    if(pwdtext.length==0){
    [MBProgressHUD showError:@"请输入密码"];
        return;
    }
   
//    NSLog(@"%@",pwdtext);
//
//
//发送用户名和密码给服务器
    NSString *sting=[NSString stringWithFormat:@"http://127.0.0.1:8080/MJServer/login?username=%@&pwd=%@",usertext,pwdtext];
    
    NSURL *url=[NSURL URLWithString:sting];
    
    NSURLRequest *request=[NSURLRequest requestWithURL:url];
//发送一个同步请求
//    NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
//    NSLog(@"%@",data);
    //返回到主线程
    NSOperationQueue *queue=[NSOperationQueue mainQueue];
    //发送一个同步请求
    [NSURLConnection sendAsynchronousRequest:request queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError)       
    {
        NSLog(@"%@", [NSThread currentThread]);
             if(connectionError ||data ==nil){
                 [MBProgressHUD showError:@"请求失败"];
                 return; }
            
        
//    解析返回的json数据
    //SONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil  json数据转换为oc对象
    NSDictionary *tionary=[NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];
    NSString *error=tionary[@"error"];
    if(error){
        [MBProgressHUD showError:error];
    }else{
        NSString *secces=tionary[@"secces"];
        [MBProgressHUD showSuccess:secces];
    }
         }];
}