发送json到服务器

1，如果发送JSON数据，比如商城下单的时候发送下单信息给服务器，则必须在请求头中说明数据类型
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    NSURL *url = [NSURL URLWithString:@"http://192.168.1.103:8080/MJServer/order"];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    request.HTTPMethod = @"POST";
    NSDictionary *orderInfo = @{
                                @"shop_id":@"12341",
                                @"shop_name":@"zhang",
                                @"user_id":@"danfeng"
                                };
    
    NSData *data01 = [NSJSONSerialization dataWithJSONObject:orderInfo options:NSJSONWritingPrettyPrinted error:nil];
    request.HTTPBody = data01;
    
    [request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
    [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
        NSLog(@"%@",data);
        if(data == nil || connectionError) return ;
        
        NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];
        NSString *error = dict[@"error"];
        NSString *success = dict[@"success"];
        
        if(error){
            NSLog(@"%@",error);
        }else{
            NSLog(@"%@",success );
        }
    }];
}

发送多值参数到服务器

2，多值参数，也就是一个参数中有多个值，直接拼接成字符串放进去即可：
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    NSURL *url = [NSURL URLWithString:@"http://192.168.1.103:8080/MJServer/weather"];
    NSMutableURLRequest *request =  [NSMutableURLRequest requestWithURL:url];
    request.HTTPMethod = @"POST";
    
    NSMutableString *body = [NSMutableString string];
    [body appendString:@"place=beijing"];
    [body appendString:@"&place=shanghai"];
    request.HTTPBody = [body dataUsingEncoding:NSUTF8StringEncoding];
    
    [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
        if(connectionError || data == nil){
            NSLog(@"request failed");
        }
        NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];
        NSString *error = dict[@"error"];
        NSString *weather = dict[@"weathers"];
        if(error){
            NSLog(@"%@",error);
        }else if(weather){
            NSLog(@"%@",weather);
        }
    }];
}