得到的数据如何直接赋值给外部变量？

还是不行，卡这里三天了，着急啊啊啊。。。。。。老师，您还有别的办法吗，关于提取post请求返回的数据的

声明变量和set，get方法

实现这两个方法

在网络请求中调用set方法

这些是关于网络请求的所有代码内容，viewcontroller中有个按钮，按钮的响应方法就是这个-(void)send_verification_code函数；最后面的是打印的内容


@interface RegisteredWindowViewController (){
    NSString *register_token;  
}
- (void)viewDidLoad {
    [super viewDidLoad];
    register_token = [[NSString alloc]init];
}

-(void)send_verification_code{
    
    //拿到手机号
    [regist_tf_phonenumber resignFirstResponder];
    NSString *phone_number = [regist_tf_phonenumber.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
    
    if(phone_number.length!=11){
        [self showAlert:@"提示" message:@"请输入正确的手机号"];
    }
    else{
        
    //请求发送验证码

        NSURL *url_yj_sendcode = [NSURL URLWithString:@"http://123.207.85.37:8080/user/register_a.do"];
        NSDictionary *parametersDict = @{@"token":@"sendCode",@"phone":phone_number};
        
        
        //创建request请求
        NSMutableURLRequest *rq_send_code = [NSMutableURLRequest requestWithURL:url_yj_sendcode];
        
        //以“key=value&”的方式创建请求体
        NSMutableString *parameterString = [[NSMutableString alloc]init];
        int pos =0;
        for (NSString *key in parametersDict.allKeys) {
            // 拼接字符串
            [parameterString appendFormat:@"%@=%@", key, parametersDict[key]];
            if(pos<parametersDict.allKeys.count-1){
                [parameterString appendString:@"&"];
            }
            pos++;
        }
        //        NSLog(@"%@",parameterString);
        NSData *parametersData = [parameterString dataUsingEncoding:NSUTF8StringEncoding];
        //设置请求参数
        [rq_send_code setHTTPMethod:@"POST"];
        [rq_send_code setTimeoutInterval:8.0];
        [rq_send_code setHTTPBody:parametersData];
        
        NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
        
        NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration];
        
        
        
        //创建会话任务
        NSURLSessionDataTask *task = [session dataTaskWithRequest:rq_send_code completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
            // 判断是否请求成功
            if (error) {
                NSLog(@"post error :%@",error.localizedDescription);
            }else {
                // 如果请求成功，则解析数据。
                id object = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:&error];
                // 判断是否解析成功
                if (error) {
                    NSLog(@"post error :%@",error.localizedDescription);
                }else {
                    // 解析成功，处理数据，通过GCD获取主队列，在主线程中刷新界面。
                    NSLog(@"post success :%@",object);
                    dispatch_async(dispatch_get_main_queue(), ^{
                        // 刷新界面...
                    });
                    
                    id id_code = [(NSDictionary *)object objectForKey:@"data"];
                    
                    NSLog(@"请求体内部打印：%@",id_code);
                    
                    self->register_token =[(NSDictionary *)id_code objectForKey:@"register_token"];
                    
                    NSLog(@"请求体内部打印：%@",self->register_token);
                    
                }
            }
            
        }];
        
        //执行任务
        [task resume];
        
        
        NSLog(@"请求体外部打印：%@",self->register_token);
    }
}

@end


打印的内容：
2018-08-27 14:47:39.337542+0800 语境[44249:2504477] 请求体外部打印：
2018-08-27 14:47:39.399943+0800 语境[44249:2504477] Can't find keyplane that supports type 4 for keyboard iPhone-PortraitTruffle-NumberPad; using 6919991127445953680_PortraitTruffle_iPhone-Simple-Pad_Default
2018-08-27 14:47:39.539340+0800 语境[44249:2504579] [] nw_proxy_resolver_create_parsed_array PAC evaluation error: NSURLErrorDomain: -1004
2018-08-27 14:47:39.573061+0800 语境[44249:2504582] post success :{
    data =     {
        "register_token" = F1A91D7460E3F7EBED719AEFB2AEC8DC;
    };
    msg = "\U53d1\U9001\U6210\U529f!";
    status = 200;
}
2018-08-27 14:47:39.573354+0800 语境[44249:2504582] 请求体内部打印：{
    "register_token" = F1A91D7460E3F7EBED719AEFB2AEC8DC;
}
2018-08-27 14:47:39.573580+0800 语境[44249:2504582] 请求体内部打印：F1A91D7460E3F7EBED719AEFB2AEC8DC
2018-08-27 14:49:39.460370+0800 语境[44249:2504582] Received XPC error Connection interrupted for message type 3 kCFNetworkAgentXPCMessageTypePACQuery

老师，我刚刚试了一下把数据存储到本地的方法，但是每次读取时都是上次存入的数据，而不是本次请求返回的数据，在这里卡了好久了，到底该怎么做啊，老师

上面这些都是写在一个方法里面，进入方法后声明定义的register_token

-(void)input_verification_code{
    
    __block  NSDictionary *register = [[NSDictionary alloc]init];

......

}

这跟作用域有关系，你的register_token在哪里声明定义的。