iOS 多线程下的NStimer 的使用

//开启多线程一直扫描 当前wifi是否和扫描到的wifi相同
                    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
                        [NSTimer scheduledTimerWithTimeInterval:1.0f target:self selector:@selector(isGoWebView:) userInfo:nil repeats:YES];
//                        do {
//                            [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
//                        } while (isCurrentWifiNameEqualToScanWifiName == NO);   //当前wifi与扫码扫到的wifi不相同时
                        
                        while (isCurrentWifiNameEqualToScanWifiName == NO) {
//                            [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
                            
//                            [runLoop runUntilDate:[NSDate dateWithTimeIntervalSinceNow:10.0]]; //每隔10秒检查下线程循环条件
                            [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate dateWithTimeIntervalSinceNow:1.0f]];
                        }
                        
                        if (isCurrentWifiNameEqualToScanWifiName == YES) {
                            dispatch_async(dispatch_get_main_queue(), ^{
                                WebViewController *wVC = [[WebViewController alloc] init];
                                [self.navigationController pushViewController:wVC animated:YES];
                                [wVC loadDataWithUrlStr:_regularString];
                            });
                        }
                        
                    });
                    
                    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
                        NSTimer *timer = [NSTimer timerWithTimeInterval:1.0f target:self selector:@selector(isGoWebView:) userInfo:nil repeats:YES];
                        NSRunLoop *runLoop = [NSRunLoop currentRunLoop];
                        [runLoop addTimer:timer forMode:NSDefaultRunLoopMode];
                        while (isCurrentWifiNameEqualToScanWifiName == NO) {
                            [runLoop runUntilDate:[NSDate dateWithTimeIntervalSinceNow:1.0f]];
                        }
                        
                        if (isCurrentWifiNameEqualToScanWifiName == YES) {
                            dispatch_async(dispatch_get_main_queue(), ^{
                                WebViewController *wVC = [[WebViewController alloc] init];
                                [self.navigationController pushViewController:wVC animated:YES];
                                [wVC loadDataWithUrlStr:_regularString];
                            });
                        }
                    });