Question

我正在使用NSOperation队列来解析一个url并在完成后加载UITableview，这里是我的代码，我在NSOperation队列中使用dispatch_async，我的问题是，我可以使用这种代码，这种方法是错误的吗？

 queue = [[NSOperationQueue alloc]init];
 NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self
                                                                                     selector:@selector(loadDataWithOperation) object:nil];
      [queue addOperation:operation];

 - (void) loadDataWithOperation {

   __block NSData *data = [[NSData alloc] init];
    dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void){

        NSURL *dataURL = [NSURL URLWithString:[NSString stringWithFormat:@"url"]];
        NSError *err=nil;
        data=[NSData dataWithContentsOfURL:dataURL options:NSDataReadingUncached error:&err];

        dispatch_async(dispatch_get_main_queue(), ^(void){

            NSError *err=nil;

            NSDictionary *response_login;


            if(!err)
            {
                [bookingTime removeAllObjects];
                [duration removeAllObjects];
                [guestNumber removeAllObjects];
                [status removeAllObjects];

                response_login = [NSJSONSerialization JSONObjectWithData:data options:0 error:&err];
                 NSArray *TimeSlotList=[[response_login  objectForKey:@"ResultInfo"]objectForKey:@"TimeSlotList"];

                if( [TimeSlotList count]>0 )
                {
                    for(NSDictionary *dict in TimeSlotList)
                    {

                        [bookingTime addObject:[dict objectForKey:@"BookingTime"]];
                        [duration addObject:[dict objectForKey:@"Duration"]];
                        [status addObject:[NSString stringWithFormat:@"%@",[dict objectForKey:@"IsBlocked"]]];
                         [guestNumber addObject:[dict objectForKey:@"AvailCount"]];


                    }


                    [self.view addSubview:bookingDetails];
                    [self.bookingDetails reloadData];
                }
                else
                {

                    res1.text=@"No available timeslot Found";
                    [self.view addSubview:res];

                }
            }


        });
    });

}

Answer 1

以这种方式使用NSOperationQueue似乎毫无意义。

您似乎也有直接访问实例变量而不是访问者的习惯。您应该使用下划线字符启动所有实例变量，以使读取代码的任何人都能看到它。使用实例变量而不是访问器可能会导致很难找到的错误。

使用NSOperation队列调度dispas_async

1 个答案: