Ios 使用NSOperation，我想向当前UIViewController添加子视图，但不确定如何从操作内部访问此子视图

我有一个

NSOperation

，它获取一个消息对象数组并在其中循环。对于每个消息对象，我想向当前的

UIViewController

添加一个

UIView

。唯一的问题是我无法从

NSOperation

访问视图。这有什么办法吗

谢谢

下面的代码（我在NSO操作中的主要方法）：

---

你能发布一些代码吗？对不起，刚刚编辑过

- (void)main {

    //main code here

    NSLog(@"Display messages");

    //First match the user with the messageBank
    PFQuery *messageBankQuery = [PFQuery queryWithClassName:@"messageBank"];
    [messageBankQuery whereKey:@"username" equalTo:[PFUser currentUser].username];
    [messageBankQuery findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {

        if(!error) {

            //first object matches
            PFObject *messageBank = objects[0];
            PFRelation *receivedMessages = [messageBank relationForKey:@"receivedMessages”];
            PFQuery *receivedMessagesQuery = [receivedMessages query];
            [receivedMessagesQuery orderByAscending:@"createdAt"];

            [receivedMessagesQuery findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {

                if((!error) &&([objects count]>0)) {

                    for(PFObject *message in objects) {



                        UIView *content = [[[NSBundle mainBundle] loadNibNamed:@"messageView" owner:self options:nil] objectAtIndex:0];


                        //this doesn't have a view to add to!!!

                    }

                    [self completeOperation];
                }//end if

                else {

                    [self completeOperation];                 }

            }];

        }


    }];    



}