来自另一个类的pushViewController [英] pushViewController from another class

问题描述

我想从我的 FirstViewController 中推送视图控制器以加载 BookDetailsViewController .这是我目前的设置.

I want to push a view controller from my FirstViewController to load BookDetailsViewController. here's the setup I currently have.

// FirstViewController:(this is inside a uinavigationcontroller)

    -(IBAction)viewBookDetails:(id)sender
    {
      NSLog(@"woo");
      BookDetailsViewController *bdvc = [[BookDetailsViewController alloc] init];
      [self.navigationController pushViewController:bdvc animated:YES];
    }

    ==============================================================        

// BookScrollViewController: (where the button is located)

    [book1UIButton addTarget:self action:@selector(viewBookDetails:)   
    forControlEvents:UIControlEventTouchUpInside];

     -(void)viewBookDetails:(id) sender
    {
      FirstViewController *fvc = [[FirstViewController alloc] init];
      [fvc viewBookDetails:sender];
    }

    ============================================================== 

    //how BookScrollViewController is created
    BookScrollViewController *controller = [bookViewControllersArray  
    objectAtIndex:page];

    if ((NSNull *)controller == [NSNull null]) {
      NSString *bookTitle = @"ngee";
      controller = [[BookScrollViewController alloc]initWithBook:bookTitle  
      imageNamesArray:imgDataArray pageNumber:page totalResult:[newReleasesArray 
      count]];

      [bookViewControllersArray replaceObjectAtIndex:page withObject:controller];
      [controller release];
    }

    // add the controller's view to the scroll view
    if (nil == controller.view.superview) {
      CGRect frame = bookScroll.frame;
      frame.origin.x = frame.size.width * page;
      frame.origin.y = 0;
      controller.view.frame = frame;
      [bookScroll addSubview:controller.view];
    }

当我点击 BookScrollViewController 中的按钮时，它会调用 FirstViewController 中的 IBAction ，因为它会打印我的nslog，但不会加载推送 BookDetailsViewController 到导航堆栈.

when I tap the button in BookScrollViewController it calls the IBAction I have in FirstViewController coz it prints my nslog but it's not loading pushing the BookDetailsViewController to the navigation stack.

我尝试从 FirstViewController 分配一个按钮来调用 IBAction ，它加载得很好.因此，如何使用 BookScrollViewController 中的按钮从 FirstViewController 中成功调用 IBAction ?

I tried assigning a button from FirstViewController to call the IBAction and it loads just fine. So, how can I successfully call the IBAction from FirstViewController using the button from BookScrollViewController?

谢谢！

推荐答案

执行此操作时:

FirstViewController *fvc = [[FirstViewController alloc] init];

您显然创建了一个FirstViewController的新实例.这个新实例不是UINavigationController中的 ，因此您不能将新的viewController推入其NavigationController属性中.

you obviously create a new instance of FirstViewController. That new instance is not in a UINavigationController, so you can't push a new viewController onto its navigationController property.

您可能想做的是引用FirstViewController的现有实例并对其调用方法，而不是为其创建新实例.

What you probably want to do is reference the existing instance of FirstViewController and call the method on it instead of creating a new instance of it.

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