ios - 使用 addTarget : action: forControlEvents: 将 indexPath.row 移动到标签

Question

我正在尝试将我的 indexPath.row 移动到不同的 View Controller - pageView 标签。这是我尝试过的:

[cell.nav addTarget:self action:@selector(naviguate:) forControlEvents:UIControlEventTouchUpInside];
    cell.nav.tag=indexPath.row;

-(void)naviguate:(id)sender {
    UIButton *theButton=(UIButton *)sender;
    NSLog(names[theButton.tag]);
    pageView *secondViewController = [[pageView alloc] initWithNibName:@"secondViewController" bundle:nil];
    
    secondViewController.name.text = names[theButton.tag];
}

为什么这不会更改 pageView 上的标签文本。我应该怎么做？

---

Logs 字符串工作正常的地方。

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为@danh 编辑

我试过这个:

-(void)naviguate:(id)sender {
    [UIView animateWithDuration:0.5
                          delay:0
                        options: UIViewAnimationOptionCurveEaseOut
                     animations:^{
                         
                         [_tableView setFrame:CGRectMake(0, 569, _tableView.frame.size.width, _tableView.frame.size.height)];
                     }
                     completion:^(BOOL finished){
                         [self performSegueWithIdentifier:@"link" sender:self];
                     }];
    
}

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
    UIButton *theButton=(UIButton *)sender;
    
    if([segue.identifier isEqualToString:@"link"])
    {
        UINavigationController *navController = (UINavigationController *)segue.destinationViewController;
        pageView *controller = (pageView *)navController.topViewController;
        controller.name.text= names[theButton.tag];
    }
}

它被调用的地方

[cell.nav addTarget:self action:@selector(naviguate:) forControlEvents:UIControlEventTouchUpInside];
    cell.nav.tag=indexPath.row;

但我收到错误 [pageView topViewController]: unrecognized selector sent to instance ... Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[pageView topViewController]: unrecognized selector sent to instance

你知道为什么吗？

---

第二次尝试

与:

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
    UIButton *theButton=(UIButton *)sender;
    if([segue.identifier isEqualToString:@"link"])
    {
        pageView *controller = (pageView *)segue.destinationViewController;
        controller.name.text= names[theButton.tag];
    }
}

我收到错误 '-[ImagesTableViewController tag]: unrecognized selector sent to instance

WHich 因为 names[theButton.tag] 崩溃了怎么办？

Answer 1

这一行:

pageView *secondViewController = [[pageView alloc] initWithNibName:@"secondViewController" bundle:nil];

创建一个新的 View Controller ，然后这一行:

secondViewController.name.text = names[theButton.tag];

设置其中一个 View 的属性(这是错误的，因为 View 还没有加载，而且乱用另一个 vc 的 View 是不明智的)。但这并不重要，因为这一行:

}

销毁新分配的 vc，它将永远不会再被听到。

修复的方法是从起始 View Controller 使用 segue，并在 prepareForSegue: 中设置目标属性，或者推送或呈现 secondViewController。要么:

// if we're in a navigation controller
[self.navigationController pushViewController:secondViewController animated:true];

// or, if there's no container
[self presentViewController:secondViewController animated:true completion:nil];

请记住，无论您决定如何呈现 secondViewController，都不要尝试直接设置其中一个 subview 的状态。相反，给它一个像 NSString *theStringMyLabelShouldShow 这样的属性，并从呈现的 vc 中设置它。第二个 VC 可以在 viewWillAppear:

中弄乱它自己的 View

self.name.text = self.theStringMyLabelShouldShow;