Question

我有按钮视图，当用户按下按钮时，会显示容器视图。我用：

ContainerView.setNeedsDisplay()

更新容器视图。我这样做是因为我有一个标签等UI，我希望文本基于点击的按钮。

问题在于，在更新视图并更新文本时，标签文本不会更改。

Answer 1

感谢Rroobb的评论，这很有效！ - stackoverflow.com/a/37748737/3108877

Answer 2

我写了一个帮助你的帮手，来源可以帮到你：

+ (void)navigateFromController:(UIViewController *)fromController toController:(UIViewController *)toController {
    if (fromController) {
        // Remove any existing child controllers.
        for (UIViewController *child in [toController childViewControllers]) {
            [child willMoveToParentViewController:nil];
            [child.view removeFromSuperview];
            [child removeFromParentViewController];
        }

        // Embed the new controller.
        [fromController addChildViewController:toController];

        toController.view.frame = fromController.view.bounds;
        toController.view.translatesAutoresizingMaskIntoConstraints = false;
        [fromController.view addSubview:toController.view];

        [toController.view.leftAnchor constraintEqualToAnchor:fromController.view.leftAnchor].active = YES;
        [toController.view.rightAnchor constraintEqualToAnchor:fromController.view.rightAnchor].active = YES;
        [toController.view.topAnchor constraintEqualToAnchor:fromController.view.topAnchor].active = YES;
        [toController.view.bottomAnchor constraintEqualToAnchor:fromController.view.bottomAnchor].active = YES;

        [fromController didMoveToParentViewController:fromController];
    }
}

容器视图中的UI未更新

2 个答案: