從UITabBar初始化UIViewController的屬性

Question

從TabBar單擊時，我需要設置ViewController的屬性。

我嘗試在didSelectViewController執行此操作-但在ViewWillAppear完成后ViewWillAppear它，並且為時已晚

我嘗試這樣做：

- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController

但是viewController是原始的tabBarIndex而不是目標的tabBarIndex

我能做什么？

Answer 1

在深入研究代碼之后，我找到了一種方法：

- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController
{
    UINavigationController *nav = (UINavigationController *)viewController;
    if ([[nav.viewControllers objectAtIndex:0] isKindOfClass:[DestinationViewController class]])
    {
        DestinationViewController *vc = (DestinationViewController *)[nav.viewControllers objectAtIndex:0];
        vc.foo = 1;
    }

    return YES;
}

Answer 2

如果使用情節提要，則可以設置segue ID，然后：

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([segue.identifier isEqualToString:YOUR_SEGUE_ID]) {
        YourViewController *controller = segue.destinationViewController;
        controller.someProperty = someProperty;
    }
}