iOS: On 'Automatic TabBar switched‘方法

Question

我尝试以编程方式切换选项卡，并确保在切换时，相应的导航控制器弹出到根视图控制器。有没有在手动或编程切换选项卡栏时调用的方法？

注意:只有在手动切换选项卡栏时才会调用-(void)tabBarController:didSelectViewController:

Answer 1

您也可以尝试以编程方式调用didSelectViewController。在这里查看babbidi的答案：

How to trigger method "tabBarController:didSelectViewController:" programmatically?

Answer 2

另一种方式是在selectedViewController上使用观察者。

// Add Observer
// Note: tabBarController.selectedIndex is not observed as it does not call observeValueForKeyPath on manual switch
[self.tabBarController addObserver:self forKeyPath:@"selectedViewController" options:NSKeyValueObservingOptionNew context:@"changedTabbarIndex"];

// Method for Handling Observations
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
    NSString *action = (__bridge NSString*)context;
    if([action isEqualToString:@"changedTabbarIndex"])
    {
        // Stuff to do on selected Tab changed
    }
}

// Change selectedViewController
[self.tabBarController setSelectedViewController:[[self.tabBarController viewControllers] objectAtIndex:kSomeTab]];

更多信息：I didn't get any notifications when I touched on tabbar items