How can I find the UIView for a specific UITabBarI

问题:

I am using an external library called SwiftyWalkthrough, which allows me to expose only certain views on the screen to guide a new user through my app's UI. The first item I want exposed to the user is a UITabBarItem. I need to find the UIView associated with that specific UITabBarItem. I know the index for the item, and I have given it a tag. But I haven't found a way for them to help me find the view. Of course, I only want to use public interfaces to accomplish this.

回答1:

I solved my problem by accessing the subviews of the tabBar. The views with userInteractionEnabled are UITabBarItems. Sorting them by their minX values guarantees that they are in the same order as the tabBar.items array.

extension UITabBarController {
    func orderedTabBarItemViews() -> [UIView] {
        let interactionViews = tabBar.subviews.filter({$0.isUserInteractionEnabled})
    return interactionViews.sorted(by: {$0.frame.minX < $1.frame.minX})
    }
}

回答2:

Swift 3 version of for Carl Smith's answer

func orderedTabBarItemViews() -> [UIView] {
    let interactionViews = tabBar.subviews.filter({$0.isUserInteractionEnabled})
    return interactionViews.sorted(by: {$0.frame.minX < $1.frame.minX})
}

回答3:

Tested in iOS10 with Objective-C:

[alert setModalPresentationStyle:UIModalPresentationPopover];

    UIView *view = [self.tabBar.selectedItem valueForKey:@"view"];

    alert.popoverPresentationController.delegate = self;
    alert.popoverPresentationController.sourceView = self.tabBar;
    alert.popoverPresentationController.sourceRect = view.frame;
    alert.popoverPresentationController.permittedArrowDirections = UIPopoverArrowDirectionDown;

    [self presentViewController:alert animated:YES completion:nil];