addSubView-在UIView中添加按钮也会为其SuperView添加相同的按钮

Question

I am following this tutorial to create a rating button - https://developer.apple.com/library/prerelease/ios/referencelibrary/GettingStarted/DevelopiOSAppsSwift/Lesson5.html

I created a UIView inside a UIViewController inside the Storyboard by drag and drop and that UIView is controlled by the below class.

class RatingControl: UIView {

    required init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        let button = UIButton(frame: CGRect(x: 0, y: 0, width: 44, height: 44))
        button.backgroundColor = UIColor.redColor()
        button.addTarget(self, action: "ratingButtonTapped:", forControlEvents: .TouchDown)
        addSubview(button)
    }

    override func intrinsicContentSize() -> CGSize {
        return CGSize(width: 320, height: 44)
    }

    func ratingButtonTapped(button: UIButton) {
        print("Button pressed 👍")
    }
}

The problem is when I add the UIButton, it's showing two buttons, one in it's parent UIViewController at location (x:0, y:0) in addition to the one inside the UIView. I want the button to be showing only inside the UIView inside the UIViewController.

I researched ways to prevent it, one way is to add these buttons manually in the storyboard instead of creating them in the init, but then I am curious how it works fine in the tutorial. I am using iOS 8.3.

Screenshot:

Answer 1

you must have subclassed the UIViewControllers view class also to RatingControl and also the view that you have added because of which it is showing it twice. Kindly check it because it works proper if u only add it to the view you need

If you have added the subclass to the ViewControllers view as well you would get this , which is as per your scenario

Answer 2

try instead of

addSubview(button)

this:

view.addSubview(button)

it will add this button to your viewController