Mis-aligned when use frame = bound option in swift - xcode11

Question

I am beginner to iPhone development. I am modifying some code in existing project.

I have a signing button on registration when which is aligned well. constraint set proper. but now I added same code (Apple Sign in button code) to my login Page. but it is not well centered and align. here below is code which I am using for add apple signin button

 if #available(iOS 13.0, *) {
        let authorizationButton = ASAuthorizationAppleIDButton()
        
  
        authorizationButton.addTarget(self, action: #selector(handleLogInWithAppleIDButtonPress), for: .touchUpInside)
        
        authorizationButton.frame = self.appleSignInButton.bounds

        
        self.appleSignInButton.addSubview(authorizationButton)


        
    } else {
        self.appleSignInView.isHidden = true
    }

And Result is as below Image.

But when same code used on registration page

Constraint property also same for both pages.

Answer 1

Don't bother with frames and bounds when aligning views. Let Auto Layout handle that by giving proper constraints:

let authorizationButton = ASAuthorizationAppleIDButton()

authorizationButton.addTarget(self, action: #selector(handleLogInWithAppleIDButtonPress), for: .touchUpInside)

self.appleSignInButton.addSubview(authorizationButton)

// Don't use the frame, place the view using constraints
authorizationButton.translatesAutoresizingMaskIntoConstraints = false

// Set the constraints after adding the view to the view hierarchy
NSLayoutConstraint.activate([
    authorizationButton.leadingAnchor.constraint(equalTo: appleSignInButton.leadingAnchor),
    authorizationButton.trailingAnchor.constraint(equalTo: appleSignInButton.trailingAnchor),
    authorizationButton.topAnchor.constraint(equalTo: appleSignInButton.topAnchor),
    authorizationButton.bottomAnchor.constraint(equalTo: appleSignInButton.bottomAnchor)
])