限制Facebook登录按钮

Question

我试图限制我的Facebook登录按钮，但宽度与其他按钮的宽度不匹配。

这是我的代码，用于限制Facebook登录按钮

var facebookButton = FBSDKLoginButton()

此代码在viewDidLayoutSubviews函数中

        // Constraints for button
for const in facebookButton.constraints{
        if const.firstAttribute == NSLayoutAttribute.height && const.constant == 28{
            facebookButton.removeConstraint(const)
        }
    }

facebookButton.heightAnchor.constraint(equalToConstant: 40).isActive = true
//facebookButton.widthAnchor.constraint(equalTo: googleSignUpButton.widthAnchor).isActive = true
facebookButton.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor, constant: 63)
facebookButton.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: 64)
facebookButton.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
facebookButton.bottomAnchor.constraint(equalTo: googleSignUpButton.topAnchor, constant: -15).isActive = true

这是输出，我希望facebook按钮的宽度与其他按钮的宽度匹配。

Answer 1

执行以下操作之一：

1：为所有按钮设置固定宽度。

2：将前导锚和尾锚设置为Google按钮的前锚和尾锚。

3：使用UIStackView

Answer 2

将此代码放入viewDidLoad

view.addSubview(facebookButton)
facebookButton.translatesAutoresizingMaskIntoConstraints = false
facebookButton.heightAnchor.constraint(equalToConstant: 40).isActive = true
facebookButton.widthAnchor.constraint(equalTo: googleSignUpButton.widthAnchor).isActive = true
facebookButton.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
facebookButton.bottomAnchor.constraint(equalTo: googleSignUpButton.topAnchor, constant: -15).isActive = true