Question

大家好，我想将Button放在屏幕的下部，但是我没有正确的代码。该按钮太小，太大，在右上角或左上角，...但是它应该位于下部屏幕的中央。

我尝试了以下代码：

nextButton.translatesAutoresizingMaskIntoConstraints = false
        
        nextButton.centerXAnchor.constraint(equalTo: view.centerXAnchor)
        nextButton.centerYAnchor.constraint(equalTo: view.centerYAnchor)
        nextButton.widthAnchor.constraint(equalTo: view.widthAnchor, constant: 97)
        nextButton.heightAnchor.constraint(equalTo: view.heightAnchor, constant: 50)

或

backButton.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20).isActive = true
       backButton.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -20).isActive = true
       backButton.heightAnchor.constraint(equalToConstant: 50).isActive = true
       backButton.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true

有人可以告诉我如何使其正常工作吗？我认为使用topAnchor真的很容易：（

Answer 1

这会将其放置在屏幕的底部中心

nextButton.translatesAutoresizingMaskIntoConstraints = false
    
NSLayoutConstraint.activate([
    nextButton.centerXAnchor.constraint(equalTo: view.centerXAnchor),
    nextButton.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant:-20),
    nextButton.widthAnchor.constraint(equalToConstant: 50),
    nextButton.heightAnchor.constraint(equalToConstant: 50) 
])

Answer 2

问题是您使用的是centerYAnchor而不是bottomAnchor

替换

nextButton.centerYAnchor.constraint(equalTo: view.centerYAnchor)

使用

let spacingConstant = 10.0
nextButton.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -spacingConstant)

以编程方式自动布局按钮？

2 个答案: