ios - 使用 Swift 以编程方式向按钮添加约束

Question

我正在努力向我想快速添加到 UIMapView 的位置查找器按钮添加约束，到目前为止，我的约束似乎都没有起作用，按钮卡在左上角，这是我的代码:

override func loadView() 
{
mapView = MKMapView()
view = mapView

let margins = view.layoutMarginsGuide

let locationButton = UIButton()
mapView.addSubview(locationButton)

locationButton.setTitle("find location", for: [])
locationButton.backgroundColor = UIColor.lightGray().withAlphaComponent(0.6)
locationButton.layer.cornerRadius = 3
locationButton.sizeToFit()
locationButton.translatesAutoresizingMaskIntoConstraints = true

locationButton.bottomAnchor.constraint(equalTo: margins.bottomAnchor, constant: 20).isActive = true
locationButton.leadingAnchor.constraint(equalTo: margins.leadingAnchor).isActive = true
locationButton.trailingAnchor.constraint(equalTo: margins.trailingAnchor).isActive = true
}

我们将不胜感激任何帮助。

Answer 1

设置

    locationButton.translatesAutoresizingMaskIntoConstraints = false