如何通过代码用FreeForm创建UIViewController？不使用故事板

Question

使用Freeform选项创建带有代码的UIViewController时遇到问题。 注意：我不为此UIViewController使用故事板。

Answer 1

通常，在viewController中创建UIView

let view2 = UIView()
view2.backgroundColor = .red
self.view.addSubview(view2)

view2.topAnchor.constraint(view.topAnchor, constant: 100).isActive = true
view2.leftAnchor.constraint(view.leftAnchor, constant: 100).isActive = true
view2.bottomAnchor.constraint(view.bottomAnchor, constant: 100).isActive = true
view2.rightAnchor.constraint(view.rightAnchor, constant: 100).isActive = true

如果您要创建viewController并推送到它，则需要创建一个带有UIViewController子类的新文件，然后使用此代码进行导航

self.navigationViewController?.pushViewController(rootViewController: NewFileViewController())