如何在iOS中创建一个可以到达屏幕边界的popover？

Question

我想做的是让POPOVER的左上角与父视图的左上角相等，我试过这样的操作：

override func viewDidLoad() {
    super.viewDidLoad()
    let button = UIButton(frame: CGRect(x: 250, y: 250, width: 100, height: 100))
    button.backgroundColor = UIColor.red
    button.addTarget(self, action: #selector(popover), for: .touchUpInside)
    view.addSubview(button)
}

@objc func popover() {
    let contentVC = UIViewController()
    contentVC.view.frame = CGRect(x: 0, y: 0, width: 300, height: 300)
    contentVC.view.backgroundColor = UIColor.blue
    contentVC.modalPresentationStyle = .popover
    contentVC.preferredContentSize = CGSize(width: 300, height: 300)
    let popVC = contentVC.popoverPresentationController
    popVC?.sourceView = view
    popVC?.sourceRect = CGRect(x: 0, y: 0, width: 300, height: 300)
    popVC?.permittedArrowDirections = UIPopoverArrowDirection(rawValue: 0)
    popVC?.popoverLayoutMargins = .zero
    self.present(contentVC, animated: true, completion: nil)
}

然而，结果是这样的：截图看起来像是iOS添加了一些偏移量到popover

我还尝试将modalPresentationStyle更改为overCurrentContext，但它变成了fullscreen。有没有办法使用当前的ViewController来做到这一点？（而不是手动将子视图添加到该位置）

Answer 1

如果我没理解错的话，我很少修改你的代码：

override func viewDidLoad() {
    super.viewDidLoad()
    let button = UIButton(frame: CGRect(x: 250, y: 250, width: 100, height: 100))
    button.backgroundColor = UIColor.red
    button.addTarget(self, action: #selector(popover), for: .touchUpInside)
    view.addSubview(button)
}

@objc func popover() {
    
    let ac = UIAlertController(title: "Hello!", message: "This is a test.", preferredStyle: .actionSheet)
    
    let popover = ac.popoverPresentationController
    popover?.sourceView = view
    popover?.sourceRect = CGRect(x: 32, y: 32, width: 100, height: 100)

    present(ac, animated: true)
}