Question

我正在尝试创建一个自定义的简短菜单，该菜单从屏幕底部向上滑动并停留在底部（例如iOS共享表）。我很难弄清楚该怎么做。我尝试将视图控制器呈现为模式并设置首选的内容大小，但仍将其呈现为全屏显示。如何呈现类似模式的简短叠加层？

Answer 1

您可以使用UIPresentationController和UIViewControllerTransitioningDelegate。

这里是几行代码的起点：

UIViewControllerTransitioningDelegate

private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
{ 
    decimal accNo = Convert.ToDecimal(dataGridView1.Rows[e.RowIndex].Cells[0].Value);
    var item = db.UserAccount.Where(a => a.AccountNo == accNo).FirstOrDefault(); 

    txtAccountNo.Text = item.AccountNo.ToString();

    txtFirstName.Text = item.FirstName;
    txtLastName.Text = item.LastName;
    txtAddressUpNew.Text = item.Address.ToString();
 }

UIPresentationController

class OverlayTransitioningDelegate: NSObject, UIViewControllerTransitioningDelegate {

    func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController? {
        return OverlayPresentationController(presentedViewController:presented, presenting:presenting)
    }

}

如何命名

class OverlayPresentationController: UIPresentationController {

    private let dimmedBackgroundView = UIView()
    private let height: CGFloat = 200.0

    override init(presentedViewController: UIViewController, presenting presentingViewController: UIViewController?) {
        super.init(presentedViewController: presentedViewController, presenting: presentingViewController)
        let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(backgroundTapped))
        self.dimmedBackgroundView.addGestureRecognizer(tapGestureRecognizer)
    }

    override var frameOfPresentedViewInContainerView: CGRect {
        var frame =  CGRect.zero
        if let containerBounds = containerView?.bounds {
            frame = CGRect(x: 0,
                           y: containerBounds.height - height,
                           width: containerBounds.width,
                           height: height)
        }
        return frame
    }

    override func presentationTransitionWillBegin() {
        if let containerView = self.containerView, let coordinator = presentingViewController.transitionCoordinator {
            containerView.addSubview(self.dimmedBackgroundView)
            self.dimmedBackgroundView.backgroundColor = .black
            self.dimmedBackgroundView.frame = containerView.bounds
            self.dimmedBackgroundView.alpha = 0
            coordinator.animate(alongsideTransition: { _ in
                self.dimmedBackgroundView.alpha = 0.5
            }, completion: nil)
        }
    }

    override func dismissalTransitionDidEnd(_ completed: Bool) {
        self.dimmedBackgroundView.removeFromSuperview()
    }

    @objc private func backgroundTapped() {
       self.presentedViewController.dismiss(animated: true, completion: nil)
    }


}

演示

OverlayViewController是普通的ViewController。在这里，我使用了丑陋的绿色背景色，以便于识别叠加层。

如何创建一个简短的模式叠加层（如iOS共享表菜单）？

1 个答案: