如何在 swift 中居中弹出概览

Question

我有以下代码来显示没有箭头的弹出视图（对话框），效果很好。唯一的问题是，对话框显示在左上角 (IPad)。我想让视图在屏幕上居中。

要在我的以下代码中更改或添加什么？ :

func show_help(){


    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let controller = storyboard.instantiateViewControllerWithIdentifier("Help") as! UIViewController

    controller.modalPresentationStyle = UIModalPresentationStyle.popover

    let popoverPresentationController = controller.popoverPresentationController

    // result is an optional (but should not be nil if modalPresentationStyle is popover)
    if let _popoverPresentationController = popoverPresentationController {

        // set the view from which to pop up
        _popoverPresentationController.sourceView = self.view;
        _popoverPresentationController.permittedArrowDirections = UIPopoverArrowDirection.allZeros;
        // present (id iPhone it is a modal automatic full screen)
        self.presentViewController(controller, animated: true, completion: nil)
    }

}

附加信息

在我看来，这与我的 viewcontroller 相关联，我这样设置首选尺寸：

override func viewDidLoad() {
        let dialogheigth:CGFloat = self.view.frame.height * 0.5;
        let dialogwidth:CGFloat = self.view.frame.width * 0.5;
        self.preferredContentSize = CGSizeMake(dialogwidth,dialogheigth);
}

Answer 1

在iOS8中，您不需要使用self.view.frame来计算宽度和高度。

您可以使用以下方式设置对话框的高度和宽度：

override func viewDidLoad() {
     var frameSize: CGPoint = CGPointMake(UIScreen.mainScreen().bounds.size.width*0.5, UIScreen.mainScreen().bounds.size.height*0.5)
     self.preferredContentSize = CGSizeMake(frameSize.x,frameSize.y);
}

已编辑：

您也可以设置contentSizeForViewInPopover如下：

self.contentSizeForViewInPopover = CGSizeMake(320.0, 360.0)

让我知道这有帮助吗？

Answer 2

您需要为弹出窗口提供源矩形。

来自 Apple 文档：源矩形是指定视图中用于锚定弹出框的矩形。将此属性与 sourceView 属性结合使用以指定弹出窗口的锚点位置。

在你的情况下，

_popoverPresentationController.sourceView = self.view;

添加：

_popoverPresentationController.sourceRect = CGRectMake(CGRectGetMidX(self.view.bounds), CGRectGetMidY(self.view.bounds),0,0)

它会成功的！

Answer 3

基本上包括三个步骤(iOS 8):

1.- Present the view:

比方说，您想显示一个自定义视图以请求用户评论。这里的函数 loadNibForRate() returns 是从其 nib 加载的 RateDialog 的一个实例, 但您可以在此处使用任何您希望找到 UIViewController

的方式

private static func presentCustomDialog(parent: RateDialogParent) -> Bool {
    /// Loads the rateDialog from its xib, handled this way for further customization if desired
      if let rateDialog = loadNibForRate() {
        rateDialog.modalPresentationStyle = UIModalPresentationStyle.Popover
        rateDialog.modalTransitionStyle = UIModalTransitionStyle.CrossDissolve
        let x = parent.view.center

        let sourceRectX : CGFloat
        //Here we check for the orientation of the device, just to know if we are on an iPad
        let maximumDim = max(UIScreen.mainScreen().bounds.height, UIScreen.mainScreen().bounds.width)
        if maximumDim == 1024 { //iPad
            sourceRectX = x.x
        }else {
            sourceRectX = 0
        }

        rateDialog.popoverPresentationController?.sourceView = parent.view
        rateDialog.popoverPresentationController?.permittedArrowDirections = UIPopoverArrowDirection.allZeros
        rateDialog.popoverPresentationController?.sourceRect = CGRectMake(sourceRectX, x.y, 0, 0)
        rateDialog.popoverPresentationController?.popoverLayoutMargins = UIEdgeInsetsMake(0, 0, 0, 0)
        rateDialog.popoverPresentationController?.delegate = parent

        rateDialogParent = parent

        callFunctionAsync() {
            parent.presentViewController(rateDialog, animated: true, completion: nil)
        }
        return true
    }
    return false
}

2.- If we rotate our device, then the popover will not know where to reposition itself, unless we have this on the parent RateDialogParent

public class RateDialogParent: UIViewController, UIPopoverPresentationControllerDelegate {
/**
This function guarantees that the RateDialog is alwas centered at parent, it locates the RateDialog's view by searching for its tag (-555)
 */
 public func popoverPresentationController(popoverPresentationController: UIPopoverPresentationController, willRepositionPopoverToRect rect: UnsafeMutablePointer<CGRect>, inView view: AutoreleasingUnsafeMutablePointer<UIView?>) {
    if popoverPresentationController.presentedViewController.view.tag == RateDialog.thisViewTag {
        let x = popoverPresentationController.presentingViewController.view.center
        let newRect = CGRectMake(x.x, x.y, 0, 0)
        rect.initialize(newRect)
    }
 }
}

3.- Your RateDialog should have a tag setted, this is just to avoid relocating unwanted popovers if there is more that one presented from your RateDialogParent

class RateDialog: UIViewController {
 @IBOutlet weak var reviewTitle: UILabel!
 @IBOutlet weak var reviewMessage : UILabel!
 @IBOutlet weak var cancelButtonTitle: UIButton!
 @IBOutlet weak var remindButtonTitle : UIButton!
 @IBOutlet weak var rateButtonTitle : UIButton!

    /// For being able to locate this view
 static let thisViewTag = -555

 override func viewDidLoad() {
    super.viewDidLoad()
    //sets the tag to identify this view
    self.view.tag = RateDialog.thisViewTag
 }
}

Answer 4

这是一个使用 Swift 3

的实现

let popover = storyboard?.instantiateViewController(withIdentifier: "popover") as! PopoverVC

    popover.modalPresentationStyle = UIModalPresentationStyle.popover
    popover.popoverPresentationController?.backgroundColor = UIColor.green
    popover.popoverPresentationController?.delegate = self

    popover.popoverPresentationController?.sourceView = self.view
    popover.popoverPresentationController?.sourceRect = CGRect(x: self.view.bounds.midX, y: self.view.bounds.midY, width: 0, height: 0)

    popover.popoverPresentationController?.permittedArrowDirections = UIPopoverArrowDirection(rawValue: 0)

    self.present(popover, animated: true)

基于伊斯特万的

Answer 5

Swift 3 (Xcode 8, iOS 9) 的另一种方式是这样的：

从某处调用：

self.performSegue(withIdentifier: "showPopupSegue", sender: yourButton)

在触发 segue 之前调用的函数：

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if let popoverPresentationController = segue.destination.popoverPresentationController {
        let controller = popoverPresentationController
        controller.permittedArrowDirections = UIPopoverArrowDirection(rawValue: 0)
        controller.sourceView = self.view
        controller.sourceRect = CGRect(x: UIScreen.main.bounds.width * 0.5 - 200, y: UIScreen.main.bounds.height * 0.5 - 100, width: 400, height: 200)
        segue.destination.preferredContentSize=CGSize(width: 400, height: 200)
    }
}

记得将故事板 segue 的 Kind 属性设置为 "Present as Popover" 并将 Anchor 属性设置为您之前的视图控制器中的任何视图。

Answer 6

Swift 4 实施：

popover.popoverPresentationController?.sourceRect = CGRect(x: view.center.x, y: view.center.y, width: 0, height: 0)
popover.popoverPresentationController?.sourceView = view
popover.popoverPresentationController?.permittedArrowDirections = UIPopoverArrowDirection(rawValue: 0)

Answer 7

如果对任何人有帮助，我已经在 UIViewController 上创建了一个扩展

extension UIViewController{
    func configureAsPopoverAndPosition(withWidthRatio widthRatio:CGFloat,
                                       heightRatio:CGFloat){
        modalPresentationStyle = .popover
        let screenWidth = UIScreen.main.bounds.width
        let screenHeight = UIScreen.main.bounds.height
        let popover = popoverPresentationController
        popover?.sourceView = self.view

        popover?.permittedArrowDirections = [UIPopoverArrowDirection(rawValue: 0)]
        preferredContentSize = CGSize(width: (screenWidth * widthRatio),
                                      height: (screenHeight * heightRatio))

        popover?.sourceRect = CGRect(x: view.center.x,
                                     y: view.center.y,
                                     width: 0,
                                     height: 0)
    }
}

用法：

if UIDevice.current.userInterfaceIdiom == .pad{
                    yourViewController.configureAsPopoverAndPosition(withWidthRatio: 0.7 /*Make view controller width 70 % of screen width*/,
                                                                        heightRatio: 0.7/*Make view controller height 70 % of screen height*/)
                }

这将在屏幕中央显示弹出窗口。

Answer 8

Swift 中心 Popover 控制器的 4 个实现

let navigationController = UINavigationController(rootViewController: controller)

 navigationController.modalPresentationStyle = .popover      
 navigationController.modalPresentationStyle = UIModalPresentationStyle.popover
 let popover = navigationController.popoverPresentationController
 controller.preferredContentSize = CGSize(width:500,height:600) //manage according to Device like iPad/iPhone
 popover?.delegate = self
 popover?.sourceView = self.view
 popover?.sourceRect = CGRect(x: view.center.x, y: view.     .y, width: 0, height: 0)
 popover?.permittedArrowDirections = UIPopoverArrowDirection(rawValue: 0)

 self.present(navigationController, animated: true, completion: nil)

Answer 9

Swift 4.1

这是简单的解决方案：

取一个public变量var popover

var popover: UIPopoverPresentationController?

将 YourViewController 作为弹出窗口，使用下面提到的 popover?.sourceRect。

let storyboard: UIStoryboard = UIStoryboard(name: "YOUR_STORYBOARD", bundle: nil)
let vc = storyboard.instantiateViewController(withIdentifier: "YOUR_IDENTIFIER") as! YourViewController
let navController = UINavigationController(rootViewController: vc)
navController.modalPresentationStyle = UIModalPresentationStyle.popover
popover = yourController.popoverPresentationController!
popover?.sourceRect = CGRect(x: UIScreen.main.bounds.midX, y: UIScreen.main.bounds.midY, width: 0, height: 0)
popover?.sourceView = self.view
popover?.delegate = self
popover?.permittedArrowDirections = UIPopoverArrowDirection(rawValue: 0)
vc.preferredContentSize = CGSize(width: width, height: height)
self.present(navController, animated: true, completion: nil)

使用 viewWillTransition 进行横向和纵向视图转换。

override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
     super.viewWillTransition(to: size, with: coordinator)
     popover?.sourceRect = CGRect(x: UIScreen.main.bounds.midX, y: UIScreen.main.bounds.midY, width: 0, height: 0)
}

这将使您的弹出窗口在横向和纵向屏幕上都居中对齐。 iPad.

使用拆分视图时更加灵活

Answer 10

添加下面提到的代码行使其居中。

popoverController.popoverPresentationController?.sourceView = view

popoverController.popoverPresentationController?.sourceRect = view.bounds

如何在 swift 中居中弹出概览

how to center a popoverview in swift

modal-dialog

uipopovercontroller

ios

swift

Swift 4.1