弹出窗口不以按钮为中心

Question

我正在尝试将弹出框置于按钮的中央。我似乎无法弄清楚我可能哪里出错了。箭头不是位于按钮的中间，而是偏离中心一半的屏幕宽度。

 @IBAction func buttonClicked(sender: AnyObject){
    var popoverViewController = self.storyboard?.instantiateViewControllerWithIdentifier("ServiceOptions") as! ServiceOptionsPopover
    popoverViewController.delegate = self
    popoverViewController.modalPresentationStyle = .Popover
    popoverViewController.preferredContentSize   = CGSizeMake(300, 300)

    let popoverPresentationViewController = popoverViewController.popoverPresentationController

    popoverPresentationViewController?.permittedArrowDirections = .Up
    popoverPresentationViewController?.delegate = self
    popoverPresentationViewController?.sourceView = sender as! UIButton
    popoverPresentationViewController?.sourceRect = sender.frame

    presentViewController(popoverViewController, animated: true, completion: nil)
}

Answer 1

正确的方法是：

@IBAction func buttonClicked(sender: UIButton){
    var popoverViewController = UIViewController()
    popoverViewController.view.frame = CGRectMake(0,0, 300, 300)
    popoverViewController.view.backgroundColor = UIColor.redColor()
    popoverViewController.modalPresentationStyle = .Popover
    popoverViewController.preferredContentSize   = CGSizeMake(300, 300)

    let popoverPresentationViewController = popoverViewController.popoverPresentationController

    popoverPresentationViewController?.permittedArrowDirections = .Up
    popoverPresentationViewController?.sourceView = sender
    popoverPresentationViewController?.sourceRect = CGRectMake(0, 0, sender.bounds.width,sender.bounds.height) // see this line of code

    presentViewController(popoverViewController, animated: true, completion: nil)
}

Answer 2

问题是混淆框架和边界的初级问题：

popoverPresentationViewController?.sourceView = sender as! UIButton
popoverPresentationViewController?.sourceRect = sender.frame

不！你是说界限：

popoverPresentationViewController?.sourceView = sender as! UIButton
popoverPresentationViewController?.sourceRect = (sender as! UIButton).bounds

原因是 sourceRect 在 sourceView 的坐标 space 中给出 - 也就是说，如果您希望它是视图的矩形，则它是那个观点。

Answer 3

iOS 9. 在故事板中设置锚点：

...导致箭头未以锚点为中心：

要解决，请将此添加到 prepareForSegue:sender::

// Fixes popover anchor centering issue in iOS 9
if let popoverPresentationController = segue.destinationViewController.popoverPresentationController, sourceView = sender as? UIView {
  popoverPresentationController.sourceRect = sourceView.bounds
}

Answer 4

在我的例子中，问题有所不同，弹出窗口显示为具有自定义视图的 UIBarButtonItem。对于 iOS 11 如果您使用 UIBarButtonItem 的自定义视图，自定义视图需要自动布局友好。

有了这个类别，您可以快速应用约束。

UIView+NavigationBar.h

@interface UIView (NavigationBar)

    - (void)applyNavigationBarConstraints:(CGFloat)width height:(CGFloat)height;
    - (void)applyNavigationBarConstraintsWithCurrentSize;

@end

UIView+NavigationBar.m

#import "UIView+NavigationBar.h"

@implementation UIView (NavigationBar)

- (void)applyNavigationBarConstraints:(CGFloat)width height:(CGFloat)height
{
    if (width == 0 || height == 0) {
        return;
    }

    NSLayoutConstraint *heightConstraint = [NSLayoutConstraint constraintWithItem:self attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1 constant:height];
    NSLayoutConstraint *widthConstraint = [NSLayoutConstraint constraintWithItem:self attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1 constant:width];
    [heightConstraint setActive:TRUE];
    [widthConstraint setActive:TRUE];
}

- (void)applyNavigationBarConstraintsWithCurrentSize {
    [self applyNavigationBarConstraints:self.bounds.size.width height:self.bounds.size.height];
}

@end

那么你可以这样做：

UIButton *buttonMenu = [UIButton buttonWithType:UIButtonTypeCustom];
[buttonMenu setImage:[UIImage imageNamed:@"menu"] forState:UIControlStateNormal];
buttonMenu.frame = CGRectMake(0, 0, 44, 44);
[buttonMenu addTarget:self action:@selector(showMenu:) forControlEvents:UIControlEventTouchUpInside];

//Apply constraints 
[buttonMenu applyNavigationBarConstraintsWithCurrentSize];

UIBarButtonItem *menuBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:buttonMenu];

一旦您应用约束，弹出窗口就会在自定义视图上正确显示，例如，将警报显示为弹出窗口的代码是：

UIAlertController *controller = [UIAlertController alertControllerWithTitle:@"Menu" message:@"" preferredStyle:UIAlertControllerStyleActionSheet];
//Add actions ....

UIPopoverPresentationController *popController = [controller popoverPresentationController];
popController.sourceView = buttonMenu;
popController.sourceRect = buttonMenu.bounds;

[self presentViewController:controller animated:YES completion:nil];

弹出窗口不以按钮为中心

Popover doesn't center on button

ios

swift

uipopovercontroller