Question

我正在将应用程序从ios 7升级到ios 8，而我遇到问题的一个方面是新的UIPopoverPresentationController。出于某种原因，每当我使用此类呈现视图控制器时，视图控制器不会出现在弹出框中，而是呈现为将其推入导航堆栈（占据整个屏幕）。我确定我错过了显而易见的内容，但在Apple的文档和众多Swift的答案之间，我错过了它。这是我的代码：

-(void)createAndSizePopover:(NSString*)tableName
{
    //Create the picklist
    self.pickListPopoverViewController = nil;
    //NOTE WSPickListViewController is a UIViewController
    self.pickListPopoverViewController = [[WSPickListViewController alloc] initWithNibName:nil bundle:nil withPickListItem:self.densityUnits andPickListTableName:tableName isSlimLine:YES];
    self.pickListPopoverViewController.showSearchBar = NO;
    self.pickListPopoverViewController.modalPresentationStyle = UIModalPresentationPopover;
    ((WSPickListViewController*)self.pickListPopoverViewController).pickListItemDelegate = self;

    //Size the popover
    NSInteger rowsCount = [self.pickListPopoverViewController.allObjects count];
    NSInteger singleRowHeight = 35;
    NSInteger totalRowsHeight = rowsCount * singleRowHeight;
    NSInteger fourRowsHeight = 6 * singleRowHeight;
    NSInteger height = (totalRowsHeight >= fourRowsHeight) ? fourRowsHeight : totalRowsHeight;

    CGFloat largestLabelWidth = 0;
    for (WSPickList* pickItem in self.pickListPopoverViewController.allObjects)
    {
        CGSize labelSize = [pickItem.name sizeWithAttributes:@{NSFontAttributeName: [UIFont fontWithName:@"HelveticaNeue" size:20.0], NSForegroundColorAttributeName : [UIColor blackColor]}];
        if (labelSize.width > largestLabelWidth)
        {
            largestLabelWidth = labelSize.width;
        }
    }

    CGFloat popoverWidth = largestLabelWidth + 50;

    [self.pickListPopoverViewController setPreferredContentSize:CGSizeMake(popoverWidth, height)];
}

-(void)showOrHidePopover:(id)sender withTableName:(NSString*)tableName
{
    //Show/Hide the popover
    if (self.popover != nil)
    {
        [self.pickListPopoverViewController dismissViewControllerAnimated:YES completion:nil];
        self.popover = nil;
        self.pickListPopoverViewController = nil;
        return;
    }
    else
    {
        [self createAndSizePopover:tableName];
    }

    [self presentViewController:self.pickListPopoverViewController animated:YES completion: nil];

    self.popover = self.pickListPopoverViewController.popoverPresentationController;        
    self.popover.permittedArrowDirections = UIPopoverArrowDirectionRight;
    self.popover.sourceView = sender;

    if ([sender isKindOfClass:[UIButton class]])
    {
        self.popover.sourceRect = ((UIButton*)sender).bounds;
    }
    else if ([sender isKindOfClass:[UICollectionViewCell class]])
    {
        self.popover.sourceRect = ((UICollectionViewCell*)sender).bounds;
    }
}

我可以在Objective-C或Swift中找到答案（因为无论如何我都需要学习）。提前感谢您提供的任何帮助！

Answer 1

经过几天的Google理论和测试理论，我终于在我的代码中发现了几个问题。

首先，在设置popoverPresentationController之前无法进行演示。我知道面对Apple的文档很苍白，甚至声称在设置popover控制器之前呈现视图控制器似乎“违反直觉”，但即使这仍然对我有用。

其次，我对adaptivePresentationStyleForPresentationController的实现：错了。我正在返回UIModalPresentationPopover，但我应该按照以下方式返回UIModalPresentationNone：

-(UIModalPresentationStyle)adaptivePresentationStyleForPresentationController:(UIPresentationController *)controller
{
    return UIModalPresentationNone;
}

希望这有助于其他人。

为什么UIPopoverPresentationController中的视图控制器会占用整个屏幕？

1 个答案: