显示UIPopOverPresentationController时崩溃

Question

*由于未捕获的异常'NSGenericException‘而终止应用程序，原因：'UIPopoverPresentationController (<_UIAlertControllerActionSheetRegularPresentationController: 0x1a56bd90>)应在演示文稿发生前设置非nil sourceView或barButtonItem。’

Answer 1

self.dismissViewControllerAnimated(true, completion: nil)
        let textToShare:String = "Lets have a chat!";
        let activityVC:UIActivityViewController = UIActivityViewController(activityItems: [textToShare], applicationActivities: nil)
        let excludeActivities = [UIActivityTypeAirDrop, UIActivityTypePrint, UIActivityTypeSaveToCameraRoll, UIActivityTypeAssignToContact, UIActivityTypePostToFlickr, UIActivityTypePostToTencentWeibo, UIActivityTypePostToVimeo, UIActivityTypePostToTencentWeibo]
        activityVC.excludedActivityTypes = excludeActivities
        activityVC.modalPresentationStyle =  UIModalPresentationStyle.FormSheet
 presentViewController(activityVC, animated: true, completion: nil)

Answer 2

我修改了下面的代码，并找到了解决方案。

if (DeviceType.IS_IPAD == false)
{
    presentViewController(activityVC, animated: true, completion: nil)
}else {
    // Change Rect to position Popover
    let popUp = UIPopoverController(contentViewController: activityVC)
    popUp.presentPopoverFromRect(CGRectZero, inView: self.view, permittedArrowDirections: UIPopoverArrowDirection.Any, animated: true)
}