[問題] 兩個UIAlertController時會閃退

[KeyBoardKill (✩鍵✩盤✩戮✩)]

各位好，我是學Swift不到一個禮拜的新手，今天嘗試更改別人的程式碼，我嘗試將Alert
button 增加成兩個，在iPhone上是正常的，但iPad會閃退，上網查詢是因爲記憶體位址
導致...但寫的看不懂，我應該怎麼去解決它呢？感謝指點

https://ideone.com/yZyAId

這是我其中的Code & alert log

2018-06-08 15:12:17.607567+0800 QRCodeReader[519:108687] [MC] System group container for systemgroup.com.apple.configurationprofiles path is /private/var/containers/Shared/SystemGroup/systemgroup.com.apple.configurationprofiles
2018-06-08 15:12:17.610165+0800 QRCodeReader[519:108687] [MC] Reading from public effective user settings.
2018-06-08 15:12:25.936288+0800 QRCodeReader[519:108687] *** Terminating app due to uncaught exception 'NSGenericException', reason: 'Your application has presented a UIAlertController (<UIAlertController: 0x142055000>) of style UIAlertControllerStyleActionSheet. The modalPresentationStyle of a UIAlertController with this style is UIModalPresentationPopover. You must provide location information for this popover through the alert controller's popoverPresentationController. You must provide either a
sourceView and sourceRect or a barButtonItem.  If this information is not known when you present the alert controller, you may provide it in the UIPopoverPresentationControllerDelegate method -prepareForPopoverPresentation.'
*** First throw call stack:
(0x182caed8c 0x181e685ec 0x18d4edef4 0x18cd44d58 0x18cd42f2c 0x18cca2884 0x18cc98958 0x18cb7d51c 0x182c56910 0x182c54238 0x182c54884 0x182b74da8 0x184b59020 0x18cb91758 0x100b79678 0x182605fc0)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)

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※ 編輯: KeyBoardKill (180.217.187.172), 06/08/2018 15:41:14
→ Blueshiva: *** Terminating app 那行英文看懂就好了...
謝謝指點^^我使用了popoverPresentationController來解決
※ 編輯: KeyBoardKill (180.217.187.172), 06/08/2018 16:01:06
推 tentenlee: 另外 其實現在不用canOpen 能開他自己會開 不會crash了
→ tentenlee: 以前要加是因為不能開 你去開 他就直接crash了
→ shinrenpan: UIAlertController 在iPhone 與 iPad 下 present 的
→ shinrenpan: 方式有所不同.