我正在尝试在我的应用上创建一个按钮，按下该按钮会询问用户是否要通过拍摄或从库中选择现有照片来添加图片。在过去的几天里，我一直在搜索这些代码，我将这些代码拼凑在一起，并在本网站上提出了一些其他问题。我在Xcode中有这个，并将它连接到底栏按钮。当我运行模拟器并按下按钮时，应用程序冻结或崩溃。任何想法为什么会发生这种情况？
-(IBAction)showAlertAction:(id)sender
{
UIAlertController * alertController = [UIAlertController alertControllerWithTitle: nil
message: nil
preferredStyle: UIAlertControllerStyleActionSheet];
[alertController addAction: [UIAlertAction actionWithTitle: @"Take Photo" style: UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
picker = [[UIImagePickerController alloc]init];
picker.delegate = self;
[picker setSourceType:UIImagePickerControllerSourceTypeCamera];
[self presentViewController: picker animated: YES completion:NULL];
}]];
[alertController addAction: [UIAlertAction actionWithTitle: @"Choose Existing Photo" style: UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
picker2 = [[UIImagePickerController alloc]init];
picker2.delegate = self;
[picker2 setSourceType:UIImagePickerControllerSourceTypePhotoLibrary];
[self presentViewController: picker2 animated: YES completion:NULL];
}]];
alertController.modalPresentationStyle = UIModalPresentationPopover;
UIView *senderView = (UIView *) sender;
UIPopoverPresentationController * popover = alertController.popoverPresentationController;
popover.permittedArrowDirections = UIPopoverArrowDirectionUp;
popover.sourceView = senderView;
popover.sourceRect = senderView.bounds;
[self presentViewController: alertController animated: YES completion: nil];
}
以下是调试部分中给出的错误...
2015-07-08 10:37:13.162 LED Audit[6011:282032] -[UIBarButtonItem bounds]: unrecognized selector sent to instance 0x7b658770
2015-07-08 10:37:13.518 LED Audit[6011:282032] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIBarButtonItem bounds]: unrecognized selector sent to instance 0x7b658770'
*** First throw call stack:
(
0 CoreFoundation 0x008b9746 __exceptionPreprocess + 182
1 libobjc.A.dylib 0x00542a97 objc_exception_throw + 44
2 CoreFoundation 0x008c1705 -[NSObject(NSObject) doesNotRecognizeSelector:] + 277
3 CoreFoundation 0x00808287 ___forwarding___ + 1047
4 CoreFoundation 0x008baede __forwarding_prep_1___ + 14
5 LED Audit 0x000570ea -[PictureViewController showAlertAction:] + 1130
6 libobjc.A.dylib 0x005587cd -[NSObject performSelector:withObject:withObject:] + 84
7 UIKit 0x00c79a90 -[UIApplication sendAction:to:from:forEvent:] + 99
8 UIKit 0x00fffbba -[UIBarButtonItem(UIInternal) _sendAction:withEvent:] + 139
9 libobjc.A.dylib 0x005587cd -[NSObject performSelector:withObject:withObject:] + 84
10 UIKit 0x00c79a90 -[UIApplication sendAction:to:from:forEvent:] + 99
11 UIKit 0x00c79a22 -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 64
12 UIKit 0x00dba18a -[UIControl sendAction:to:forEvent:] + 69
13 UIKit 0x00dba5a7 -[UIControl _sendActionsForEvents:withEvent:] + 598
14 UIKit 0x00db9811 -[UIControl touchesEnded:withEvent:] + 660
15 UIKit 0x00cd1cfa -[UIWindow _sendTouchesForEvent:] + 874
16 UIKit 0x00cd27d6 -[UIWindow sendEvent:] + 792
17 UIKit 0x00c906d1 -[UIApplication sendEvent:] + 242
18 UIKit 0x00ca0b08 _UIApplicationHandleEventFromQueueEvent + 21484
19 UIKit 0x00c74337 _UIApplicationHandleEventQueue + 2300
20 CoreFoundation 0x007db06f __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 15
21 CoreFoundation 0x007d0b7d __CFRunLoopDoSources0 + 253
22 CoreFoundation 0x007d00d8 __CFRunLoopRun + 952
23 CoreFoundation 0x007cfa5b CFRunLoopRunSpecific + 443
24 CoreFoundation 0x007cf88b CFRunLoopRunInMode + 123
25 GraphicsServices 0x03b1f2c9 GSEventRunModal + 192
26 GraphicsServices 0x03b1f106 GSEventRun + 104
27 UIKit 0x00c78106 UIApplicationMain + 1526
28 LED Audit 0x00058d9a main + 138
29 libdyld.dylib 0x02c45ac9 start + 1
30 ??? 0x00000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
答案 0 :(得分：1)
您不应该使用条形按钮项作为视图，它不是。修复非常简单。
UIPopoverPresentationController * popover = alertController.popoverPresentationController;
popover.permittedArrowDirections = UIPopoverArrowDirectionUp;
popover.barButtonItem = sender;