当我使用iOS 8时，popover正在崩溃应用程序。 这是我编写的代码，当用户选择popover时，它就在方法中：
- (IBAction) onSelectingDefect:(id)sender
{
if ([description isFirstResponder]) {
[self hideKeyBoard];
return;
}
UIButton *button = (UIButton*)(sender);
UIButton *doneSelectingStatusButton = [UIButton buttonWithType:UIButtonTypeCustom];
doneSelectingStatusButton.frame = CGRectMake(85, 223, 149, 32);
[doneSelectingStatusButton setTintColor:[UIColor blackColor]];
[doneSelectingStatusButton setTitle:@"Done" forState:UIControlStateNormal];
[doneSelectingStatusButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[doneSelectingStatusButton setBackgroundImage:[UIImage imageNamed:@"cancel_button02.png"] forState:UIControlStateNormal];
[doneSelectingStatusButton addTarget:self action:@selector(onPickerSelection:) forControlEvents:UIControlEventTouchUpInside];
UIPickerView *pickerView = [[UIPickerView alloc] initWithFrame:CGRectMake(0, 0, 320, 216)];
pickerView.showsSelectionIndicator = YES;
pickerView.delegate = self;
pickerView.dataSource = self;
BOOL isNill = TRUE;
int i;
for(i=0; i<[tableData count]; i++)
{
if([selectedPickerText isEqualToString:[tableData objectAtIndex:i]])
{
isNill = FALSE;
break;
}
}
if(isNill)
{
[pickerView selectRow:0 inComponent:0 animated:YES]; //Orig
//self.selectedPickerText = [tableData objectAtIndex:0];
self.selectedPickerText = [tableData objectAtIndex:0];
}
else
[pickerView selectRow:i inComponent:0 animated:YES];//Orig
UIView *containerView = [[UIView alloc] initWithFrame:CGRectMake(0,0, 320, 255)];
[containerView addSubview:doneSelectingStatusButton];
[containerView addSubview:pickerView];
UIViewController *pickerViewController = [[UIViewController alloc] init];
CGRect myRect = button.frame;
myRect.origin.x += 10;
myRect.origin.y += 10;
selectionPopover = [[UIPopoverController alloc] initWithContentViewController:pickerViewController];
((AppDelegate*) [UIApplication sharedApplication].delegate).secondPopOver = selectionPopover;
selectionPopover.delegate =self;
selectionPopover.popoverContentSize = CGSizeMake(320, 255);
[selectionPopover presentPopoverFromRect:selectDefect.frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES]; //Error iOS8
pickerViewController.view = containerView;
[containerView release];
[pickerView release];
[pickerViewController release];
}
这是我得到的错误：
2014-11-04 20:01:30.740 Service360[447:5288] -[UITextField length]: unrecognized selector sent to instance 0x7f0d6520
2014-11-04 20:01:30.743 Service360[447:5288] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UITextField length]: unrecognized selector sent to instance 0x7f0d6520'
*** First throw call stack:
(
0 CoreFoundation 0x0321f946 __exceptionPreprocess + 182
1 libobjc.A.dylib 0x02d01a97 objc_exception_throw + 44
2 CoreFoundation 0x032275c5 -[NSObject(NSObject) doesNotRecognizeSelector:] + 277
3 CoreFoundation 0x031703e7 ___forwarding___ + 1047
4 CoreFoundation 0x0316ffae _CF_forwarding_prep_0 + 14
5 CoreFoundation 0x03108d26 CFStringAppend + 374
6 CoreFoundation 0x0310684a __CFStringAppendFormatCore + 11754
7 CoreFoundation 0x031fc5f5 _CFStringCreateWithFormatAndArgumentsAux2 + 245
8 Foundation 0x028b7697 -[NSPlaceholderString initWithFormat:locale:arguments:] + 159
9 Foundation 0x028baf42 +[NSString stringWithFormat:] + 89
10 UIKit 0x0183dd34 -[UIViewController _presentViewController:withAnimationController:completion:] + 2825
11 UIKit 0x018405d2 __62-[UIViewController presentViewController:animated:completion:]_block_invoke + 345
12 UIKit 0x01840424 -[UIViewController presentViewController:animated:completion:] + 224
13 UIKit 0x01db0791 -[UIPopoverController _presentShimmedPopoverFromRect:inView:permittedArrowDirections:animated:] + 217
14 UIKit 0x01db0991 -[UIPopoverController presentPopoverFromRect:inView:permittedArrowDirections:animated:] + 355
15 Service360 0x00369b52 -[POVendorFeedbackViewController onSelectingDefect:] + 2770
16 libobjc.A.dylib 0x02d177cd -[NSObject performSelector:withObject:withObject:] + 84
17 UIKit 0x016da23d -[UIApplication sendAction:to:from:forEvent:] + 99
18 UIKit 0x016da1cf -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 64
19 UIKit 0x0180de86 -[UIControl sendAction:to:forEvent:] + 69
20 UIKit 0x0180e2a3 -[UIControl _sendActionsForEvents:withEvent:] + 598
21 UIKit 0x0180d50d -[UIControl touchesEnded:withEvent:] + 660
22 UIKit 0x0172a60a -[UIWindow _sendTouchesForEvent:] + 874
23 UIKit 0x0172b0e5 -[UIWindow sendEvent:] + 791
24 UIKit 0x016f0549 -[UIApplication sendEvent:] + 242
25 Service360 0x00068f22 -[MyApplication sendEvent:] + 178
26 UIKit 0x0170037e _UIApplicationHandleEventFromQueueEvent + 20690
27 UIKit 0x016d4b19 _UIApplicationHandleEventQueue + 2206
28 CoreFoundation 0x031431df __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 15
29 CoreFoundation 0x03138ced __CFRunLoopDoSources0 + 253
30 CoreFoundation 0x03138248 __CFRunLoopRun + 952
31 CoreFoundation 0x03137bcb CFRunLoopRunSpecific + 443
32 CoreFoundation 0x031379fb CFRunLoopRunInMode + 123
33 GraphicsServices 0x044b424f GSEventRunModal + 192
34 GraphicsServices 0x044b408c GSEventRun + 104
35 UIKit 0x016d88b6 UIApplicationMain + 1526
36 Service360 0x0006793f main + 159
37 libdyld.dylib 0x077a7ac9 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
导致应用崩溃的行是：
[selectionPopover presentPopoverFromRect:selectDefect.frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES]; //Error iOS8
导致此错误的问题是什么？该应用程序在iOS的早期版本或早期版本中运行良好。
答案 0 :(得分：0)
某处你正在获得文本字段的长度。文本字段不存在或者您的方式错误。正确的方法是 [textfield.text length] ，而不是 [textfield length] 。