我有一个简单的textField，提示用户用英语回答。 为了强制键盘以英文显示，我将其设置为TypeURL，如下所示：
textField.autocorrectionType = UITextAutocorrectionTypeNo;
textField.spellCheckingType = UITextSpellCheckingTypeNo;
textField.autocapitalizationType = UITextAutocapitalizationTypeNone;
textField.keyboardType = UIKeyboardTypeURL;
[textField setReturnKeyType:UIReturnKeyDone];
我不断收到日本用户（所有运行iOS 7）的getFlickString崩溃报告，但我自己无法重现。 getFlickString似乎是一个私有的UIKit方法。
有什么想法吗？
提前感谢大家的帮助！
Fatal Exception: NSRangeException NSRangeException *** -[__NSArrayM objectAtIndex:]: index 4294967295 beyond bounds [0 .. 4] raw
0 CoreFoundation __exceptionPreprocess + 130
1 libobjc.A.dylib objc_exception_throw + 38
2 CoreFoundation -[__NSArrayM objectAtIndex:] + 232
3 UIKit getFlickString + 46
4 UIKit -[UIKeyboardLayoutStar(UIKeyboardLayoutJapanese50OnFlick) flickStringForInputKey:direction:] + 164
5 UIKit -[UIKeyboardLayoutStar completeRetestForTouchUp:timestamp:interval:executionContext:] + 2818
6 UIKit -[UIKeyboardLayoutStar touchUp:executionContext:] + 1474
7 UIKit -[UIKeyboardLayoutStarAccessibility(SafeCategory) touchUp:executionContext:] + 42
8 UIKit __28-[UIKeyboardLayout touchUp:]_block_invoke + 224
9 UIKit -[UIKeyboardTaskQueue continueExecutionOnMainThread] + 352
10 UIKit -[UIKeyboardLayout touchUp:] + 236
11 UIKit -[UIKeyboardLayout touchesEnded:withEvent:] + 324
12 UIKit -[UIWindow _sendTouchesForEvent:] + 528
13 UIKit -[UIWindow sendEvent:] + 832
14 UIKit -[UIApplication sendEvent:] + 196
15 UIKit _UIApplicationHandleEventQueue + 7116