当 UITextField 包含货币符号时，NSDecimalNumber 数学运算导致应用程序崩溃

Question

我正在使用以下代码尝试基于两个文本字段执行简单的数学运算。问题是文本字段中有货币符号，它会导致 NSDecimalNumber 崩溃，如果我的文本字段在字符串中没有货币符号，它工作正常。

我尝试添加第二个 currencyFormatter 以将货币设置为空白，但我不知道如何使用它。

- (IBAction)transactionDetailViewQtyTxt_EditDidEnd:(id)sender {
    NSNumberFormatter *currencyFormatter = [[NSNumberFormatter alloc] init];
    [currencyFormatter setNumberStyle: NSNumberFormatterCurrencyStyle];
    [currencyFormatter setCurrencySymbol:[NWTillHelper getCurrencySymbol]];

    NSNumberFormatter *currencyFormatter2 = [[NSNumberFormatter alloc] init];
    [currencyFormatter2 setNumberStyle: NSNumberFormatterDecimalStyle];
    [currencyFormatter2 setCurrencySymbol:@""];

    _transactionDetailViewSumTxt.text = [currencyFormatter stringFromNumber:[[NSDecimalNumber decimalNumberWithString:_transactionDetailViewPriceTxt.text] decimalNumberByMultiplyingBy:[NSDecimalNumber decimalNumberWithString:_transactionDetailViewQtytxt.text]]];
}

下面是崩溃日志

2016-11-30 21:17:37.913 NWMobileTill[2048:52396] *** Terminating app due to uncaught exception 'NSDecimalNumberOverflowException', reason: 'NSDecimalNumber overflow exception'
*** First throw call stack:
(
    0   CoreFoundation                      0x000000010e26234b __exceptionPreprocess + 171
    1   libobjc.A.dylib                     0x000000010d8a621e objc_exception_throw + 48
    2   CoreFoundation                      0x000000010e2cb265 +[NSException raise:format:] + 197
    3   Foundation                          0x000000010d4d0917 -[NSDecimalNumberHandler exceptionDuringOperation:error:leftOperand:rightOperand:] + 193
    4   Foundation                          0x000000010d4cf761 _checkErrorAndRound + 65
    5   Foundation                          0x000000010d4cfa31 -[NSDecimalNumber decimalNumberByMultiplyingBy:withBehavior:] + 159
    6   NWMobileTill                        0x000000010d28a6d8 -[TransactionDetailView transactionDetailViewQtyTxt_EditDidEnd:] + 440
    7   UIKit                               0x000000010e6875b8 -[UIApplication sendAction:to:from:forEvent:] + 83
    8   UIKit                               0x000000010e80cedd -[UIControl sendAction:to:forEvent:] + 67
    9   UIKit                               0x000000010e80d1f6 -[UIControl _sendActionsForEvents:withEvent:] + 444
    10  UIKit                               0x000000010f19a6f8 -[UITextField _resignFirstResponder] + 313
    11  UIKit                               0x000000010e89d054 -[UIResponder _finishResignFirstResponder] + 286
    12  UIKit                               0x000000010f19a4e6 -[UITextField _finishResignFirstResponder] + 49
    13  UIKit                               0x000000010e89d103 -[UIResponder resignFirstResponder] + 140
    14  UIKit                               0x000000010f19a3b5 -[UITextField resignFirstResponder] + 136
    15  UIKit                               0x000000010e89cd93 -[UIResponder becomeFirstResponder] + 358
    16  UIKit                               0x000000010e736151 -[UIView(Hierarchy) becomeFirstResponder] + 138
    17  UIKit                               0x000000010f199280 -[UITextField becomeFirstResponder] + 51
    18  UIKit                               0x000000010ebd695f -[UITextInteractionAssistant(UITextInteractionAssistant_Internal) setFirstResponderIfNecessary] + 206
    19  UIKit                               0x000000010ebda177 -[UITextInteractionAssistant(UITextInteractionAssistant_Internal) oneFingerTap:] + 3823
    20  UIKit                               0x000000010ebc7e41 -[UIGestureRecognizerTarget _sendActionWithGestureRecognizer:] + 57
    21  UIKit                               0x000000010ebcfbe0 _UIGestureRecognizerSendTargetActions + 109
    22  UIKit                               0x000000010ebcd6af _UIGestureRecognizerSendActions + 227
    23  UIKit                               0x000000010ebcc93b -[UIGestureRecognizer _updateGestureWithEvent:buttonEvent:] + 891
    24  UIKit                               0x000000010ebb8a0e _UIGestureEnvironmentUpdate + 1395
    25  UIKit                               0x000000010ebb8453 -[UIGestureEnvironment _deliverEvent:toGestureRecognizers:usingBlock:] + 521
    26  UIKit                               0x000000010ebb7636 -[UIGestureEnvironment _updateGesturesForEvent:window:] + 286
    27  UIKit                               0x000000010e6f63b9 -[UIWindow sendEvent:] + 3989
    28  UIKit                               0x000000010e6a363f -[UIApplication sendEvent:] + 371
    29  UIKit                               0x000000010ee9571d __dispatchPreprocessedEventFromEventQueue + 3248
    30  UIKit                               0x000000010ee8e3c7 __handleEventQueue + 4879
    31  CoreFoundation                      0x000000010e207311 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
    32  CoreFoundation                      0x000000010e1ec59c __CFRunLoopDoSources0 + 556
    33  CoreFoundation                      0x000000010e1eba86 __CFRunLoopRun + 918
    34  CoreFoundation                      0x000000010e1eb494 CFRunLoopRunSpecific + 420
    35  GraphicsServices                    0x0000000112512a6f GSEventRunModal + 161
    36  UIKit                               0x000000010e685964 UIApplicationMain + 159
    37  NWMobileTill                        0x000000010d28869f main + 111
    38  libdyld.dylib                       0x000000011042d68d start + 1
    39  ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

Answer 1

为什么不先去掉货币符号呢？

NSString * numberNoCurrency = [_transactionDetailViewPriceTxt.text stringByReplacingOccurrencesOfString:@"$" withString:@""];

然后将该字符串提供给您的十进制转换以进行乘法运算。

Answer 2

您可能不想假设一个 $ 符号，但想去除除数字和小数（在某些地区可能是逗号）之外的所有内容。

NSMutableCharacterSet* numbers = [NSMutableCharacterSet decimalDigitCharacterSet];
[numbers addCharactersInString:[[NSLocale currentLocale] objectForKey:NSLocaleDecimalSeparator]];
NSCharacterSet* trim = [numbers invertedSet];

NSString* result = [[string componentsSeparatedByCharactersInSet:trim] componentsJoinedByString:@""];

当 UITextField 包含货币符号时，NSDecimalNumber 数学运算导致应用程序崩溃

NSDecimalNumber math operation causes app to crash when UITextField includes currency symbol

nsdecimalnumber

ios