NSNumberCurrencyFormatter否定格式

Question

我遇到问题，如果您将我的应用中的货币更改为与区域设置不同的内容，我的应用会错误地显示负值，例如应用货币设置为£，locale设置为美国，我的负数显示为（$ 278.00）。我希望它显示 - £278.00。我使用以下格式编号：

// Get the currency from the user settings/preferences
NSString *currency = [[NSUserDefaults standardUserDefaults] objectForKey:CURRENCY_KEY];

// Set the format, currency and negative format so that we don't display the default (xx.xx)
NSNumberFormatter *numberCurrencyFormatter = [[NSNumberFormatter alloc] init];
[numberCurrencyFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
[numberCurrencyFormatter setCurrencySymbol:currency];

[numberCurrencyFormatter setCurrencyDecimalSeparator:[[NSLocale currentLocale] objectForKey:NSLocaleDecimalSeparator]];

if ([[[NSLocale currentLocale] objectForKey:NSLocaleDecimalSeparator] isEqualToString:DECIMAL]) {
    [numberCurrencyFormatter setCurrencyGroupingSeparator:COMMA];
    [numberCurrencyFormatter setNegativeFormat:[currency stringByAppendingString:@"-#,##0.00"]];
} else {
    [numberCurrencyFormatter setCurrencyGroupingSeparator:DECIMAL];
    [numberCurrencyFormatter setNegativeFormat:[currency stringByAppendingString:@"-#.##0,00"]];
}

return [numberCurrencyFormatter stringFromNumber:number];