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Parsing Cultural Specific Decimal and DateTime values in .NET

I have an ASP.NET MVC app that must work in both English and German. In one of my views, the user is inputting a decimal value and a date/time value.
// Get the price
string price = "1.23";
decimal priceValue = 0;
var allowedStyles = (NumberStyles.AllowDecimalPoint & NumberStyles.AllowThousands);
if (Decimal.TryParse(price, allowedStyles, CultureInfo.InvariantCulture, out priceValue))
{
model.Price = priceValue;
}
else
errors.Add("Please enter a valid price.");
// Parse the date
string date = "03/23/2015";
if (String.IsNullOrWhiteSpace(date) == false)
{
DateTime dateValue = DateTime.MinValue;
if (DateTime.TryParse(saleDate, out dateValue))
{
model.Date = dateValue;
}
else
errors.Add("Please enter a valid date.");
}
When the above code runs in the English culture, the Decimal.TryParse line returns false. When the code runs in the German culture, both the Decimal.TryParse and DateTime.TryParse lines return false. What am I doing wrong? How can I parse Decimal and DateTime values across cultures?

When the above code runs in the English culture, the Decimal.TryParse
line returns false
Because you are using bitwise AND with & operator and NumberStyles.AllowDecimalPoint & NumberStyles.AllowThousands generates NumberStyles.None which indicates no style for your element. From documentation;
Indicates that no style elements, such as leading or trailing white
space, thousands separators, or a decimal separator, can be present in
the parsed string. The string to be parsed must consist of integral
decimal digits only.
If you change & to | your Decimal.TryParse returns true.
When the code runs in the German culture, both the Decimal.TryParse
and DateTime.TryParse lines return false.
Same for Decimal.TryParse method. BUT, de-DE culture has , instead of . as a NumberDecimalSeparator. But it has . as a NumberGroupSeparator that's why it parses your 1.23 value as 123. It thinks this is a thousands separator, not a decimal separator.
For your DateTime.TryParse method, since you didn't tell us what is saleDate exactly, looks like it is not a standard date and time format for your CurrentCulture, that's why it returns false.
If you mean date instead of saleDate, that means MM/dd/yyyy is not a standard date and time format for your CurrentCulture and neither for de-DE culture.
You can use DateTime.TryParseExact or DateTime.ParseExact (preferable) method with a culture that has / as a DateSeparator like InvariantCulture like;
string date = "03/23/2015";
DateTime dt;
if(DateTime.TryParseExact(date, "MM/dd/yyyy", CultureInfo.InvariantCulture,
DateTimeStyles.None, out dt))
{
model.Date = dateValue;
}

You should not be using InvariantCulture for that. You should parsing using 1 culture at a time, then attempting the other if that fails.

Convert String to Double with Known Format

I need to convert a string back to a double, but the string is not always the same format. In one case it is "N0", in another "#,##", and yet another is currency "C0". The good thing is, I know what format the string is in as earlier in the process it was converted from double to string.
How can I convert back to a double. The numeric only values double.parse or Convert.ToDouble with ease, but the currency values do not.
string format = "{0:C0}";
double dollar = 1,234.00;
string dollarString = String.Format(format, doubleValue); // == "$1,234"
double newDollar = Convert.ToDouble(dollarString); // Fails
This last line is where the issue is. I'm assuming I need to use IFormatProvider or Culture or something, but I'm not exactly sure.
I cannot specifically reference the format is a Currency as the "format" isn't always a currency.
Ideas?

As I was typing this I came up with the following. Further feedback on whether this is a good way of doing it or if I might run into issues later.
double newDollar;
double.TryParse(dollarString, NumberStyles.Any, CultureInfo.CurrentCulture.NumberFormat, out newDollar);

If you're using CultureInfo.CurrentCulture make sure to you set the CurrentCulture of your thread.
Else it can end up in parsing it the wrong way (depending on the language settings on your computer).
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture("en-US");
Then you can safely use this:
double.TryParse(dollarString, NumberStyles.Any,
CultureInfo.CurrentCulture.NumberFormat, out newDollar);
Alternatively, you can create a function like this (To get the right format without setting the culture).
side note: In Switzerland, this could cause troubles because the euros can still be parsed.
So 5,05 (€) would successfully be parsed to 505 (CHF). Trust me, you don't want this to happen.
public static double GetDouble(string value, double defaultValue)
{
double numberToConvert;
if (!double.TryParse(value, System.Globalization.NumberStyles.Any,
CultureInfo.CurrentCulture, out numberToConvert) &&
!double.TryParse(value, System.Globalization.NumberStyles.Any,
CultureInfo.GetCultureInfo("en-US"), out numberToConvert) &&
!double.TryParse(value, System.Globalization.NumberStyles.Any,
CultureInfo.InvariantCulture, out numberToConvert))
{
numberToConvert= defaultValue;
}
return numberToConvert;
}

decimal.TryParse returns false

The input string in textbox is, say, $10.00 . I call
decimal result;
var a = decimal.TryParse(text, NumberStyles.AllowCurrencySymbol, cultureInfo, out result);
cultureInfo is known (en-US). Why does decimal.tryParse returns false?
Thank you.

The problem is you've allowed the currency symbol itself, but you've omitted other properties that are required to parse it correctly (decimal point, for example.) What you really want is NumberStyles.Currency:
decimal.TryParse("$10.00", NumberStyles.Currency, cultureInfo, out result);

Try this, you need to include NumberStyles.Number in the bitwise combination of values for the style argument:
decimal result;
var a = decimal.TryParse(text, NumberStyles.Number | NumberStyles.AllowCurrencySymbol, cultureInfo, out result);

You forgot to allow the decimal point, too:
decimal result;
var enUS = new System.Globalization.CultureInfo("en-US");
var a = decimal.TryParse("$10.00", System.Globalization.NumberStyles.AllowCurrencySymbol | System.Globalization.NumberStyles.AllowDecimalPoint , enUS, out result);
Console.WriteLine(enUS);
Console.WriteLine(a);
Console.WriteLine(result);

converting string to decimal in c#

I am having some problems converting string to decimal values with decimal.parse.
This is the line of code I have:
fixPrice = decimal.Parse(mItemParts.Groups["price"].Value.Replace("$", "").Replace(" ", "").Replace("usd", ""));
The value from which I am trying to convert is: '$779.99'
Then once the parsing to decimal happens, I am getting this value: 77999.
I would like to get 779.99 instead of 77999.
Thanks in advance, Laziale
Regex included: "#"\[^\""]+?)\""[^~]+?\]+?src=\""(?[^\""]+?)\""[^>]+?title=\""(?[^\""]+?)\""[^~]+?price\"">(?[^\<]+?)\<[^~]+?\(?[^\<]+?)\

I would use Decimal.TryParse():
decimal parsedDecimal = 0;
string yourCurrency = "$779.99";
bool didParse = Decimal.TryParse(yourCurrency,
NumberStyles.Currency,
new CultureInfo("en-US"), out parsedDecimal);
if(didParse) {
// Parse succeeded
}
else {
// Parse failed
}

It appears that you are running this in a culture where '.' is the group separator, and ',' is the decimal separator. To get around that, use the Parse overload that takes a CultureInfo:
fixPrice = decimal.Parse(stringExpression, CultureInfo.InvariantCulture);
Also look into the NumberStyles enum so you don't have to worry about currency signs yourself:
fixPrice = decimal.Parse(stringExpression, NumberStyles.Currency, new CultureInfo("en-US"));

Pass a CultureInfo instance of the culture you are parsing from.
CultureInfo inherits from IFormatProvider
edit:
Here is a sample for the conversion
Decimal.Parse(yourValue, NumberStyles.AllowCurrencySymbol |
NumberStyles.AllowDecimalPoint |
NumberStyles.AllowThousands,
CultureInfo.InvariantCulture);

This works for me:
string decStr = "$779.99";
CultureInfo ci = new CultureInfo("en-US");
decimal fixPrice = decimal.Parse(decStr, NumberStyles.Currency, ci);

How do I convert a string to a decimal, and format it for pretty output?

I want to convert "372551.40" to decimal. But I need to see it after converting this format 372.551,40.

To convert it to decimal, you can use:
decimal decimalValue = 0.0;
decimalValue = decimal.Parse("372551.40");
or
decimal.TryParse("372551.40", out decimalValue);
To display it in a specific format you can do:
CultureInfo tr = new CultureInfo("tr-TR");
string formattedValue = decimalValue.ToString("c", tr);
//result will be 372.551,40 YTL
formattedValue = decimalValue.ToString("0,0.00", tr);
//result will be 372.551,40

string value;
Decimal number;
value = "16,523,421";
if (!Decimal.TryParse(value,out number))
{
// set it to something if the "Value" is not a number
number = -1;
}

Do the following:
string s = "372551.40";
CultureInfo cultureInfo = CultureInfo.InvariantCulure; //Use relevant culture in which your number is formatted. In this case InvariantCulture would do.
decimal d;
bool succesful = Decimal.TryParse(s, NumberStyles.Number, cultureInfo, out d); //it will try to parse the string according to the specified culture.;
If you have a succesful parse, then d will store the numeric value represented by s as a decimal value which you can output into any formatted string and culture the ToString() or Format.String().
Note that if the culture in which the number represented by s is the current system culture, then you can use the TryParse(string s, out decimal d) overload where it is not necessary to specify NumberStyles and IFormatProvider.

Something like this?
string s = "372551.40";
decimal d;
if (decimal.TryParse(s, out d))
{
var culture = new CultureInfo("de-DE");
var result = d.ToString("0,0.00", culture);
// result is "372.551,40"
}
You can also use the current culture instead of hard-coding one like I did.
Hope this helps,
John

Use decimal.Parse() to make it a decimal. Then you have many formatting options.

The display as you mentioned is dependent on the culture setting.
Make your new CultureInfo and in the NumberFormat, you will have to modify some settings like Decimal Separator as , and Thousands Separator as . and provide this to the ToString method of the variable holding the decimal value.
This should display the value as 372.551,40

You can use .Replace
string string 1 = "372,551.40";
string1.Replace(",","");
decimalVal = System.Convert.ToDecimal(StringVal);
//shows 372551.40
You can always throw that into a for loop if you are playign with a ton of numbers.
You can find more in depth info and some examples on MSDN

The overload of decimal.Parse that takes an IFormatProvider will allow you to parse strings containing numbers with periods as decimal point symbols (in case the standard is a comma in your culture).
You can use ToString on the resulting decimal to format it with a comma by passing in an appropriate IFormatProvider. Both CulturInfo and NumberFormatInfo implement IFormatProvider.
You can get an instance of CultureInfo with the following code (this one is for English in Australia).
new CultureInfo("en-AU")
Also note that decimal.TryParse is a good alternative to the decimal.Parse method if you expect incorrectly formatted strings as it will allow you to handle them without an exception being raised.
The following code should give you the desired result (you wrote in one of the comments that the target system is SAP and that the culture is probably German (de-DE)).
var yourString = "372551.40";
var yourDecimal = decimal.Parse(yourString, CultureInfo.InvariantCulture);
var yourFormattedDecimal = yourDecimal.ToString(new CultureInfo("de-DE"));

From MSDN:
string value;
decimal number;
// Parse an integer with thousands separators.
value = "16,523,421";
number = Decimal.Parse(value);
Console.WriteLine("'{0}' converted to {1}.", value, number);
// Displays:
// 16,523,421' converted to 16523421.
Cheers

You can create custom NumberFormatInfo:
string s = "372551.40";
var dec = decimal.Parse(s, CultureInfo.InvariantCulture);
var nfi = new CultureInfo("en-US", false).NumberFormat;
nfi.NumberGroupSeparator = ".";
nfi.NumberDecimalSeparator = ",";
var res = dec.ToString("n", nfi);
var resDecimal = decimal.Parse(res, nfi);
Output is exactly what you need: 372.551,40