This overload of the ulong.Parse(string, IFormatProvider) method is typically used to convert text that can be formatted in a variety of ways to a ulong value. For example, it can be used to convert the text entered by a user into an HTML text box to a numeric value.

The s parameter contains a number of the form:

[ws][sign]digits[ws]

Items in square brackets ([ and ]) are optional. The following table describes each element.

ws	Optional white space.
sign	An optional positive sign, or a negative sign if s represents the value zero.
digits	A sequence of digits ranging from 0 to 9.

The s parameter is interpreted using the System.Globalization.NumberStyles.Integer style. In addition to the unsigned integer value's decimal digits, only leading and trailing spaces along with a leading sign is allowed. (If the negative sign is present, s must represent a value of zero, or the method throws an OverflowException.) To explicitly define the style elements together with the culture-specific formatting information that can be present in s, use the ulong.Parse(string, System.Globalization.NumberStyles, IFormatProvider) method.

The provider parameter is an IFormatProvider implementation whose IFormatProvider.GetFormat(Type) method returns a System.Globalization.NumberFormatInfo object that provides culture-specific information about the format of s. There are three ways to use the provider parameter to supply custom formatting information to the parse operation:

• You can pass the actual System.Globalization.NumberFormatInfo object that provides formatting information. (Its implementation of IFormatProvider.GetFormat(Type) simply returns itself.)

• You can pass a System.Globalization.CultureInfo object that specifies the culture whose formatting is to be used. Its System.Globalization.CultureInfo.NumberFormat property provides formatting information.

• You can pass a custom IFormatProvider implementation. Its IFormatProvider.GetFormat(Type) method must instantiate and return the System.Globalization.NumberFormatInfo object that provides formatting information.

If provider is null, the System.Globalization.NumberFormatInfo for the current culture is used.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0