Parse(System.String,System.Globalization.NumberStyles,System.IFormatProvider)

Converts the string representation of a number in a specified style and culture-specific format to its 16-bit unsigned integer equivalent.

Syntax

[System.CLSCompliant(false)]
public static ushort Parse (string s, System.Globalization.NumberStyles style, IFormatProvider provider)

Parameters

s
A string that represents the number to convert. The string is interpreted by using the style specified by the style parameter.
style
A bitwise combination of enumeration values that indicate the style elements that can be present in s. A typical value to specify is System.Globalization.NumberStyles.Integer.
provider
An object that supplies culture-specific formatting information about s.
s
A string that represents the number to convert. The string is interpreted by using the style specified by the style parameter.
style
A bitwise combination of enumeration values that indicate the style elements that can be present in s. A typical value to specify is System.Globalization.NumberStyles.Integer.
provider
An object that supplies culture-specific formatting information about s.

Returns

A 16-bit unsigned integer equivalent to the number specified in s.

Exceptions

Type Reason
ArgumentNullException s is a null reference.
FormatException s is not in the correct style.
OverflowException s represents a number greater than ushort.MaxValue or less than ushort.MinValue.

Type	Reason
ArgumentNullException	s is a null reference.
FormatException	s is not in the correct style.
OverflowException	s represents a number greater than ushort.MaxValue or less than ushort.MinValue.

Remarks

The style parameter defines the style elements (such as white space or the positive or negative sign symbol) that are allowed in the s parameter for the parse operation to succeed. It must be a combination of bit flags from the System.Globalization.NumberStyles enumeration.

Depending on the value of style, the s parameter may include the following elements:

[ws][$][sign]digits[.fractional_digits][E[sign]exponential_digits][ws]

Elements in square brackets ([ and ]) are optional. If style includes System.Globalization.NumberStyles.AllowHexSpecifier, the s parameter may include the following elements:

[ws]hexdigits[ws]

The following table describes each element.


ws	Optional white space. White space can appear at the beginning of s if style includes the System.Globalization.NumberStyles.AllowLeadingWhite flag, and it can appear at the end of s if style includes the System.Globalization.NumberStyles.AllowTrailingWhite flag.
$	A culture-specific currency symbol. Its position in the string is defined by the System.Globalization.NumberFormatInfo.CurrencyPositivePattern property of the System.Globalization.NumberFormatInfo object that is returned by the IFormatProvider.GetFormat(Type) method of the provider parameter. The currency symbol can appear in s if style includes the System.Globalization.NumberStyles.AllowCurrencySymbol flag.
sign	An optional sign. (The method throws an OverflowException if s includes a negative sign and represents a non-zero number.) The sign can appear at the beginning of s if style includes the System.Globalization.NumberStyles.AllowLeadingSign flag, and it can appear the end of s if style includes the System.Globalization.NumberStyles.AllowTrailingSign flag. Parentheses can be used in s to indicate a negative value if style includes the System.Globalization.NumberStyles.AllowParentheses flag.
digits	A sequence of digits from 0 through 9.
.	A culture-specific decimal point symbol. The current culture's decimal point symbol can appear in s if style includes the System.Globalization.NumberStyles.AllowDecimalPoint flag.
fractional_digits	One or more occurrences of the digit 0-9 if style includes the System.Globalization.NumberStyles.AllowExponent flag, or one or more occurrences of the digit 0 if it does not. Fractional digits can appear in s only if style includes the System.Globalization.NumberStyles.AllowDecimalPoint flag.
E	The "e" or "E" character, which indicates that the value is represented in exponential (scientific) notation. The s parameter can represent a number in exponential notation if style includes the System.Globalization.NumberStyles.AllowExponent flag.
exponential_digits	A sequence of digits from 0 through 9. The s parameter can represent a number in exponential notation if style includes the System.Globalization.NumberStyles.AllowExponent flag.
hexdigits	A sequence of hexadecimal digits from 0 through f, or 0 through F.

A string with decimal digits only (which corresponds to the System.Globalization.NumberStyles.None style) always parses successfully. Most of the remaining System.Globalization.NumberStyles members control elements that may be present, but are not required to be present, in this input string. The following table indicates how individual System.Globalization.NumberStyles members affect the elements that may be present in s.


System.Globalization.NumberStyles.None	Decimal digits only.
System.Globalization.NumberStyles.AllowDecimalPoint	The decimal point (.) and fractional_digits elements. However, if style does not include the System.Globalization.NumberStyles.AllowExponent flag, fractional_digits must consist of only one or more 0 digits; otherwise, an OverflowException is thrown.
System.Globalization.NumberStyles.AllowExponent	The "e" or "E" character, which indicates exponential notation, along with exponential_digits.
System.Globalization.NumberStyles.AllowLeadingWhite	The ws element at the beginning of s.
System.Globalization.NumberStyles.AllowTrailingWhite	The ws element at the end of s.
System.Globalization.NumberStyles.AllowLeadingSign	A sign before digits.
System.Globalization.NumberStyles.AllowTrailingSign	A sign after digits.
System.Globalization.NumberStyles.AllowParentheses	Parentheses before and after digits to indicate a negative value.
System.Globalization.NumberStyles.AllowThousands	The group separator (,) element.
System.Globalization.NumberStyles.AllowCurrencySymbol	The currency ($) element.

If the System.Globalization.NumberStyles.AllowHexSpecifier flag is used, s must be a hexadecimal value. The only other flags that can be combined with it are System.Globalization.NumberStyles.AllowLeadingWhite and System.Globalization.NumberStyles.AllowTrailingWhite. (The System.Globalization.NumberStyles enumeration includes a composite number style, System.Globalization.NumberStyles.HexNumber, that includes both white-space flags.)

Note:

If the s parameter is the string representation of a hexadecimal number, it cannot be preceded by any decoration (such as 0x or &h) that differentiates it as a hexadecimal number. This causes the parse operation to throw an exception.

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 object for the current culture is used.

Requirements

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