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NumberStyles Enumeration

Determines the styles permitted in numeric string arguments that are passed to the Parse and TryParse methods of the integral and floating-point numeric types.

This enumeration has a FlagsAttribute attribute that allows a bitwise combination of its member values.

Namespace:  System.Globalization
Assembly:  mscorlib (in mscorlib.dll)

[SerializableAttribute]
[FlagsAttribute]
[ComVisibleAttribute(true)]
public enum NumberStyles

Member nameDescription
Supported by the XNA FrameworkSupported by Portable Class LibraryNoneIndicates 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.
Supported by the XNA FrameworkSupported by Portable Class LibraryAllowLeadingWhiteIndicates that leading white-space characters can be present in the parsed string. Valid white-space characters have the Unicode values U+0009, U+000A, U+000B, U+000C, U+000D, and U+0020. Note that this is a subset of the characters for which the Char.IsWhiteSpace method returns true.
Supported by the XNA FrameworkSupported by Portable Class LibraryAllowTrailingWhiteIndicates that trailing white-space characters can be present in the parsed string. Valid white-space characters have the Unicode values U+0009, U+000A, U+000B, U+000C, U+000D, and U+0020. Note that this is a subset of the characters for which the Char.IsWhiteSpace method returns true.
Supported by the XNA FrameworkSupported by Portable Class LibraryAllowLeadingSignIndicates that the numeric string can have a leading sign. Valid leading sign characters are determined by the NumberFormatInfo.PositiveSign and NumberFormatInfo.NegativeSign properties.
Supported by the XNA FrameworkSupported by Portable Class LibraryAllowTrailingSignIndicates that the numeric string can have a trailing sign. Valid trailing sign characters are determined by the NumberFormatInfo.PositiveSign and NumberFormatInfo.NegativeSign properties.
Supported by the XNA FrameworkSupported by Portable Class LibraryAllowParenthesesIndicates that the numeric string can have one pair of parentheses enclosing the number. The parentheses indicate that the string to be parsed represents a negative number.
Supported by the XNA FrameworkSupported by Portable Class LibraryAllowDecimalPointIndicates that the numeric string can have a decimal point. If the NumberStyles value includes the AllowCurrencySymbol flag and the parsed string includes a currency symbol, the decimal separator character is determined by the NumberFormatInfo.CurrencyDecimalSeparator property. Otherwise, the decimal separator character is determined by the NumberFormatInfo.NumberDecimalSeparator property.
Supported by the XNA FrameworkSupported by Portable Class LibraryAllowThousandsIndicates that the numeric string can have group separators, such as symbols that separate hundreds from thousands. If the NumberStyles value includes the AllowCurrencySymbol flag and the string to be parsed includes a currency symbol, the valid group separator character is determined by the NumberFormatInfo.CurrencyGroupSeparator property, and the number of digits in each group is determined by the NumberFormatInfo.CurrencyGroupSizes property. Otherwise, the valid group separator character is determined by the NumberFormatInfo.NumberGroupSeparator property, and the number of digits in each group is determined by the NumberFormatInfo.NumberGroupSizes property.
Supported by the XNA FrameworkSupported by Portable Class LibraryAllowExponentIndicates that the numeric string can be in exponential notation. The AllowExponent flag allows the parsed string to contain an exponent that begins with the "E" or "e" character and that is followed by an optional positive or negative sign and an integer. In other words, it successfully parses strings in the form nnnExx, nnnE+xx, and nnnE-xx. It does not allow a decimal separator or sign in the significand or mantissa; to allow these elements in the string to be parsed, use the AllowDecimalPoint and AllowLeadingSign flags, or use a composite style that includes these individual flags.
Supported by the XNA FrameworkSupported by Portable Class LibraryAllowCurrencySymbolIndicates that the numeric string can contain a currency symbol. Valid currency symbols are determined by the NumberFormatInfo.CurrencySymbol property.
Supported by the XNA FrameworkSupported by Portable Class LibraryAllowHexSpecifierIndicates that the numeric string represents a hexadecimal value. Valid hexadecimal values include the numeric digits 0-9 and the hexadecimal digits A-F and a-f. Strings that are parsed using this style cannot be prefixed with "0x" or "&h". A string that is parsed with the AllowHexSpecifier style will always be interpreted as a hexadecimal value. The only flags that can be combined with AllowHexSpecifier are AllowLeadingWhite and AllowTrailingWhite. The NumberStyles enumeration includes a composite style, HexNumber, that consists of these three flags.
Supported by the XNA FrameworkSupported by Portable Class LibraryIntegerIndicates that the AllowLeadingWhite, AllowTrailingWhite, and AllowLeadingSign styles are used. This is a composite number style.
Supported by the XNA FrameworkSupported by Portable Class LibraryHexNumberIndicates that the AllowLeadingWhite, AllowTrailingWhite, and AllowHexSpecifier styles are used. This is a composite number style.
Supported by the XNA FrameworkSupported by Portable Class LibraryNumberIndicates that the AllowLeadingWhite, AllowTrailingWhite, AllowLeadingSign, AllowTrailingSign, AllowDecimalPoint, and AllowThousands styles are used. This is a composite number style.
Supported by the XNA FrameworkSupported by Portable Class LibraryFloatIndicates that the AllowLeadingWhite, AllowTrailingWhite, AllowLeadingSign, AllowDecimalPoint, and AllowExponent styles are used. This is a composite number style.
Supported by the XNA FrameworkSupported by Portable Class LibraryCurrencyIndicates that all styles except AllowExponent and AllowHexSpecifier are used. This is a composite number style.
Supported by the XNA FrameworkSupported by Portable Class LibraryAnyIndicates that all styles except AllowHexSpecifier are used. This is a composite number style.

The NumberStyles enumeration consists of two kinds of enumeration values that are used to parse the string representations of numeric values:

  • Individual field flags, which define specific style elements (such as white space and group separators) that can be present in the parsed string.

  • Composite number styles, which consist of multiple field flags that define the style elements that can be present in the parsed string.

Except for AllowHexSpecifier, the individual field flags in the NumberStyles enumeration define style elements that are used when parsing the string representation of a decimal number. None indicates that only digits can be present in the parsed string. The remaining individual field flags define style elements that may be, but do not have to be, present in the string representation of a decimal number for the parse operation to succeed. In contrast, the AllowHexSpecifier flag indicates that the string to be parsed is always interpreted as a hexadecimal value. The only individual field flags that can be used with AllowHexSpecifier are AllowLeadingWhite and AllowTrailingWhite. The NumberStyles enumeration includes a composite number style, HexNumber, that consists of all three flags.

The symbols (such as the currency symbol, the group separator, the decimal separator, and the positive and negative signs) that can appear in the string to be parsed are defined by the members of the System.Globalization.NumberFormatInfo object that is passed either implicitly or explicitly to the Parse method. The members table in this topic provides a description of each individual flag and indicates its relationship to NumberFormatInfo properties.

The following table lists the composite number styles and indicates which individual field flags they include. A "1" in a cell indicates that the composite number style includes the individual number style in that row. A "0" indicates that the composite number style does not include the individual number style.

Any

Currency

Float

Integer

Number

HexNumber

AllowHexSpecifier (0x0200)

0

0

0

0

0

1

AllowCurrencySymbol (0x0100)

1

1

0

0

0

0

AllowExponent (0x0080)

1

0

1

0

0

0

AllowThousands (0x0040)

1

1

0

0

1

0

AllowDecimalPoint (0x0020)

1

1

1

0

1

0

AllowParentheses (0x0010)

1

1

0

0

0

0

AllowTrailingSign (0x0008)

1

1

0

0

1

0

AllowLeadingSign (0x0004)

1

1

1

1

1

0

AllowTrailingWhite (0x0002)

1

1

1

1

1

1

AllowLeadingWhite (0x0001)

1

1

1

1

1

1

(0x1ff)

(0x17f)

(0x0a7)

(0x007)

(0x06f)

(0x203)

This example shows how to parse a string into a 32-bit integer by using various NumberStyles flags.


using System;
using System.Text;
using System.Globalization;

public sealed class App 
{
    static void Main() 
    {
        // Parse the string as a hex value and display the value as a decimal.
        String num = "A";
        int val = int.Parse(num, NumberStyles.HexNumber);
        Console.WriteLine("{0} in hex = {1} in decimal.", num, val);

        // Parse the string, allowing a leading sign, and ignoring leading and trailing white spaces.
        num = "    -45   ";
        val = int.Parse(num, NumberStyles.AllowLeadingSign | 
            NumberStyles.AllowLeadingWhite | NumberStyles.AllowTrailingWhite);
        Console.WriteLine("'{0}' parsed to an int is '{1}'.", num, val);

        // Parse the string, allowing parentheses, and ignoring leading and trailing white spaces.
        num = "    (37)   ";
        val = int.Parse(num, NumberStyles.AllowParentheses | NumberStyles.AllowLeadingSign |                         NumberStyles.AllowLeadingWhite | NumberStyles.AllowTrailingWhite);
        Console.WriteLine("'{0}' parsed to an int is '{1}'.", num, val);
    }
}

// This code produces the following output.
//
// A in hex = 10 in decimal.
// '    -45   ' parsed to an int is '-45'.
// '    (37)   ' parsed to an int is '-37'.


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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