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Double.ToString Method (IFormatProvider)

Converts the numeric value of this instance to its equivalent string representation using the specified culture-specific format information.

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

public string ToString (
	IFormatProvider provider
)
public final String ToString (
	IFormatProvider provider
)
public final function ToString (
	provider : IFormatProvider
) : String

Parameters

provider

An IFormatProvider that supplies culture-specific formatting information.

Return Value

The string representation of the value of this instance as specified by provider.

The return value can be PositiveInfinitySymbol, NegativeInfinitySymbol, NaNSymbol, or a string of the form:

[sign]integral-digits[.[fractional-digits]][e[sign]exponential-digits]

Optional items are framed in square brackets ([ and ]). Items containing the term "digits" consist of a series of numeric characters ranging from 0 to 9.

sign

A negative sign or positive sign symbol.

integral-digits

A series of digits specifying the integral part of the number. Integral-digits can be absent if there are fractional-digits.

'.'

A culture-specific decimal point symbol.

fractional-digits

A series of digits specifying the fractional part of the number.

'e'

A lowercase character 'e', indicating exponential (scientific) notation.

exponential-digits

A series of digits specifying an exponent.

Some examples of the return value are "100", "-123,456,789", "123.45e+6", "500", "3.1416", "600", "-0.123", and "-Infinity".

This instance is formatted with the general format specifier ("G").

The provider parameter is an IFormatProvider instance that obtains a NumberFormatInfo object that supplies culture-specific format information. If provider is a null reference (Nothing in Visual Basic), the return value is formatted with NumberFormatInfo data for the current culture.

The following code example illustrates the use of ToString, taking a String and an IFormatProvider as parameters:

public class Temperature : IFormattable {
    /// <summary>
    /// IFormattable.ToString implementation.
    /// </summary>
    public string ToString(string format, IFormatProvider provider) {
        if( format != null ) {
            if( format.Equals("F") ) {
                return String.Format("{0}'F", this.Value.ToString());
            }
            if( format.Equals("C") ) {
                return String.Format("{0}'C", this.Celsius.ToString());
            }
        }

        return m_value.ToString(format, provider);
    }

    // The value holder
    protected double m_value;

    public double Value {
        get {
            return m_value;
        }
        set {
            m_value = value;
        }
    }

    public double Celsius {
        get {
            return (m_value-32.0)/1.8;
        }
        set {
            m_value = 1.8*value+32.0;
        }
    }
}

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

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

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0
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