Parse Méthode (String, IFormatProvider)
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Decimal.Parse, méthode (String, IFormatProvider)

 

Convertit la représentation sous forme de chaîne d'un nombre en son Decimal équivalent à l'aide des informations de format propres à la culture spécifiée.

Espace de noms:   System
Assembly:  mscorlib (dans mscorlib.dll)

public static decimal Parse(
	string s,
	IFormatProvider provider
)

Paramètres

s

Représentation sous forme de chaîne du nombre à convertir.

provider

IFormatProvider qui fournit des informations d'analyse propres à la culture concernant s.

Valeur de retour

Type: System.Decimal

Nombre Decimal équivalent au nombre figurant dans s, comme spécifié par provider.

Exception Condition
ArgumentNullException

s is null.

FormatException

s is not of the correct format

OverflowException

s represents a number less than MinValue or greater than MaxValue

This overload of the Parse(String, IFormatProvider) method is commonly used to convert text that can be formatted in a variety of ways to a Decimal 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,]digits[.fractional-digits][ws]

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

Element

Description

ws

Optional white space.

sign

An optional sign.

digits

A sequence of digits ranging from 0 to 9.

,

A culture-specific thousands separator symbol.

.

A culture-specific decimal point symbol.

fractional-digits

A sequence of digits ranging from 0 to 9.

The s parameter is interpreted using the NumberStyles.Number style.This means that white space and thousands separators are allowed but currency symbols are not.To explicitly define the elements (such as currency symbols, thousands separators, and white space) that can be present in s, use the Decimal.Parse(String, NumberStyles, IFormatProvider) method.

The provider parameter is an IFormatProvider implementation, such as a NumberFormatInfo or CultureInfo object.The provider parameter supplies culture-specific information used in parsing.If provider is null, the thread current culture is used.

A Decimal object has 29 digits of precision.If s represents a number that has more than 29 digits, but has a fractional part and is within the range of MaxValue and MinValue, the number is rounded, not truncated, to 29 digits using rounding to nearest.

If a separator is encountered in the s parameter during a parse operation, and the applicable currency or number decimal and group separators are the same, the parse operation assumes that the separator is a decimal separator rather than a group separator.For more information about separators, see CurrencyDecimalSeparator, NumberDecimalSeparator, CurrencyGroupSeparator, and NumberGroupSeparator.

The following example is the button click event handler of a Web form.It uses the array returned by the HttpRequest.UserLanguages property to determine the user's locale.It then instantiates a CultureInfo object that corresponds to that locale.The NumberFormatInfo object that belongs to that CultureInfo object is then passed to the Parse(String, IFormatProvider) method to convert the user's input to a Decimal value.

protected void OkToDecimal_Click(object sender, EventArgs e)
{
   string locale;
   decimal number;
   CultureInfo culture;

   // Return if string is empty
   if (String.IsNullOrEmpty(this.inputNumber.Text))
      return;

   // Get locale of web request to determine possible format of number
   if (Request.UserLanguages.Length == 0)
      return;
   locale = Request.UserLanguages[0];
   if (String.IsNullOrEmpty(locale))
      return;

  // Instantiate CultureInfo object for the user's locale
   culture = new CultureInfo(locale);

   // Convert user input from a string to a number
   try
   {
      number = Decimal.Parse(this.inputNumber.Text, culture.NumberFormat);
   }
   catch (FormatException)
   {
      return;
   }
   catch (Exception)
   {
      return;
   }
   // Output number to label on web form
   this.outputNumber.Text = "Number is " + number.ToString();
}

Universal Windows Platform
Disponible depuis 4.5
.NET Framework
Disponible depuis 1.1
Portable Class Library
Pris en charge dans : portable .NET platforms
Silverlight
Disponible depuis 2.0
Windows Phone Silverlight
Disponible depuis 7.0
Windows Phone
Disponible depuis 8.1
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