DateTimeFormatInfo Class

The invariant culture represents a culture that is culture-insensitive. It is based on the English language, but not on any specific English-speaking country/region. Although the data of specific cultures can be dynamic and can change to reflect new cultural conventions or user preferences, the data of the invariant culture does not change. You can instantiate a DateTimeFormatInfo object that represents the formatting conventions of the invariant culture in the following ways:

• By retrieving the value of the InvariantInfo property. The returned DateTimeFormatInfo object is read-only.

• By calling the DateTimeFormatInfo constructor. The returned DateTimeFormatInfo object is read/write.

• By retrieving the value of the DateTimeFormat property from the CultureInfo object that is returned by the CultureInfo.InvariantCulture property. The returned DateTimeFormatInfo object is read-only.

The following example uses each of these methods to instantiate a DateTimeFormatInfo object that represents the invariant culture. It then indicates whether the object is read-only.

System.Globalization.DateTimeFormatInfo dtfi; 

dtfi = System.Globalization.DateTimeFormatInfo.InvariantInfo;
Console.WriteLine(dtfi.IsReadOnly);               

dtfi = new System.Globalization.DateTimeFormatInfo();
Console.WriteLine(dtfi.IsReadOnly);               

dtfi = System.Globalization.CultureInfo.InvariantCulture.DateTimeFormat;
Console.WriteLine(dtfi.IsReadOnly);                
// The example displays the following output:
//       True
//       False
//       True      

A specific culture represents a language that is spoken in a particular country/region. For example, en-US is a specific culture that represents the English language spoken in the United States, and en-CA is a specific culture that represents the English language spoken in Canada. You can instantiate a DateTimeFormatInfo object that represents the formatting conventions of a specific culture in the following ways:

• By retrieving the value of the CurrentInfo property. This returns a read-only DateTimeFormatInfo object that represents the formatting conventions of the current culture.

• By instantiating a CultureInfo object that represents a specific culture and retrieving the value of its CultureInfo.DateTimeFormat property. Whether the DateTimeFormatInfo object is read/write or read-only depends on how its associated CultureInfo object is instantiated:

  • If the object is instantiated by calling the CultureInfo.GetCultureInfo property, it is read-only.

  • If the object is instantiated by calling the CultureInfo.CultureInfo constructor or the CultureInfo.CreateSpecificCulture method, it is read/write.

The following example illustrates each of these ways to instantiate a DateTimeFormatInfo object and indicates whether the resulting object is read-only.

System.Globalization.CultureInfo ci = null;
System.Globalization.DateTimeFormatInfo dtfi = null;

// Get the current culture//s DateTimeFormatInfo object.
dtfi = System.Globalization.DateTimeFormatInfo.CurrentInfo;
Console.WriteLine("{0} from CurrentInfo property: {1}", 
                  System.Globalization.CultureInfo.CurrentCulture.Name, 
                  dtfi.IsReadOnly);

// Instantiate a culture using CreateSpecificCulture.
ci = System.Globalization.CultureInfo.CreateSpecificCulture("en-US");
dtfi = ci.DateTimeFormat;
Console.WriteLine("{0} from CreateSpecificCulture: {1}", ci.Name, dtfi.IsReadOnly);

// Instantiate a culture using the CultureInfo constructor.
ci = new System.Globalization.CultureInfo("en-CA"); 
dtfi = ci.DateTimeFormat;
Console.WriteLine("{0} from CultureInfo constructor: {1}", ci.Name, dtfi.IsReadOnly);

ci = System.Globalization.CultureInfo.GetCultureInfo("en-AU");
dtfi = ci.DateTimeFormat;
Console.WriteLine("{0} from GetCultureInfo: {1}", ci.Name, dtfi.IsReadOnly);
// The example displays the following output:
//       en-US from CurrentInfo property: True
//       en-US from CreateSpecificCulture: False
//       en-CA from CultureInfo constructor: False
//       en-AU from GetCultureInfo: True      

A neutral culture represents a culture or language that is independent of a country/region; it is typically the parent of one or more specific cultures. For example, Fr is a neutral culture for the French language and the parent of the fr-FR culture. You can instantiate a DateTimeFormatInfo object that represents the formatting conventions of a neutral culture in the following ways:

• By retrieving a CultureInfo object that represents a neutral culture from the CultureInfo.Parent property of its specific culture, and then retrieving the value of its CultureInfo.DateTimeFormat property.

  Caution
  In general, the parent of a neutral culture is the invariant culture. However, in some cases, the parent of a neutral culture is another neutral culture. For example, sr-Cyrl (or Serbian Cyrillic) is a neutral culture that represents the Serbian language using the Cyrillic character set. Its parent is another neutral culture, sr (or Serbian), which represents the Serbian language.

• By instantiating a neutral culture by calling the CultureInfo.CultureInfo class constructor, the CultureInfo.CreateSpecificCulture method, or the CultureInfo.GetCultureInfo method to instantiate a CultureInfo object that represents a neutral culture and retrieving the DateTimeFormatInfo object from its CultureInfo.DateTimeFormat property. The following example illustrates these ways of instantiating a CultureInfo object that represents a neutral culture.

  C#

  VB

  Copy

  
  System.Globalization.CultureInfo specific, neutral;
  System.Globalization.DateTimeFormatInfo dtfi;
  
  specific = System.Globalization.CultureInfo.CreateSpecificCulture("fr-FR");
  neutral = specific.Parent;
  dtfi = neutral.DateTimeFormat;
  
  neutral = new System.Globalization.CultureInfo("fr");
  dtfi = neutral.DateTimeFormat;
  
  neutral = System.Globalization.CultureInfo.CreateSpecificCulture("fr");
  dtfi = neutral.DateTimeFormat;
  
  neutral = System.Globalization.CultureInfo.GetCultureInfo("fr");
  dtfi = neutral.DateTimeFormat;
  
  dtfi = System.Globalization.CultureInfo.GetCultureInfo("fr-FR").Parent.DateTimeFormat;
  
  
  

You can instantiate a DateTimeFormatInfo object that represents the formatting conventions of the current culture in the following ways:

• By retrieving the value of the CurrentInfo property. The returned DateTimeFormatInfo object is read-only.

• By retrieving the value of the DateTimeFormat property from the CultureInfo object that is returned by the CultureInfo.CurrentCulture property. The returned DateTimeFormatInfo object is read-only.

The following example uses each of these methods to instantiate a DateTimeFormatInfo object that represents the formatting conventions of the current culture. It then indicates whether the object is read-only.

DateTimeFormatInfo dtfi;

dtfi = DateTimeFormatInfo.CurrentInfo;
Console.WriteLine(dtfi.IsReadOnly);

dtfi = CultureInfo.CurrentCulture.DateTimeFormat;
Console.WriteLine(dtfi.IsReadOnly);
// The example displays the following output:
//     True
//     True