CultureInfo.ReadOnly Method (CultureInfo)


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Returns a read-only wrapper around the specified CultureInfo object.

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

Public Shared Function ReadOnly (
	ci As CultureInfo
) As CultureInfo


Type: System.Globalization.CultureInfo

The CultureInfo object to wrap.

Return Value

Type: System.Globalization.CultureInfo

A read-only CultureInfo wrapper around ci.

Exception Condition

ci is null.

This wrapper prevents any modifications to ci, or the objects returned by the ci.DateTimeFormat and ci.NumberFormat properties.

The following example shows that the ReadOnly method helps protect the DateTimeFormatInfo and NumberFormatInfo instances associated with the CultureInfo.

Imports System
Imports System.Globalization

Public Class SamplesCultureInfo

   Public Shared Sub Main()

      ' Creates a CultureInfo.
      Dim myCI As New CultureInfo("en-US")

      ' Creates a read-only CultureInfo based on myCI.
      Dim myReadOnlyCI As CultureInfo = CultureInfo.ReadOnly(myCI)

      ' Display the read-only status of each CultureInfo and their DateTimeFormat and NumberFormat properties.
      If myCI.IsReadOnly Then 
         Console.WriteLine("myCI is read only.")
         Console.WriteLine("myCI is writable.")
      End If

      If myCI.DateTimeFormat.IsReadOnly Then 
         Console.WriteLine("myCI.DateTimeFormat is read only.")
         Console.WriteLine("myCI.DateTimeFormat is writable.")
      End If

      If myCI.NumberFormat.IsReadOnly Then 
         Console.WriteLine("myCI.NumberFormat is read only.")
         Console.WriteLine("myCI.NumberFormat is writable.")
      End If

      If myReadOnlyCI.IsReadOnly Then 
         Console.WriteLine("myReadOnlyCI is read only.")
         Console.WriteLine("myReadOnlyCI is writable.")
      End If

      If myReadOnlyCI.DateTimeFormat.IsReadOnly Then 
         Console.WriteLine("myReadOnlyCI.DateTimeFormat is read only.")
         Console.WriteLine("myReadOnlyCI.DateTimeFormat is writable.")
      End If

      If myReadOnlyCI.NumberFormat.IsReadOnly Then 
         Console.WriteLine("myReadOnlyCI.NumberFormat is read only.")
         Console.WriteLine("myReadOnlyCI.NumberFormat is writable.")
      End If

   End Sub 'Main 

End Class 'SamplesCultureInfo

' This code produces the following output.
' myCI is writable.
' myCI.DateTimeFormat is writable.
' myCI.NumberFormat is writable.
' myReadOnlyCI is read only.
' myReadOnlyCI.DateTimeFormat is read only.
' myReadOnlyCI.NumberFormat is read only.

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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