Artikel
11/18/2011

UnicodeEncoding Constructor (Boolean, Boolean)

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Initializes a new instance of the UnicodeEncoding class. Parameters specify whether to use the big-endian byte order and whether to provide a Unicode byte order mark.

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

Syntax

'Declaration
Public Sub New ( _
    bigEndian As Boolean, _
    byteOrderMark As Boolean _
)

public UnicodeEncoding(
    bool bigEndian,
    bool byteOrderMark
)

Parameters

bigEndian
Type: System.Boolean
true to use the big-endian byte order (most significant byte first), or false to use the little-endian byte order (least significant byte first).

byteOrderMark
Type: System.Boolean
true to specify that a Unicode byte order mark is provided; otherwise, false.

Remarks

It is generally more efficient to encode Unicode characters using the native byte order. For example, it is better to use the little-endian byte order on little-endian platforms, such as Intel computers, and the big-endian byte order on big-endian platforms.

This constructor creates an instance that does not throw an exception when an invalid encoding is detected.

Note:
For security reasons, your applications are recommended to enable error detection by using the constructor that accepts a throwOnInvalidBytes parameter and setting that parameter to true.

Examples

The following code example demonstrates how to create a new UnicodeEncoding instance specifying whether to support little-endian or big-endian byte ordering and the Unicode byte order mark.

Imports System.Text

Class Example

   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)

      ' Create a UnicodeEncoding without parameters.
      Dim unicodeDefault As New UnicodeEncoding()

      ' Create a UnicodeEncoding to support little-endian byte ordering
      ' and include the Unicode byte order mark.        
      Dim unicodeLittleEndianBOM As New UnicodeEncoding(False, True)
      ' Compare this UnicodeEncoding to the UnicodeEncoding without parameters.
      DescribeEquivalence(outputBlock, unicodeDefault.Equals(unicodeLittleEndianBOM))

      ' Create a UnicodeEncoding to support little-endian byte ordering
      ' and not include the Unicode byte order mark.
      Dim unicodeLittleEndianNoBOM As New UnicodeEncoding(False, False)
      ' Compare this UnicodeEncoding to the UnicodeEncoding without parameters.
      DescribeEquivalence(outputBlock, unicodeDefault.Equals(unicodeLittleEndianNoBOM))

      ' Create a UnicodeEncoding to support big-endian byte ordering
      ' and include the Unicode byte order mark.
      Dim unicodeBigEndianBOM As New UnicodeEncoding(True, True)
      ' Compare this UnicodeEncoding to the UnicodeEncoding without parameters.
      DescribeEquivalence(outputBlock, unicodeDefault.Equals(unicodeBigEndianBOM))

      ' Create a UnicodeEncoding to support big-endian byte ordering
      ' and not include the Unicode byte order mark.
      Dim unicodeBigEndianNoBOM As New UnicodeEncoding(True, False)
      ' Compare this UnicodeEncoding to the UnicodeEncoding without parameters.
      DescribeEquivalence(outputBlock, unicodeDefault.Equals(unicodeBigEndianNoBOM))
   End Sub


   Public Shared Sub DescribeEquivalence(ByVal outputBlock As System.Windows.Controls.TextBlock, ByVal isEquivalent As Boolean)
      Dim phrase As String
      If isEquivalent Then
         phrase = "An"
      Else
         phrase = "Not an"
      End If
      outputBlock.Text += String.Format("{0} equivalent encoding.", phrase) & vbCrLf
   End Sub
End Class

using System;
using System.Text;

class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {

      // Create a UnicodeEncoding without parameters.
      UnicodeEncoding unicode = new UnicodeEncoding();

      // Create a UnicodeEncoding to support little-endian byte ordering
      // and include the Unicode byte order mark.
      UnicodeEncoding unicodeLittleEndianBOM =
          new UnicodeEncoding(false, true);
      // Compare this UnicodeEncoding to the UnicodeEncoding without parameters.
      DescribeEquivalence(outputBlock, unicode.Equals(unicodeLittleEndianBOM));

      // Create a UnicodeEncoding to support little-endian byte ordering
      // and not include the Unicode byte order mark.
      UnicodeEncoding unicodeLittleEndianNoBOM =
          new UnicodeEncoding(false, false);
      // Compare this UnicodeEncoding to the UnicodeEncoding without parameters.
      DescribeEquivalence(outputBlock, unicode.Equals(unicodeLittleEndianNoBOM));

      // Create a UnicodeEncoding to support big-endian byte ordering
      // and include the Unicode byte order mark.
      UnicodeEncoding unicodeBigEndianBOM =
          new UnicodeEncoding(true, true);
      // Compare this UnicodeEncoding to the UnicodeEncoding without parameters.
      DescribeEquivalence(outputBlock, unicode.Equals(unicodeBigEndianBOM));

      // Create a UnicodeEncoding to support big-endian byte ordering
      // and not include the Unicode byte order mark.
      UnicodeEncoding unicodeBigEndianNoBOM =
          new UnicodeEncoding(true, false);
      // Compare this UnicodeEncoding to the UnicodeEncoding without parameters.
      DescribeEquivalence(outputBlock, unicode.Equals(unicodeBigEndianNoBOM));
   }

   public static void DescribeEquivalence(System.Windows.Controls.TextBlock outputBlock, Boolean isEquivalent)
   {
      outputBlock.Text += String.Format(
          "{0} equivalent encoding.", (isEquivalent ? "An" : "Not an")
      ) + "\n";
   }
}

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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