Encoding.GetCharCount Method (array<Byte[], Int32, Int32)

Parameters

• bytes
  Type: array<System.Byte[]
  The byte array containing the sequence of bytes to decode.

• index
  Type: System.Int32
  The zero-based index of the first byte to decode.

• count
  Type: System.Int32
  The number of bytes to decode.

Return Value

Type: System.Int32
The number of characters produced by decoding the specified sequence of bytes.

Imports System.Text

Class Example
   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      Dim unicodeString As String = "This string contains the unicode character Pi(" & ChrW(&H3A0) & ")"

      ' Create two different encodings.
      Dim utf8 As Encoding = Encoding.UTF8
      Dim unicode As Encoding = Encoding.Unicode

      ' Convert the string into a byte[].
      Dim unicodeBytes As Byte() = unicode.GetBytes(unicodeString)

      ' Perform the conversion from one encoding to the other.
      Dim utf8Bytes As Byte() = Encoding.Convert(unicode, utf8, unicodeBytes)

      ' Convert the new byte[] into a char[] and then into a string.
      Dim utf8Chars(utf8.GetCharCount(utf8Bytes, 0, utf8Bytes.Length) - 1) As Char
      utf8.GetChars(utf8Bytes, 0, utf8Bytes.Length, utf8Chars, 0)
      Dim utf8String As New String(utf8Chars)

      ' Display the strings created before and after the conversion.
      outputBlock.Text += String.Format("Original string: {0}", unicodeString) & vbCrLf
      outputBlock.Text += String.Format("Ascii converted string: {0}", utf8String) & vbCrLf
   End Sub
End Class
' The example displays the following output:
'    Original string: This string contains the unicode character Pi (Π)
'    Ascii converted string: This string contains the unicode character Pi (?)

using System;
using System.Text;

class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      string unicodeString = "This string contains the unicode character Pi (\u03a0)";

      // Create two different encodings.
      Encoding utf8 = Encoding.UTF8;
      Encoding unicode = Encoding.Unicode;

      // Convert the string into a byte[].
      byte[] unicodeBytes = unicode.GetBytes(unicodeString);

      // Perform the conversion from one encoding to the other.
      byte[] utf8Bytes = Encoding.Convert(unicode, utf8, unicodeBytes);

      // Convert the new byte[] into a char[] and then into a string.
      char[] utf8Chars = new char[utf8.GetCharCount(utf8Bytes, 0, utf8Bytes.Length)];
      utf8.GetChars(utf8Bytes, 0, utf8Bytes.Length, utf8Chars, 0);
      string utf8String = new string(utf8Chars);

      // Display the strings created before and after the conversion.
      outputBlock.Text += String.Format("Original string: {0}", unicodeString) + "\n";
      outputBlock.Text += String.Format("Ascii converted string: {0}", utf8String) + "\n";
   }
}
// The example displays the following output:
//    Original string: This string contains the unicode character Pi (Π)
//    Ascii converted string: This string contains the unicode character Pi (?)

Imports System.Text

Public Class Example

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

      ' Create two instances of UTF32Encoding: one with little-endian byte order and one with big-endian byte order.
      Dim u32LE As Encoding = Encoding.GetEncoding("utf-32")
      Dim u32BE As Encoding = Encoding.GetEncoding("utf-32BE")

      ' Use a string containing the following characters:
      '    Latin Small Letter Z (U+007A)
      '    Latin Small Letter A (U+0061)
      '    Combining Breve (U+0306)
      '    Latin Small Letter AE With Acute (U+01FD)
      '    Greek Small Letter Beta (U+03B2)
      Dim myStr As String = "za" & ChrW(&H306) & ChrW(&H1FD) & ChrW(&H3B2)

      ' Encode the string using the big-endian byte order.
      ' NOTE: In VB.NET, arrays contain one extra element by default.
      '       The following line creates barrBE with the exact number of elements required.
      Dim barrBE(u32BE.GetByteCount(myStr) - 1) As Byte
      u32BE.GetBytes(myStr, 0, myStr.Length, barrBE, 0)

      ' Encode the string using the little-endian byte order.
      ' NOTE: In VB.NET, arrays contain one extra element by default.
      '       The following line creates barrLE with the exact number of elements required.
      Dim barrLE(u32LE.GetByteCount(myStr) - 1) As Byte
      u32LE.GetBytes(myStr, 0, myStr.Length, barrLE, 0)

      ' Get the char counts, decode eight bytes starting at index 0,
      ' and print out the counts and the resulting bytes.
      outputBlock.Text &= "BE array with BE encoding : "
      PrintCountsAndChars(outputBlock, barrBE, 0, 8, u32BE)
      outputBlock.Text &= "LE array with LE encoding : "
      PrintCountsAndChars(outputBlock, barrLE, 0, 8, u32LE)

   End Sub 'Main


   Public Shared Sub PrintCountsAndChars(ByVal outputBlock As System.Windows.Controls.TextBlock, ByVal bytes() As Byte, ByVal index As Integer, ByVal count As Integer, ByVal enc As Encoding)

      ' Display the name of the encoding used.
      outputBlock.Text += String.Format("{0,-25} :", enc.ToString())

      ' Display the exact character count.
      Dim iCC As Integer = enc.GetCharCount(bytes, index, count)
      outputBlock.Text += String.Format(" {0,-3}", iCC)

      ' Display the maximum character count.
      Dim iMCC As Integer = enc.GetMaxCharCount(count)
      outputBlock.Text += String.Format(" {0,-3} :", iMCC)

      ' Decode the bytes.
      Dim chars As Char() = enc.GetChars(bytes, index, count)

      ' The following is an alternative way to decode the bytes:
      ' NOTE: In VB.NET, arrays contain one extra element by default.
      '       The following line creates the array with the exact number of elements required.
      ' Dim chars(iCC - 1) As Char
      ' enc.GetChars( bytes, index, count, chars, 0 )

      ' Display the characters.
      outputBlock.Text &= chars & vbCrLf

   End Sub 'PrintCountsAndChars 

End Class 'SamplesEncoding


'This code produces the following output.  The question marks take the place of characters that cannot be displayed at the console.
'
'BE array with BE encoding : System.Text.UTF32Encoding : 2   6   :za
'LE array with LE encoding : System.Text.UTF32Encoding : 2   6   :za

using System;
using System.Text;

public class Example
{

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

      // Create two instances of UTF32Encoding: one with little-endian byte order and one with big-endian byte order.
      Encoding u32LE = Encoding.GetEncoding("utf-32");
      Encoding u32BE = Encoding.GetEncoding("utf-32BE");

      // Use a string containing the following characters:
      //    Latin Small Letter Z (U+007A)
      //    Latin Small Letter A (U+0061)
      //    Combining Breve (U+0306)
      //    Latin Small Letter AE With Acute (U+01FD)
      //    Greek Small Letter Beta (U+03B2)
      String myStr = "za\u0306\u01FD\u03B2";

      // Encode the string using the big-endian byte order.
      byte[] barrBE = new byte[u32BE.GetByteCount(myStr)];
      u32BE.GetBytes(myStr, 0, myStr.Length, barrBE, 0);

      // Encode the string using the little-endian byte order.
      byte[] barrLE = new byte[u32LE.GetByteCount(myStr)];
      u32LE.GetBytes(myStr, 0, myStr.Length, barrLE, 0);

      // Get the char counts, decode eight bytes starting at index 0,
      // and print out the counts and the resulting bytes.
      outputBlock.Text += "BE array with BE encoding : ";
      PrintCountsAndChars(outputBlock, barrBE, 0, 8, u32BE);
      outputBlock.Text += "LE array with LE encoding : ";
      PrintCountsAndChars(outputBlock, barrLE, 0, 8, u32LE);

   }


   public static void PrintCountsAndChars(System.Windows.Controls.TextBlock outputBlock, byte[] bytes, int index, int count, Encoding enc)
   {

      // Display the name of the encoding used.
      outputBlock.Text += String.Format("{0,-25} :", enc.ToString());

      // Display the exact character count.
      int iCC = enc.GetCharCount(bytes, index, count);
      outputBlock.Text += String.Format(" {0,-3}", iCC);

      // Display the maximum character count.
      int iMCC = enc.GetMaxCharCount(count);
      outputBlock.Text += String.Format(" {0,-3} :", iMCC);

      // Decode the bytes and display the characters.
      char[] chars = enc.GetChars(bytes, index, count);

      // The following is an alternative way to decode the bytes:
      // char[] chars = new char[iCC];
      // enc.GetChars( bytes, index, count, chars, 0 );

      outputBlock.Text += chars + "\n";

   }

}


/* 
This code produces the following output.  The question marks take the place of characters that cannot be displayed at the console.

BE array with BE encoding : System.Text.UTF32Encoding : 2   6   :za
LE array with LE encoding : System.Text.UTF32Encoding : 2   6   :za

*/