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UnicodeEncoding.GetCharCount Method (Byte(), Int32, Int32)

Calculates the number of characters produced by decoding a sequence of bytes from the specified byte array.

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

'Declaration
<SecuritySafeCriticalAttribute> _
Public Overrides Function GetCharCount ( _
	bytes As Byte(), _
	index As Integer, _
	count As Integer _
) As Integer

Parameters

bytes
Type: 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.

ExceptionCondition
ArgumentNullException

bytes is null (Nothing).

ArgumentOutOfRangeException

index or count is less than zero.

-or-

index and count do not denote a valid range in bytes.

-or-

The resulting number of bytes is greater than the maximum number that can be returned as an integer.

ArgumentException

Error detection is enabled, and bytes contains an invalid sequence of bytes.

DecoderFallbackException

A fallback occurred (see Understanding Encodings for fuller explanation).

To calculate the exact array size required by GetChars to store the resulting characters, call the GetCharCount method. To calculate the maximum array size, call the GetMaxCharCount method. The GetCharCount method generally allocates less memory, while the GetMaxCharCount method generally executes faster.

With error detection, an invalid sequence causes this method to throw a ArgumentException. Without error detection, invalid sequences are ignored, and no exception is thrown.

The following code example demonstrates how to use the GetCharCount method to return the number of characters produced by decoding a range of elements in a byte array using UnicodeEncoding.


Imports System.Text

Class Example

   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      Dim bytes() As Byte = {85, 0, 110, 0, 105, 0, 99, 0, 111, 0, 100, 0, 101, 0}

      Dim uni As New UnicodeEncoding()
      Dim charCount As Integer = uni.GetCharCount(bytes, 2, 8)
      outputBlock.Text += String.Format("{0} characters needed to decode bytes.", charCount) & vbCrLf
   End Sub 'Main
End Class 'UnicodeEncodingExample


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

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

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