UnicodeEncoding.GetCharCount Method (Byte(), Int32, Int32)
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Calculates the number of characters produced by decoding a sequence of bytes from the specified byte array.
Assembly: mscorlib (in mscorlib.dll)
'Declaration 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.Int32The number of characters produced by decoding the specified sequence of bytes.
| Exception | Condition |
|---|---|
| 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. |
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