GetByteCount Method (String)
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UnicodeEncoding.GetByteCount Method (String)

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Calculates the number of bytes produced by encoding the characters in the specified string.

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

public override int GetByteCount(
	string s


Type: System.String
The string that contains the set of characters to encode.

Return Value

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


s is null (Nothing).


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


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


A fallback occurred.

To calculate the exact array size required by GetBytes to store the resulting bytes, call the GetByteCount method. To calculate the maximum array size, call the GetMaxByteCount method. The GetByteCount method generally allocates less memory, while the GetMaxByteCount 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.


To ensure that the encoded bytes are decoded properly, the application should prefix encoded bytes with a preamble.

The following code example demonstrates how to use the GetByteCount method to return the number of bytes required to encode a String using UnicodeEncoding.

using System;
using System.Text;

class Example
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
      String chars = "Unicode Encoding Example";

      UnicodeEncoding Unicode = new UnicodeEncoding();
      int byteCount = Unicode.GetByteCount(chars);
      outputBlock.Text += String.Format(
          "{0} bytes needed to encode string.", byteCount
      ) + "\n";

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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