GetMaxCharCount Method

UnicodeEncoding.GetMaxCharCount Method

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

Calculates the maximum number of characters produced by decoding the specified number of bytes.

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

public override int GetMaxCharCount(
	int byteCount
)

Parameters

byteCount
Type: System.Int32
The number of bytes to decode.

Return Value

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

ExceptionCondition
ArgumentOutOfRangeException

byteCount is less than zero.

-or-

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

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.

The GetMaxCharCount method returns a worst-case number. If a fallback is chosen with a potentially large string, GetMaxCharCount retrieves large values.

In most cases, this method retrieves reasonable numbers for small strings. For large strings, you might have to choose between using very large buffers and catching errors in the rare case that a more reasonable buffer is exceeded. You might also want to consider a different approach using GetCharCount or Decoder.Convert.

GetMaxCharCount has no relation to GetBytes. If your application needs a similar function to use with GetBytes, it should use GetMaxByteCount.

NoteNote:

GetMaxCharCount(N) is not necessarily the same value as N* GetMaxCharCount(1).

The following code example demonstrates how to use the GetMaxCharCount method to return the maximum number of characters produced by decoding a specified number of bytes.


using System;
using System.Text;

class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      UnicodeEncoding Unicode = new UnicodeEncoding();
      int byteCount = 8;
      int maxCharCount = Unicode.GetMaxCharCount(byteCount);
      outputBlock.Text += String.Format(
          "Maximum of {0} characters needed to decode {1} bytes.",
          maxCharCount,
          byteCount
      ) + "\n";
   }
}


Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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