Encoding.GetBytes Method (Char[], Int32, Int32, Byte[], Int32)
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
When overridden in a derived class, encodes a set of characters from the specified character array into the specified byte array.
Assembly: mscorlib (in mscorlib.dll)
public abstract int GetBytes( char[] chars, int charIndex, int charCount, byte[] bytes, int byteIndex )
Parameters
- chars
- Type:
System.Char
[]
The character array containing the set of characters to encode.
- charIndex
- Type: System.Int32
The zero-based index of the first character to encode.
- charCount
- Type: System.Int32
The number of characters to encode.
- bytes
- Type:
System.Byte
[]
The byte array to contain the resulting sequence of bytes.
- byteIndex
- Type: System.Int32
The zero-based index at which to start writing the resulting sequence of bytes.
| Exception | Condition |
|---|---|
| ArgumentNullException | chars is null. -or- bytes is null. |
| ArgumentOutOfRangeException | charIndex or charCount or byteIndex is less than zero. -or- charIndex and charCount do not denote a valid range in chars. -or- byteIndex is not a valid index in bytes. |
| ArgumentException | bytes does not have enough capacity from byteIndex to the end of the array to accommodate the resulting bytes. |
| EncoderFallbackException | A fallback occurred. |
To calculate the exact array size required by GetBytes to store the resulting bytes, the application should use GetByteCount. To calculate the maximum array size, the application should use GetMaxByteCount. The GetByteCount method generally allocates less memory, while the GetMaxByteCount method generally executes faster.
If the data to be converted is available only in sequential blocks (such as data read from a stream) or if the amount of data is so large that it needs to be divided into smaller blocks, the application should use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively, of a derived class.
For a discussion of programming considerations for use of this method, see the Encoding class description.
The following code example determines the number of bytes required to encode three characters from a character array, encodes the characters, and displays the resulting bytes.
using System; using System.Text; public class Example { private static System.Windows.Controls.TextBlock outputBlock; public static void Demo(System.Windows.Controls.TextBlock outBlock) { outputBlock = outBlock; // The characters to encode: // 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) // a high-surrogate value (U+D8FF) // a low-surrogate value (U+DCFF) char[] myChars = new char[] { 'z', 'a', '\u0306', '\u01FD', '\u03B2', '\uD8FF', '\uDCFF' }; // Get different encodings. Encoding u8 = Encoding.UTF8; Encoding u16LE = Encoding.Unicode; Encoding u16BE = Encoding.BigEndianUnicode; // Encode three characters starting at index 4, and print out the counts and the resulting bytes. PrintCountsAndBytes(myChars, 4, 3, u8); PrintCountsAndBytes(myChars, 4, 3, u16LE); PrintCountsAndBytes(myChars, 4, 3, u16BE); } public static void PrintCountsAndBytes(char[] chars, int index, int count, Encoding enc) { // Display the name of the encoding used. outputBlock.Text += String.Format("{0,-30} :", enc.ToString()); // Display the exact byte count. int iBC = enc.GetByteCount(chars, index, count); outputBlock.Text += String.Format(" {0,-3}", iBC); // Display the maximum byte count. int iMBC = enc.GetMaxByteCount(count); outputBlock.Text += String.Format(" {0,-3} :", iMBC); // Encode the array of chars. byte[] bytes = enc.GetBytes(chars, index, count); // The following is an alternative way to encode the array of chars: // byte[] bytes = new byte[iBC]; // enc.GetBytes( chars, index, count, bytes, bytes.GetLowerBound(0) ); // Display all the encoded bytes. PrintHexBytes(bytes); } public static void PrintHexBytes(byte[] bytes) { if ((bytes == null) || (bytes.Length == 0)) outputBlock.Text += "<none>" + "\n"; else { for (int i = 0; i < bytes.Length; i++) outputBlock.Text += String.Format("{0:X2} ", bytes[i]); outputBlock.Text += "\n"; } } } /* This example produces the following output. System.Text.UTF8Encoding : 6 12 :CE B2 F1 8F B3 BF System.Text.UnicodeEncoding : 6 8 :B2 03 FF D8 FF DC System.Text.UnicodeEncoding : 6 8 :03 B2 D8 FF DC FF */