UTF8Encoding::GetBytes Method (array<Char>^, Int32, Int32, array<Byte>^, Int32)
Encodes a set of characters from the specified character array into the specified byte array.
Assembly: mscorlib (in mscorlib.dll)
public: virtual int GetBytes( array<wchar_t>^ chars, int charIndex, int charCount, array<unsigned char>^ bytes, int byteIndex ) override
Parameters
- chars
-
Type:
array<System::Char>^
The character array containing the set of characters to encode.
- charIndex
-
Type:
System::Int32
The index of the first character to encode.
- charCount
-
Type:
System::Int32
The number of characters to encode.
- bytes
-
Type:
array<System::Byte>^
The byte array to contain the resulting sequence of bytes.
- byteIndex
-
Type:
System::Int32
The 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 | Error detection is enabled, and chars contains an invalid sequence of characters. -or- bytes does not have enough capacity from byteIndex to the end of the array to accommodate the resulting bytes. |
| EncoderFallbackException | A fallback occurred (see Character Encoding in the .NET Framework for complete explanation) -and- EncoderFallback is set to EncoderExceptionFallback. |
To calculate the exact array size required by GetBytes to store the resulting bytes, you call the GetByteCount method. To calculate the maximum array size, you 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 an ArgumentException exception. Without error detection, invalid sequences are ignored, and no exception is thrown.
Data to be converted, such as data read from a stream, might be available only in sequential blocks. In this case, or if the amount of data is so large that it needs to be divided into smaller blocks, use the Decoder or the Encoder provided by the GetDecoder method or the GetEncoder method, respectively.
To ensure that the encoded bytes are decoded properly when they are saved as a file or as a stream, you can prefix a stream of encoded bytes with a preamble. Inserting the preamble at the beginning of a byte stream (such as at the beginning of a series of bytes to be written to a file) is the developer's responsibility. The GetBytes method does not prepend a preamble to the beginning of a sequence of encoded bytes.
The following example uses the GetBytes method to encode a range of characters from a string and stores the encoded bytes in a range of elements in a byte array.
using namespace System; using namespace System::Text; using namespace System::Collections; int main() { array<Byte>^bytes; String^ chars = "UTF8 Encoding Example"; UTF8Encoding^ utf8 = gcnew UTF8Encoding; int byteCount = utf8->GetByteCount( chars->ToCharArray(), 0, 13 ); bytes = gcnew array<Byte>(byteCount); int bytesEncodedCount = utf8->GetBytes( chars, 0, 13, bytes, 0 ); Console::WriteLine( "{0} bytes used to encode string.", bytesEncodedCount ); Console::Write( "Encoded bytes: " ); IEnumerator^ myEnum = bytes->GetEnumerator(); while ( myEnum->MoveNext() ) { Byte b = safe_cast<Byte>(myEnum->Current); Console::Write( "[{0}]", b ); } Console::WriteLine(); }
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1