Encoding::GetEncoding Method (Int32, EncoderFallback, DecoderFallback)
Returns the encoding associated with the specified code page identifier. Parameters specify an error handler for characters that cannot be encoded and byte sequences that cannot be decoded.
Assembly: mscorlib (in mscorlib.dll)
public: static Encoding^ GetEncoding( int codepage, EncoderFallback^ encoderFallback, DecoderFallback^ decoderFallback )
Parameters
- codepage
- Type: System::Int32
The code page identifier of the preferred encoding.
-or-
0, to use the default encoding.
- encoderFallback
- Type: System.Text::EncoderFallback
A EncoderFallback object that provides an error handling procedure when a character cannot be encoded with the current encoding.
- decoderFallback
- Type: System.Text::DecoderFallback
A DecoderFallback object that provides an error handling procedure when a byte sequence cannot be decoded with the current encoding.
| Exception | Condition |
|---|---|
| ArgumentOutOfRangeException | codepage is less than zero or greater than 65535. |
| ArgumentException | codepage is not supported by the underlying platform. |
| NotSupportedException | codepage is not supported by the underlying platform. |
Note: |
|---|
Some unsupported code pages cause ArgumentException, while others cause NotSupportedException. Therefore, your code must catch all exceptions indicated in the Exceptions section. |
The GetEncoding method relies on the underlying platform to support most code pages. However, the .NET Framework natively supports some encodings.
Note: |
|---|
The ANSI code pages can be different on different computers, or can be changed for a single computer, leading to data corruption. For the most consistent results, applications should use Unicode, such as UTF-8 (code page 65001) or UTF-16, instead of a specific code page. |
For a list of code pages, see the Encoding class topic. The application uses the GetEncodings method to get a list of all encodings.
To get the encoding associated with the default ANSI code page in the operating system's regional and language settings, the application can use a setting of 0 for the codepage parameter or the Default property. To determine the default code pages used on the system, the application uses the Windows API function GetSystemDefaultLangID. To determine the current ANSI code page, the application uses the Windows API function GetACP.
GetEncoding returns a cached instance with default settings. The application should use the constructors of derived classes to get an instance with different settings. For example, the UTF32Encoding class provides a constructor that allows enabling of error detection.
The following example demonstrates the Encoding::GetEncoding(String, EncoderFallback, DecoderFallback) method.
// This example demonstrates the EncoderReplacementFallback class. using namespace System; using namespace System::Text; int main() { // Create an encoding, which is equivalent to calling the // ASCIIEncoding class constructor. // The EncoderReplacementFallback parameter specifies that the // string, "(unknown)", replace characters that cannot be encoded. // A decoder replacement fallback is also specified, but in this // code example the decoding operation cannot fail. Encoding^ ascii = Encoding::GetEncoding("us-ascii", gcnew EncoderReplacementFallback("(unknown)"), gcnew DecoderReplacementFallback("(error)")); // The input string consists of the Unicode characters LEFT POINTING // DOUBLE ANGLE QUOTATION MARK (U+00AB), 'X' (U+0058), and RIGHT // POINTING DOUBLE ANGLE QUOTATION MARK (U+00BB). // The encoding can only encode characters in the US-ASCII range of // U+0000 through U+007F. Consequently, the characters bracketing the // 'X' character are replaced with the fallback replacement string, // "(unknown)". String^ inputString = "\u00abX\u00bb"; String^ decodedString; String^ twoNewLines = Environment::NewLine + Environment::NewLine; array <Byte>^ encodedBytes = gcnew array<Byte>(ascii->GetByteCount(inputString)); int numberOfEncodedBytes = 0; // --------------------------------------------------------------------- Console::Clear(); // Display the name of the encoding. Console::WriteLine("The name of the encoding is \"{0}\".{1}", ascii->WebName, Environment::NewLine); // Display the input string in text. Console::WriteLine("Input string ({0} characters): \"{1}\"", inputString->Length, inputString); // Display the input string in hexadecimal. Console::Write("Input string in hexadecimal: "); for each (char c in inputString) { Console::Write("0x{0:X2} ", c); } Console::Write(twoNewLines); // --------------------------------------------------------------------- // Encode the input string. Console::WriteLine("Encode the input string..."); numberOfEncodedBytes = ascii->GetBytes(inputString, 0, inputString->Length, encodedBytes, 0); // Display the encoded bytes. Console::WriteLine("Encoded bytes in hexadecimal ({0} bytes):{1}", numberOfEncodedBytes, Environment::NewLine); for(int i = 0; i < encodedBytes->Length; i++) { Console::Write("0x{0:X2} ", encodedBytes[i]); if(((i + 1) % 6) == 0) { Console::WriteLine(); } } Console::Write(twoNewLines); // --------------------------------------------------------------------- // Decode the encoded bytes, yielding a reconstituted string. Console::WriteLine("Decode the encoded bytes..."); decodedString = ascii->GetString(encodedBytes); // Display the input string and the decoded string for comparison. Console::WriteLine("Input string: \"{0}\"", inputString); Console::WriteLine("Decoded string:\"{0}\"", decodedString); } /* This code example produces the following results: The name of the encoding is "us-ascii". Input string (3 characters): "X" Input string in hexadecimal: 0xAB 0x58 0xBB Encode the input string... Encoded bytes in hexadecimal (19 bytes): 0x28 0x75 0x6E 0x6B 0x6E 0x6F 0x77 0x6E 0x29 0x58 0x28 0x75 0x6E 0x6B 0x6E 0x6F 0x77 0x6E 0x29 Decode the encoded bytes... Input string: "X" Decoded string:"(unknown)X(unknown)" */
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Note: