如何使用Encoding.GetEncoding（）获取国家标准代码页？

本文介绍了如何使用Encoding.GetEncoding（）获取国家标准代码页？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！问题描述

我想编码我的字符串，然后发送到串行端口使用像这样：

I want to encode my string before send it to serial port using like this:

SerialPort port = new SerialPort(portName, baudRate, Parity.None, 8, StopBits.One); port.DtrEnable = true; Encoding encode = Encoding.GetEncoding("VISCII"); port.Encoding = encode;

使用 VISCII 是我的语言代码页。当然，在这种情况下，我得到了异常，因为它不被支持。

With VISCII is my language Code page. Of course, I get the exception in this case because it's not supported.

我如何做到这一点？任何答案将不胜感激！非常感谢这么多

How can I do this? Any answer would be appreciated! Thanks so much

推荐答案

这里有一个简单的VISCII编码/编码器/解码器： / p>

Here there is a (not-so) simple VISCII encoding/encoder/decoder:

namespace Utilities { using System; using System.Collections.ObjectModel; using System.Linq; using System.Runtime.CompilerServices; using System.Text; /// <summary> /// VISCII (en.wikipedia/wiki/Vietnamese_Standard_Code_for_Information_Interchange) /// encoding for C#. /// Fast table-based implementation not based on MappedEncoding. /// Fully thread safe/reentrant (because VISCIIEncoder is fully thread /// safe/reentrant and VISCIIDecoder is always used with flush = true). /// </summary> public class VISCIIEncodingSimple : Encoding { // Taken from en.wikipedia/wiki/Vietnamese_Standard_Code_for_Information_Interchange public static readonly ReadOnlyCollection<char> Unicodes = Array.AsReadOnly(new char[] { '\u0000', '\u0001', '\u1EB2', '\u0003', '\u0004', '\u1EB4', '\u1EAA', '\u0007', '\u0008', '\u0009', '\u000A', '\u000B', '\u000C', '\u000D', '\u000E', '\u000F', '\u0010', '\u0011', '\u0012', '\u0013', '\u1EF6', '\u0015', '\u0016', '\u0017', '\u0018', '\u1EF8', '\u001A', '\u001B', '\u001C', '\u001D', '\u1EF4', '\u001F', '\u0020', '\u0021', '\u0022', '\u0023', '\u0024', '\u0025', '\u0026', '\u0027', '\u0028', '\u0029', '\u002A', '\u002B', '\u002C', '\u002D', '\u002E', '\u002F', '\u0030', '\u0031', '\u0032', '\u0033', '\u0034', '\u0035', '\u0036', '\u0037', '\u0038', '\u0039', '\u003A', '\u003B', '\u003C', '\u003D', '\u003E', '\u003F', '\u0040', '\u0041', '\u0042', '\u0043', '\u0044', '\u0045', '\u0046', '\u0047', '\u0048', '\u0049', '\u004A', '\u004B', '\u004C', '\u004D', '\u004E', '\u004F', '\u0050', '\u0051', '\u0052', '\u0053', '\u0054', '\u0055', '\u0056', '\u0057', '\u0058', '\u0059', '\u005A', '\u005B', '\u005C', '\u005D', '\u005E', '\u005F', '\u0060', '\u0061', '\u0062', '\u0063', '\u0064', '\u0065', '\u0066', '\u0067', '\u0068', '\u0069', '\u006A', '\u006B', '\u006C', '\u006D', '\u006E', '\u006F', '\u0070', '\u0071', '\u0072', '\u0073', '\u0074', '\u0075', '\u0076', '\u0077', '\u0078', '\u0079', '\u007A', '\u007B', '\u007C', '\u007D', '\u007E', '\u007F', '\u1EA0', '\u1EAE', '\u1EB0', '\u1EB6', '\u1EA4', '\u1EA6', '\u1EA8', '\u1EAC', '\u1EBC', '\u1EB8', '\u1EBE', '\u1EC0', '\u1EC2', '\u1EC4', '\u1EC6', '\u1ED0', '\u1ED2', '\u1ED4', '\u1ED6', '\u1ED8', '\u1EE2', '\u1EDA', '\u1EDC', '\u1EDE', '\u1ECA', '\u1ECE', '\u1ECC', '\u1EC8', '\u1EE6', '\u0168', '\u1EE4', '\u1EF2', '\u00D5', '\u1EAF', '\u1EB1', '\u1EB7', '\u1EA5', '\u1EA7', '\u1EA9', '\u1EAD', '\u1EBD', '\u1EB9', '\u1EBF', '\u1EC1', '\u1EC3', '\u1EC5', '\u1EC7', '\u1ED1', '\u1ED3', '\u1ED5', '\u1ED7', '\u1EE0', '\u01A0', '\u1ED9', '\u1EDD', '\u1EDF', '\u1ECB', '\u1EF0', '\u1EE8', '\u1EEA', '\u1EEC', '\u01A1', '\u1EDB', '\u01AF', '\u00C0', '\u00C1', '\u00C2', '\u00C3', '\u1EA2', '\u0102', '\u1EB3', '\u1EB5', '\u00C8', '\u00C9', '\u00CA', '\u1EBA', '\u00CC', '\u00CD', '\u0128', '\u1EF3', '\u0110', '\u1EE9', '\u00D2', '\u00D3', '\u00D4', '\u1EA1', '\u1EF7', '\u1EEB', '\u1EED', '\u00D9', '\u00DA', '\u1EF9', '\u1EF5', '\u00DD', '\u1EE1', '\u01B0', '\u00E0', '\u00E1', '\u00E2', '\u00E3', '\u1EA3', '\u0103', '\u1EEF', '\u1EAB', '\u00E8', '\u00E9', '\u00EA', '\u1EBB', '\u00EC', '\u00ED', '\u0129', '\u1EC9', '\u0111', '\u1EF1', '\u00F2', '\u00F3', '\u00F4', '\u00F5', '\u1ECF', '\u1ECD', '\u1EE5', '\u00F9', '\u00FA', '\u0169', '\u1EE7', '\u00FD', '\u1EE3', '\u1EEE', }); private VISCIIDecoder decoder; private VISCIIEncoder encoder; /// <summary> /// This should be thread safe. The worst case is that two instances /// of VISCIIDecoder are created at the same time, but this isn't /// a problem, because VISCIIDecoder as used in this class is /// stateless. /// </summary> protected VISCIIDecoder Decoder { get { VISCIIDecoder decoder2 = decoder; // Lazy creation of Encoder if (object.ReferenceEquals(decoder2, null)) { decoder2 = decoder = new VISCIIDecoder(); } DecoderFallback decoderFallback = DecoderFallback; // If the Fallback has changed from the last call, update it if (!object.ReferenceEquals(decoderFallback, null) && !object.ReferenceEquals(decoderFallback, decoder2.Fallback)) { decoder2.Fallback = decoderFallback; } return decoder2; } } /// <summary> /// This should be thread safe. The worst case is that two instances /// of VISCIIEncoder are created at the same time, but this isn't /// a problem, because VISCIIEncoder as used in this class is /// stateless. /// </summary> protected VISCIIEncoder Encoder { get { VISCIIEncoder encoder2 = encoder; // Lazy creation of Encoder if (object.ReferenceEquals(encoder2, null)) { encoder = encoder2 = new VISCIIEncoder(); } EncoderFallback encoderFallback = EncoderFallback; // If the Fallback has changed from the last call, update it if (!object.ReferenceEquals(encoderFallback, null) && !object.ReferenceEquals(encoderFallback, encoder2.Fallback)) { encoder2.Fallback = encoderFallback; } return encoder2; } } public override string BodyName { get { return "viscii-simple"; } } public override string EncodingName { get { return BodyName; } } public override bool IsSingleByte { get { return true; } } public override object Clone() { var encoding = (VISCIIEncodingSimple)base.Clone(); // We reset the encoder and decoder of the cloned instance, // because otherwise they would be shared between the two // instances. encoding.decoder = null; encoding.encoder = null; return encoding; } public override Decoder GetDecoder() { return new VISCIIDecoder(); } public override Encoder GetEncoder() { return new VISCIIEncoder(); } public override int GetByteCount(char[] chars, int index, int count) { return Encoder.GetByteCount(chars, index, count, true); } public override int GetBytes(char[] chars, int charIndex, int charCount, byte[] bytes, int byteIndex) { return Encoder.GetBytes(chars, charIndex, charCount, bytes, byteIndex, true); } public override int GetCharCount(byte[] bytes, int index, int count) { return Decoder.GetCharCount(bytes, index, count, true); } public override int GetChars(byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex) { return Decoder.GetChars(bytes, byteIndex, byteCount, chars, charIndex, true); } public override int GetMaxByteCount(int charCount) { return charCount; } public override int GetMaxCharCount(int byteCount) { return byteCount; } } /// <summary> /// Fully thread safe/reentrant. /// </summary> public class VISCIIDecoder : Decoder { private static readonly char[] Unicodes = VISCIIEncodingSimple.Unicodes.ToArray(); public override int GetCharCount(byte[] bytes, int index, int count) { if (bytes == null) { throw new ArgumentNullException("bytes"); } if (index < 0 || index > bytes.Length) { throw new ArgumentOutOfRangeException("index"); } if (count < 0) { throw new ArgumentOutOfRangeException("count"); } if (index + count > bytes.Length) { throw new ArgumentOutOfRangeException("bytes"); } return count; } public override int GetChars(byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex) { if (bytes == null) { throw new ArgumentNullException("bytes"); } if (byteIndex < 0 || byteIndex > bytes.Length) { throw new ArgumentOutOfRangeException("byteIndex"); } if (byteCount < 0) { throw new ArgumentOutOfRangeException("byteCount"); } if (byteIndex + byteCount > bytes.Length) { throw new ArgumentOutOfRangeException("bytes"); } if (chars == null) { throw new ArgumentNullException("chars"); } if (charIndex < 0 || charIndex > chars.Length) { throw new ArgumentOutOfRangeException("charIndex"); } int byteCount2 = byteCount + byteIndex; int charIndex2 = charIndex; for (; byteIndex < byteCount2; byteIndex++) { byte b = bytes[byteIndex]; if (charIndex2 == chars.Length) { throw new ArgumentException("chars"); } // chars between 31 and 127 are equal in Unicode and VISCII chars[charIndex2] = b >= 31 && b <= 127 ? (char)b : Unicodes[b]; charIndex2++; } return charIndex2 - charIndex; } } /// <summary> /// An instance is thread safe/fully reentrant if the methods are always /// called with flush = true. /// </summary> public class VISCIIEncoder : Encoder { private static readonly byte[] VISCIIs; // Buffer for High/Low surrogates. Note that this property is read // but not written if the methods are always used with flush = true. protected char HighSurrogate { get; set; } static VISCIIEncoder() { VISCIIs = new byte[1 + VISCIIEncodingSimple.Unicodes.Max()]; for (int i = 0; i < VISCIIEncodingSimple.Unicodes.Count; i++) { VISCIIs[VISCIIEncodingSimple.Unicodes[i]] = (byte)i; } } public override int GetByteCount(char[] chars, int index, int count, bool flush) { if (chars == null) { throw new ArgumentNullException("chars"); } if (index < 0 || index > chars.Length) { throw new ArgumentOutOfRangeException("index"); } if (count < 0) { throw new ArgumentOutOfRangeException("count"); } if (index + count > chars.Length) { throw new ArgumentOutOfRangeException("chars"); } // The fallbackBuffer is created on-demand. The instance // FallbackBuffer isn't used because it wouldn't be thread safe. EncoderFallbackBuffer fallbackBuffer = null; char highSurrogate = HighSurrogate; int ret = 0; int count2 = index + count; for (; index < count2; index++) { char ch = chars[index]; if (highSurrogate != 0) { if (fallbackBuffer == null) { fallbackBuffer = (Fallback ?? EncoderFallback.ReplacementFallback).CreateFallbackBuffer(); } // If we have a High/Low surrogates couple, we pass them // together if (char.IsLowSurrogate(ch)) { if (fallbackBuffer.Fallback(highSurrogate, ch, index - 1)) { HandleFallbackCount(fallbackBuffer, ref ret); } highSurrogate = '\0'; continue; } else { // First we pass the High surrogate to the Fallback if (fallbackBuffer.Fallback(highSurrogate, index - 1)) { HandleFallbackCount(fallbackBuffer, ref ret); } highSurrogate = '\0'; // Then we fall-through normal handling } } if (ch < VISCIIs.Length && (VISCIIs[ch] != 0 || ch == '\0')) { ret++; } else { // High/low surrogate handling, done through buffer if (char.IsHighSurrogate(ch)) { highSurrogate = ch; } else { if (fallbackBuffer == null) { fallbackBuffer = (Fallback ?? EncoderFallback.ReplacementFallback).CreateFallbackBuffer(); } // Fallback if (fallbackBuffer.Fallback(ch, index)) { HandleFallbackCount(fallbackBuffer, ref ret); } } } } if (flush) { if (highSurrogate != 0) { if (fallbackBuffer == null) { fallbackBuffer = (Fallback ?? EncoderFallback.ReplacementFallback).CreateFallbackBuffer(); } if (fallbackBuffer.Fallback(highSurrogate, index - 1)) { HandleFallbackCount(fallbackBuffer, ref ret); } } } return ret; } public override int GetBytes(char[] chars, int charIndex, int charCount, byte[] bytes, int byteIndex, bool flush) { if (chars == null) { throw new ArgumentNullException("chars"); } if (charIndex < 0 || charIndex > chars.Length) { throw new ArgumentOutOfRangeException("charIndex"); } if (charCount < 0) { throw new ArgumentOutOfRangeException("charCount"); } if (charIndex + charCount > chars.Length) { throw new ArgumentOutOfRangeException("chars"); } if (bytes == null) { throw new ArgumentNullException("bytes"); } if (byteIndex < 0 || byteIndex > bytes.Length) { throw new ArgumentOutOfRangeException("byteIndex"); } // The fallbackBuffer is created on-demand. The instance // FallbackBuffer isn't used because it wouldn't be thread safe. EncoderFallbackBuffer fallbackBuffer = null; // Written only on flush = false char highSurrogate = HighSurrogate; int charCount2 = charIndex + charCount; int byteIndex2 = byteIndex; for (; charIndex < charCount2; charIndex++) { char ch = chars[charIndex]; if (highSurrogate != 0) { if (fallbackBuffer == null) { fallbackBuffer = (Fallback ?? EncoderFallback.ReplacementFallback).CreateFallbackBuffer(); } // If we have a High/Low surrogates couple, we pass them // together if (char.IsLowSurrogate(ch)) { if (fallbackBuffer.Fallback(highSurrogate, ch, charIndex - 1)) { HandleFallbackWrite(fallbackBuffer, bytes, ref byteIndex2); } highSurrogate = '\0'; continue; } else { // First we pass the High surrogate to the Fallback if (fallbackBuffer.Fallback(highSurrogate, charIndex - 1)) { HandleFallbackWrite(fallbackBuffer, bytes, ref byteIndex2); } highSurrogate = '\0'; // Then we fall-through normal handling } } byte b; if (ch < VISCIIs.Length && ((b = VISCIIs[ch]) != 0 || ch == '\0')) { // Recognized character WriteByte(bytes, byteIndex2, b); byteIndex2++; } else { // High/low surrogate handling, done through buffer if (char.IsHighSurrogate(ch)) { highSurrogate = ch; } else { if (fallbackBuffer == null) { fallbackBuffer = (Fallback ?? EncoderFallback.ReplacementFallback).CreateFallbackBuffer(); } // Fallback if (fallbackBuffer.Fallback(ch, charIndex)) { HandleFallbackWrite(fallbackBuffer, bytes, ref byteIndex2); } } } } if (flush) { if (highSurrogate != 0) { if (fallbackBuffer == null) { fallbackBuffer = (Fallback ?? EncoderFallback.ReplacementFallback).CreateFallbackBuffer(); } if (fallbackBuffer.Fallback(highSurrogate, charIndex - 1)) { HandleFallbackWrite(fallbackBuffer, bytes, ref byteIndex2); } } } else { HighSurrogate = highSurrogate; } return byteIndex2 - byteIndex; } protected static void HandleFallbackCount(EncoderFallbackBuffer fallbackBuffer, ref int count) { while (fallbackBuffer.Remaining > 0) { char ch = fallbackBuffer.GetNextChar(); if (!(ch < VISCIIs.Length && (VISCIIs[ch] != 0 || ch == '\0'))) { throw new EncoderFallbackException(); } count++; } } protected static void HandleFallbackWrite(EncoderFallbackBuffer fallbackBuffer, byte[] bytes, ref int byteIndex) { while (fallbackBuffer.Remaining > 0) { char ch = fallbackBuffer.GetNextChar(); byte b; if (!(ch < VISCIIs.Length && ((b = VISCIIs[ch]) != 0 || ch == '\0'))) { throw new EncoderFallbackException(); } WriteByte(bytes, byteIndex, b); byteIndex++; } } // Remove the next line if using .NET < 4.5 [MethodImpl(MethodImplOptions.AggressiveInlining)] protected static void WriteByte(byte[] bytes, int byteIndex, byte b) { if (byteIndex == bytes.Length) { throw new ArgumentException("bytes"); } bytes[byteIndex] = b; } } }

p>

use it like:

{ var decoder = new VISCIIEncodingSimple.VISCIIDecoder(); var encoder = new VISCIIEncodingSimple.VISCIIEncoder(); // Some characters that are part of the VISCII character set/aren't part of the VISCII character set // Illegal characters are replaced with ? string str = "OK:ABCD1234!~|OK:\x00\x01\x03\x04\x7F|OK:ẲẴẪỶỸỴẠỮ|KO:\x02\x05\x06§|KO:\U0001F602|KO:\U000100000|KO:\uD800\uD800|KO:\uDBFF\uDBFF|KO:\uD800"; char[] chars = str.ToCharArray(); var byteCount = encoder.GetByteCount(chars, 0, chars.Length, true); var bytes = new byte[byteCount]; var res = encoder.GetBytes(chars, 0, chars.Length, bytes, 0, true); int charCount = decoder.GetCharCount(bytes, 0, bytes.Length); var chars2 = new char[charCount]; var res2 = decoder.GetChars(bytes, 0, bytes.Length, chars2, 0, true); var str2 = new string(chars2); } { var encoding = new VISCIIEncodingSimple(); // Some characters that are part of the VISCII character set/aren't part of the VISCII character set // Illegal characters are replaced with ? string str = "OK:ABCD1234!~|OK:\x00\x01\x03\x04\x7F|OK:ẲẴẪỶỸỴẠỮ|KO:\x02\x05\x06§|KO:\U0001F602|KO:\U000100000|KO:\uD800\uD800|KO:\uDBFF\uDBFF|KO:\uD800"; var bytes = encoding.GetBytes(str); var str2 = encoding.GetString(bytes); }

它是基于 en.wikipedia/wiki/Vietnamese_Standard_Code_for_Information_Interchange

请注意，这是我的第一个 Encoder / 解码器子类，所以我不是100％肯定我做了一切， done： - ）

Note that this is my first Encoder/Decoder subclass, so I'm not 100% sure I did everything as it should be done :-)