我有一组markdown文件要传递给jekyll项目，需要找到它们的编码格式，即使用程序或API的带有BOM的UTF-8或没有BOM或ANSI的UTF-8。
如果我通过文件的位置，则必须列出文件，读取并作为结果产生编码。
是否有任何代码或API？
我已经尝试了有效方法中提到的用于流阅读器的sr.CurrentEncoding来找到任何文件的Encoding，但是结果随notepad ++结果的不同而不同。
还试图用https://github.com/errepi/ude（Mozilla的通用字符检测器），如建议https://social.msdn.microsoft.com/Forums/vstudio/en-US/862e3342-cc88-478f- bca2-e2de6f60d2fb / detect-encoding-of-file？forum = csharpgeneral，方法是在c＃项目中实施ude.dll，但结果不如notepad ++那样有效，文件编码显示为utf-8，但从程序，结果是带有BOM的utf-8。
但是我应该从两种方法都得到相同的结果，那么问题出在哪里呢？
检测编码始终是一项棘手的工作，但是检测BOM却非常简单。要将BOM作为字节数组获取，只需使用GetPreamble()编码对象的功能即可。这应该允许您通过前导码检测整个编码范围。
现在，至于没有前导码的情况下检测UTF-8，实际上也不是那么困难。请参见，UTF8 对于在有效序列中应具有哪些值有严格的按位规则，并且您可以以一种失败的方式初始化UTF8Encoding对象，方法是在这些序列不正确时引发异常。
因此，如果您先进行BOM表检查，然后进行严格的解码检查，最后又退回到Win-1252编码（您称为“ ANSI”），那么检测就完成了。
Byte[] bytes = File.ReadAllBytes(filename);
Encoding encoding = null;
String text = null;
// Test UTF8 with BOM. This check can easily be copied and adapted
// to detect many other encodings that use BOMs.
UTF8Encoding encUtf8Bom = new UTF8Encoding(true, true);
Boolean couldBeUtf8 = true;
Byte[] preamble = encUtf8Bom.GetPreamble();
Int32 prLen = preamble.Length;
if (bytes.Length >= prLen && preamble.SequenceEqual(bytes.Take(prLen)))
{
// UTF8 BOM found; use encUtf8Bom to decode.
try
{
// Seems that despite being an encoding with preamble,
// it doesn't actually skip said preamble when decoding...
text = encUtf8Bom.GetString(bytes, prLen, bytes.Length - prLen);
encoding = encUtf8Bom;
}
catch (ArgumentException)
{
// Confirmed as not UTF-8!
couldBeUtf8 = false;
}
}
// use boolean to skip this if it's already confirmed as incorrect UTF-8 decoding.
if (couldBeUtf8 && encoding == null)
{
// test UTF-8 on strict encoding rules. Note that on pure ASCII this will
// succeed as well, since valid ASCII is automatically valid UTF-8.
UTF8Encoding encUtf8NoBom = new UTF8Encoding(false, true);
try
{
text = encUtf8NoBom.GetString(bytes);
encoding = encUtf8NoBom;
}
catch (ArgumentException)
{
// Confirmed as not UTF-8!
}
}
// fall back to default ANSI encoding.
if (encoding == null)
{
encoding = Encoding.GetEncoding(1252);
text = encoding.GetString(bytes);
}
请注意，Windows-1252（美国/西欧ANSI）是每个字符一个字节的编码，这意味着其中的所有内容都会产生技术上有效的字符，因此，除非您采用启发式方法，否则无法对其进行进一步的检测。区别于其他每个字符一个字节的编码。
死灵术。
示例（DetectOrGuessEncoding）：
namespace SQLMerge
{
class EncodingDetector
{
public static System.Text.Encoding BomInfo(string srcFile)
{
return BomInfo(srcFile, false);
} // End Function BomInfo
public static System.Text.Encoding BomInfo(string srcFile, bool thorough)
{
byte[] b = new byte[5];
using (System.IO.FileStream file = new System.IO.FileStream(srcFile, System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read))
{
int numRead = file.Read(b, 0, 5);
if (numRead < 5)
System.Array.Resize(ref b, numRead);
file.Close();
} // End Using file
if (b.Length >= 4 && b[0] == 0x00 && b[1] == 0x00 && b[2] == 0xFE && b[3] == 0xFF) // UTF32-BE
return System.Text.Encoding.GetEncoding("utf-32BE"); // UTF-32, big-endian
else if (b.Length >= 4 && b[0] == 0xFF && b[1] == 0xFE && b[2] == 0x00 && b[3] == 0x00) // UTF32-LE
return System.Text.Encoding.UTF32; // UTF-32, little-endian
// https://en.wikipedia.org/wiki/Byte_order_mark#cite_note-14
else if (b.Length >= 4 && b[0] == 0x2b && b[1] == 0x2f && b[2] == 0x76 && (b[3] == 0x38 || b[3] == 0x39 || b[3] == 0x2B || b[3] == 0x2F)) // UTF7
return System.Text.Encoding.UTF7; // UTF-7
else if (b.Length >= 3 && b[0] == 0xEF && b[1] == 0xBB && b[2] == 0xBF) // UTF-8
return System.Text.Encoding.UTF8; // UTF-8
else if (b.Length >= 2 && b[0] == 0xFE && b[1] == 0xFF) // UTF16-BE
return System.Text.Encoding.BigEndianUnicode; // UTF-16, big-endian
else if (b.Length >= 2 && b[0] == 0xFF && b[1] == 0xFE) // UTF16-LE
return System.Text.Encoding.Unicode; // UTF-16, little-endian
// Maybe there is a future encoding ...
// PS: The above yields more than this - this doesn't find UTF7 ...
if (thorough)
{
System.Collections.Generic.List<System.Collections.Generic.KeyValuePair<System.Text.Encoding, byte[]>> lsPreambles =
new System.Collections.Generic.List<System.Collections.Generic.KeyValuePair<System.Text.Encoding, byte[]>>();
foreach (System.Text.EncodingInfo ei in System.Text.Encoding.GetEncodings())
{
System.Text.Encoding enc = ei.GetEncoding();
byte[] preamble = enc.GetPreamble();
if (preamble == null)
continue;
if (preamble.Length == 0)
continue;
if (preamble.Length > b.Length)
continue;
System.Collections.Generic.KeyValuePair<System.Text.Encoding, byte[]> kvp =
new System.Collections.Generic.KeyValuePair<System.Text.Encoding, byte[]>(enc, preamble);
lsPreambles.Add(kvp);
} // Next ei
// li.Sort((a, b) => a.CompareTo(b)); // ascending sort
// li.Sort((a, b) => b.CompareTo(a)); // descending sort
lsPreambles.Sort(
delegate (
System.Collections.Generic.KeyValuePair<System.Text.Encoding, byte[]> kvp1,
System.Collections.Generic.KeyValuePair<System.Text.Encoding, byte[]> kvp2)
{
return kvp2.Value.Length.CompareTo(kvp1.Value.Length);
}
);
for (int j = 0; j < lsPreambles.Count; ++j)
{
for (int i = 0; i < lsPreambles[j].Value.Length; ++i)
{
if (b[i] != lsPreambles[j].Value[i])
{
goto NEXT_J_AND_NOT_NEXT_I;
}
} // Next i
return lsPreambles[j].Key;
NEXT_J_AND_NOT_NEXT_I: continue;
} // Next j
} // End if (thorough)
return null;
} // End Function BomInfo
public static System.Text.Encoding DetectOrGuessEncoding(string fileName)
{
return DetectOrGuessEncoding(fileName, false);
}
public static System.Text.Encoding DetectOrGuessEncoding(string fileName, bool withOutput)
{
if (!System.IO.File.Exists(fileName))
return null;
System.ConsoleColor origBack = System.ConsoleColor.Black;
System.ConsoleColor origFore = System.ConsoleColor.White;
if (withOutput)
{
origBack = System.Console.BackgroundColor;
origFore = System.Console.ForegroundColor;
}
// System.Text.Encoding systemEncoding = System.Text.Encoding.Default; // Returns hard-coded UTF8 on .NET Core ...
System.Text.Encoding systemEncoding = GetSystemEncoding();
System.Text.Encoding enc = BomInfo(fileName);
if (enc != null)
{
if (withOutput)
{
System.Console.BackgroundColor = System.ConsoleColor.Green;
System.Console.ForegroundColor = System.ConsoleColor.White;
System.Console.WriteLine(fileName);
System.Console.WriteLine(enc);
System.Console.BackgroundColor = origBack;
System.Console.ForegroundColor = origFore;
}
return enc;
}
using (System.IO.Stream strm = System.IO.File.OpenRead(fileName))
{
UtfUnknown.DetectionResult detect = UtfUnknown.CharsetDetector.DetectFromStream(strm);
if (detect != null && detect.Details != null && detect.Details.Count > 0 && detect.Details[0].Confidence < 1)
{
if (withOutput)
{
System.Console.BackgroundColor = System.ConsoleColor.Red;
System.Console.ForegroundColor = System.ConsoleColor.White;
System.Console.WriteLine(fileName);
System.Console.WriteLine(detect);
System.Console.BackgroundColor = origBack;
System.Console.ForegroundColor = origFore;
}
foreach (UtfUnknown.DetectionDetail detail in detect.Details)
{
if (detail.Encoding == systemEncoding
|| detail.Encoding == System.Text.Encoding.UTF8
)
return detail.Encoding;
}
return detect.Details[0].Encoding;
}
else if (detect != null && detect.Details != null && detect.Details.Count > 0)
{
if (withOutput)
{
System.Console.BackgroundColor = System.ConsoleColor.Green;
System.Console.ForegroundColor = System.ConsoleColor.White;
System.Console.WriteLine(fileName);
System.Console.WriteLine(detect);
System.Console.BackgroundColor = origBack;
System.Console.ForegroundColor = origFore;
}
return detect.Details[0].Encoding;
}
enc = GetSystemEncoding();
if (withOutput)
{
System.Console.BackgroundColor = System.ConsoleColor.DarkRed;
System.Console.ForegroundColor = System.ConsoleColor.Yellow;
System.Console.WriteLine(fileName);
System.Console.Write("Assuming ");
System.Console.Write(enc.WebName);
System.Console.WriteLine("...");
System.Console.BackgroundColor = origBack;
System.Console.ForegroundColor = origFore;
}
return systemEncoding;
} // End Using strm
} // End Function DetectOrGuessEncoding
public static System.Text.Encoding GetSystemEncoding()
{
// The OEM code page for use by legacy console applications
// int oem = System.Globalization.CultureInfo.CurrentCulture.TextInfo.OEMCodePage;
// The ANSI code page for use by legacy GUI applications
// int ansi = System.Globalization.CultureInfo.InstalledUICulture.TextInfo.ANSICodePage; // Machine
int ansi = System.Globalization.CultureInfo.CurrentCulture.TextInfo.ANSICodePage; // User
try
{
// /sf/ask/2693375751/
#if ( NETSTANDARD && !NETSTANDARD1_0 ) || NETCORE || NETCOREAPP3_0 || NETCOREAPP3_1
System.Text.Encoding.RegisterProvider(System.Text.CodePagesEncodingProvider.Instance);
#endif
System.Text.Encoding enc = System.Text.Encoding.GetEncoding(ansi);
return enc;
}
catch (System.Exception)
{ }
try
{
foreach (System.Text.EncodingInfo ei in System.Text.Encoding.GetEncodings())
{
System.Text.Encoding e = ei.GetEncoding();
// 20'127: US-ASCII
if (e.WindowsCodePage == ansi && e.CodePage != 20127)
{
return e;
}
}
}
catch (System.Exception)
{ }
// return System.Text.Encoding.GetEncoding("iso-8859-1");
return System.Text.Encoding.UTF8;
} // End Function GetSystemEncoding
} // End Class
}
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