/// <summary>
/// Rerurns up to maxEncodings codpages that are assumed to be apropriate
/// </summary>
/// <param name="input">array containing the raw data</param>
/// <param name="maxEncodings">maxiumum number of encodings to detect</param>
/// <returns>an array of Encoding with assumed encodings</returns>
public static Encoding[] DetectInputCodepages(byte[] input, int maxEncodings)
{
StopWatch.Start("DetectInputCodepages_" + Thread.CurrentThread.ManagedThreadId);
if (maxEncodings < 1)
{
throw new ArgumentOutOfRangeException("at least one encoding must be returend", "maxEncodings");
}
if (input == null)
{
throw new ArgumentNullException("input");
}
// empty strings can always be encoded as ASCII
if (input.Length == 0)
{
return new Encoding[] { Encoding.ASCII }
}
;
// expand the string to be at least 256 bytes
if (input.Length < 256)
{
byte[] newInput = new byte[256];
int steps = 256 / input.Length;
for (int i = 0; i < steps; i++)
{
Array.Copy(input, 0, newInput, input.Length * i, input.Length);
}
int rest = 256 % input.Length;
if (rest > 0)
{
Array.Copy(input, 0, newInput, steps * input.Length, rest);
}
input = newInput;
}
List <Encoding> result = new List <Encoding>();
// get the IMultiLanguage" interface
IMultiLanguage2 multilang2 = new CMultiLanguageClass();
if (multilang2 == null)
{
throw new System.Runtime.InteropServices.COMException("Failed to get IMultilang2");
}
try
{
DetectEncodingInfo[] detectedEncdings = new DetectEncodingInfo[maxEncodings];
int scores = detectedEncdings.Length;
int srcLen = input.Length;
// setup options (none)
MLDETECTCP options = MLDETECTCP.MLDETECTCP_NONE;
StopWatch.Start("multilang2.DetectInputCodepage_" + Thread.CurrentThread.ManagedThreadId);
// finally... call to DetectInputCodepage
multilang2.DetectInputCodepage(options, 0,
ref input[0], ref srcLen, ref detectedEncdings[0], ref scores);
StopWatch.Stop("multilang2.DetectInputCodepage_" + Thread.CurrentThread.ManagedThreadId);
// get result
if (scores > 0)
{
for (int i = 0; i < scores; i++)
{
// add the result
result.Add(Encoding.GetEncoding((int)detectedEncdings[i].nCodePage));
}
}
}
finally
{
Marshal.FinalReleaseComObject(multilang2);
}
StopWatch.Stop("DetectInputCodepages_" + Thread.CurrentThread.ManagedThreadId);
// nothing found
return(result.ToArray());
}
public static Encoding[] DetectOutgoingEncodings(string input, int[] preferedEncodings, bool preserveOrder)
{
if (input == null)
{
throw new ArgumentNullException("input");
}
// empty strings can always be encoded as ASCII
if (input.Length == 0)
{
return new Encoding[] { Encoding.ASCII }
}
;
List <Encoding> result = new List <Encoding>();
// get the IMultiLanguage3 interface
IMultiLanguage3 multilang3 = new CMultiLanguageClass();
if (multilang3 == null)
{
throw new System.Runtime.InteropServices.COMException("Failed to get IMultilang3");
}
try
{
int[] resultCodePages = new int[preferedEncodings.Length];
uint detectedCodepages = (uint)resultCodePages.Length;
ushort specialChar = (ushort)'?';
// get unmanaged arrays
IntPtr pPrefEncs = Marshal.AllocCoTaskMem(sizeof(uint) * preferedEncodings.Length);
IntPtr pDetectedEncs = preferedEncodings == null
? IntPtr.Zero
: Marshal.AllocCoTaskMem(sizeof(uint) * resultCodePages.Length);
try
{
if (preferedEncodings != null)
{
Marshal.Copy(preferedEncodings, 0, pPrefEncs, preferedEncodings.Length);
}
Marshal.Copy(resultCodePages, 0, pDetectedEncs, resultCodePages.Length);
MLCPF options = MLCPF.MLDETECTF_VALID_NLS |
MLCPF.MLDETECTF_PREFERRED_ONLY;
if (preserveOrder)
{
options |= MLCPF.MLDETECTF_PRESERVE_ORDER;
}
if (preferedEncodings != null)
{
options |= MLCPF.MLDETECTF_PREFERRED_ONLY;
}
// finally... call to DetectOutboundCodePage
multilang3.DetectOutboundCodePage(options,
input, (uint)input.Length,
pPrefEncs, (uint)(preferedEncodings == null ? 0 : preferedEncodings.Length),
pDetectedEncs, ref detectedCodepages,
ref specialChar);
// get result
if (detectedCodepages > 0)
{
int[] theResult = new int[detectedCodepages];
Marshal.Copy(pDetectedEncs, theResult, 0, theResult.Length);
// get the encodings for the codepages
for (int i = 0; i < detectedCodepages; i++)
{
result.Add(Encoding.GetEncoding(theResult[i]));
}
}
}
finally
{
if (pPrefEncs != IntPtr.Zero)
{
Marshal.FreeCoTaskMem(pPrefEncs);
}
Marshal.FreeCoTaskMem(pDetectedEncs);
}
}
finally
{
Marshal.FinalReleaseComObject(multilang3);
}
// nothing found
return(result.ToArray());
}
