/// <summary>
/// Removes the preamble information (if present) from the specified <see cref="Stream"/>, and <paramref name="source"/> is being closed and disposed.
/// </summary>
/// <param name="source">The input <see cref="Stream"/> to process.</param>
/// <param name="encoding">The encoding to use when determining the preamble to remove.</param>
/// <returns>A <see cref="Stream"/> without preamble information.</returns>
public static Stream RemovePreamble(Stream source, Encoding encoding)
{
Validator.ThrowIfNull(source, nameof(source));
byte[] bytes = ByteConverter.FromStream(source);
bytes = ByteUtility.RemovePreamble(bytes, encoding);
MemoryStream output;
MemoryStream tempOutput = null;
try
{
tempOutput = new MemoryStream(bytes);
tempOutput.Position = 0;
output = tempOutput;
tempOutput = null;
}
finally
{
if (tempOutput != null)
{
tempOutput.Dispose();
}
using (source) // because we return a stream, close the source
{
}
}
output.Position = 0;
return(output);
}
/// <summary>
/// Converts the entire XML <see cref="Stream"/> object from one encoding to another.
/// </summary>
/// <param name="source">The <see cref="Stream"/> to apply the conversion to.</param>
/// <param name="sourceEncoding">The source encoding format.</param>
/// <param name="targetEncoding">The target encoding format.</param>
/// <param name="sequence">Determines whether too keep or remove any preamble sequences.</param>
/// <param name="omitXmlDeclaration">if set to <c>true</c> omit the XML declaration; otherwise <c>false</c>. The default is false.</param>
/// <returns>A <see cref="Stream"/> object containing the results of converting bytes from sourceEncoding to targetEncoding.</returns>
public static Stream ChangeEncoding(Stream source, Encoding sourceEncoding, Encoding targetEncoding, PreambleSequence sequence, bool omitXmlDeclaration)
{
if (source == null)
{
throw new ArgumentNullException(nameof(source));
}
if (sourceEncoding == null)
{
throw new ArgumentNullException(nameof(sourceEncoding));
}
if (targetEncoding == null)
{
throw new ArgumentNullException(nameof(targetEncoding));
}
if (sourceEncoding.Equals(targetEncoding))
{
return(source);
}
long startingPosition = -1;
if (source.CanSeek)
{
startingPosition = source.Position;
source.Position = 0;
}
Stream stream;
Stream tempStream = null;
try
{
tempStream = new MemoryStream();
XmlDocument document = new XmlDocument();
document.Load(source);
if (document.FirstChild.NodeType == XmlNodeType.XmlDeclaration)
{
XmlDeclaration declaration = (XmlDeclaration)document.FirstChild;
declaration.Encoding = targetEncoding.WebName;
}
XmlWriterSettings settings = new XmlWriterSettings();
settings.Encoding = targetEncoding;
settings.Indent = true;
settings.OmitXmlDeclaration = omitXmlDeclaration;
using (XmlWriter writer = XmlWriter.Create(tempStream, settings))
{
document.Save(writer);
writer.Flush();
}
if (source.CanSeek)
{
source.Seek(startingPosition, SeekOrigin.Begin);
} // reset to original position
tempStream.Position = 0;
switch (sequence)
{
case PreambleSequence.Keep:
stream = tempStream;
tempStream = null;
break;
case PreambleSequence.Remove:
byte[] valueInBytes = ((MemoryStream)tempStream).ToArray();
using (tempStream)
{
valueInBytes = ByteUtility.RemovePreamble(valueInBytes, targetEncoding);
}
tempStream = StreamConverter.FromBytes(valueInBytes);
stream = tempStream;
tempStream = null;
break;
default:
throw new ArgumentOutOfRangeException(nameof(sequence));
}
}
finally
{
if (tempStream != null)
{
tempStream.Dispose();
}
}
return(stream);
}