public override MemoryStream ExtractStream(string pathToFile)
{
try
{
var thumbnailBytes = OleDataReader.GetRawBytes(pathToFile, RevitFileMap.OleStreams.IMAGE_STREAM);
return(ExtractStream(thumbnailBytes));
}
catch (Exception ex)
{
throw new InvalidDataException($"Failed to extract the thumbnail of the following Revit file \"{pathToFile}\"", ex);
}
}
public override MemoryStream ExtractStream(MemoryStream memoryStream)
{
try
{
var thumbnailBytes = OleDataReader.GetRawBytes(memoryStream, RevitFileMap.OleStreams.IMAGE_STREAM);
return(ExtractStream(thumbnailBytes));
}
catch (Exception ex)
{
throw new InvalidDataException($"Failed to extract the thumbnail of the Revit file", ex);
}
}
/// <summary>
/// Gets the properties.
/// </summary>
/// <param name="filePath">The file path.</param>
/// <returns></returns>
internal static Dictionary <string, string> GetProperties(string filePath)
{
var basicInfo = OleDataReader.GetRawBytes(filePath, "BasicFileInfo");
var fileProps = new Dictionary <string, string>();
var supportedEncodeings = new[]
{
Encoding.Unicode,
Encoding.BigEndianUnicode,
Encoding.UTF8,
Encoding.ASCII,
Encoding.Default,
};
foreach (var encoding in supportedEncodeings)
{
var basicInfoString = encoding.GetString(basicInfo)?.TrimEnd('\u0a0d');
using var basicInfoReader = new StringReader(basicInfoString);
// ReSharper disable once RedundantAssignment
var stringLine = basicInfoReader.ReadLine(); // skip the first line
while (!string.IsNullOrWhiteSpace(stringLine = basicInfoReader.ReadLine()))
{
var parts = stringLine.Split(new[] { ":" }, 2, StringSplitOptions.None);
if (parts.Length != 2)
{
continue;
}
fileProps.Add(parts[0].Trim(), parts[1].Trim());
}
if (fileProps.Any())
{
break;
}
}
return(fileProps);
}
/// <summary>
/// Extracts the stream.
/// </summary>
/// <param name="pathToFile">The path to file.</param>
/// <returns></returns>
/// <exception cref="InvalidDataException"></exception>
public override MemoryStream ExtractStream(string pathToFile)
{
try
{
var thumbnailBytes = OleDataReader.GetRawBytes(pathToFile, RevitFileMap.OleStorage.IMAGE_STREAM);
// Validate preview data or go out
if ((thumbnailBytes == null) || (thumbnailBytes.Length <= 0))
{
return(null);
}
// read past the Revit meta-data to the start of the PNG image
var startingOffset = GetPngOffset(thumbnailBytes);
if (startingOffset == 0)
{
return(null);
}
var previewUpperBound = thumbnailBytes.GetUpperBound(0);
var pngDataBuffer = new byte[previewUpperBound - startingOffset + 1];
using (var ms = new MemoryStream(thumbnailBytes))
{
ms.Position = startingOffset;
ms.Read(pngDataBuffer, 0, pngDataBuffer.Length);
// read the PNG image data into a byte array
var outms = new MemoryStream(pngDataBuffer);
return(outms);
}
}
catch (Exception ex)
{
throw new InvalidDataException($"Failed to extract the thumbnail of the following Revit file \"{pathToFile}\"", ex);
}
}
