/// <summary>
/// Fixes file size field, max records field and number of objects field.
/// </summary>
public void FixHeader()
{
if (!stream.CanSeek)
{
throw new WmfException("Cannot fix WMF header since the stream does not support seeking!");
}
//Skip WmfFormat record
stream.Seek(22, SeekOrigin.Begin);
//Read whole WmfHeader record
byte[] buffer = new byte[18];
stream.Read(buffer, 0, 18);
//Create new header record
var header = new WmfHeader();
using (var ms = new MemoryStream(buffer))
{
using (var reader = new BinaryReader(ms))
{
uint max, count;
Find(out max, out count);
long l = stream.Length - 22; //Length without WmfFormat in bytes
if (l % 2 == 1)
{
l += 1; //Round to WORD padding
}
long size = l / 2; //Length in words
header.Read(reader);
header.FileSize = (uint)size;
header.NumberOfObjects = (ushort)count;
header.MaxRecord = max;
}
}
byte[] fix = new byte[18];
using (var ms = new MemoryStream())
{
using (var writer = new BinaryWriter(ms))
{
header.Write(writer);
fix = ms.ToArray();
}
}
//Rewind back to position of overwrite
this.stream.Seek(22, SeekOrigin.Begin);
this.writer.Write(fix);
//Forward to when fixing started
stream.Seek(0, SeekOrigin.End);
}
public IBinaryRecord Read()
{
if (!this.IsFormatRead)
{
this.IsFormatRead = true;
var format = new WmfFormat();
format.Read(reader);
return(format);
}
if (!this.IsHeaderRead)
{
this.IsHeaderRead = true;
var header = new WmfHeader();
header.Read(reader);
return(header);
}
long begin = reader.BaseStream.Position;
uint length = reader.ReadUInt32(); //Length in WORDs
ushort type = reader.ReadUInt16();
var rt = (RecordType)type;
var record = WmfHelper.GetRecordByType(rt) as WmfBinaryRecord;
if (record == null)
{
record = new WmfUnknownRecord();
record.RecordType = rt; //Only set for UnknownRecord otherwise it is already defined by attribute above the class
}
record.RecordSize = length;
record.Read(reader);
long end = reader.BaseStream.Position;
long rlen = end - begin; //Read length
long excess = 2 * length - rlen;
if (excess > 0)
{
//Oops, reader did not read whole record?!
reader.Skip((int)excess);
}
return(record);
}