public bool Attach(FileStream stream, string filename, bool read_header)
{
bool ok = (stream != null);
if (ok && read_header)
{
byte[] bytes = new byte[Marshal.SizeOf(typeof(Byte))];
ok = (bytes.Length == StreamRead(stream, bytes));
if (ok)
{
Byte version = bytes[0];
int len_header;
int len_field;
switch (version)
{
case Const.MAGIC_DBASE4:
case Const.MAGIC_DBASE4_MEMO:
len_header = Marshal.SizeOf(typeof(DBF_FILEHEADER_4));
len_field = Marshal.SizeOf(typeof(DBF_FILEFIELD_4));
break;
case Const.MAGIC_DBASE3:
case Const.MAGIC_DBASE3_MEMO:
case Const.MAGIC_DBASE3_MEMO_2:
case Const.MAGIC_FOXPRO:
default:
len_header = Marshal.SizeOf(typeof(DBF_FILEHEADER_3));
len_field = Marshal.SizeOf(typeof(DBF_FILEFIELD_3));
break;
}
bytes = new byte[len_header];
StreamSeek(stream, 0);
ok = (len_header == StreamRead(stream, bytes));
if (ok)
{
switch (version)
{
case Const.MAGIC_DBASE4:
case Const.MAGIC_DBASE4_MEMO:
{
DBF_FILEHEADER_4 header = Utility.PtrToStructure <DBF_FILEHEADER_4>(bytes);
_RecordCount = header.recordcount;
RecordLength = header.recordlength;
HeaderLength = header.headerlength;
ok = sanity_check(header);
break;
}
case Const.MAGIC_DBASE3:
case Const.MAGIC_DBASE3_MEMO:
case Const.MAGIC_DBASE3_MEMO_2:
case Const.MAGIC_FOXPRO:
default:
{
DBF_FILEHEADER_3 header = Utility.PtrToStructure <DBF_FILEHEADER_3>(bytes);
_RecordCount = header.recordcount;
RecordLength = header.recordlength;
HeaderLength = header.headerlength;
ok = sanity_check(header);
break;
}
}
if (ok)
{
if ((RecordCount == 0) && (RecordLength != 0))
{
_RecordCount = (stream.Length - HeaderLength) / RecordLength;
}
int fieldcount = (HeaderLength - (len_header + 1)) / len_field;
bytes = new byte[len_field];
for (int i = 0; i < fieldcount; i++)
{
ColumnInfo field;
StreamRead(stream, bytes);
if ((bytes[0] >= 0) && (bytes[0] <= (byte)' '))
{
break;
}
switch (version)
{
case Const.MAGIC_DBASE4:
case Const.MAGIC_DBASE4_MEMO:
{
DBF_FILEFIELD_4 item = Utility.PtrToStructure <DBF_FILEFIELD_4>(bytes);
DataType type = (DataType)Const.DataTypes.IndexOf(item.type);
field = new ColumnInfo()
{
Name = item.title, DataType = Convert.Type(type), Length = item.length, DecCount = item.deccount
};
break;
}
case Const.MAGIC_DBASE3:
case Const.MAGIC_DBASE3_MEMO:
case Const.MAGIC_DBASE3_MEMO_2:
case Const.MAGIC_FOXPRO:
default:
{
DBF_FILEFIELD_3 item = Utility.PtrToStructure <DBF_FILEFIELD_3>(bytes);
DataType type = (DataType)Const.DataTypes.IndexOf(item.type);
field = new ColumnInfo()
{
Name = item.title, DataType = Convert.Type(type), Length = item.length, DecCount = item.deccount
};
break;
}
}
Columns.Add(field);
}
}
}
}
}
if (ok)
{
_Stream = stream;
Filename = filename;
}
return(ok);
}
