public bool Create(string filename, List <ColumnInfo> fields)
{
FileMode mode = FileMode.Create;
FileAccess access = FileAccess.ReadWrite; // exclusive
string filename_memo = string.Empty;
bool memo = false;
foreach (ColumnInfo item in fields)
{
memo = memo || (Convert.Type(item.DataType, item.Length) == DataType.Memo);
}
FileStream stream = new FileStream(filename, mode, access);
FileStream stream_memo = null;
bool ok = (stream != null);
if (ok && memo)
{
filename_memo = MemoFile.CreateFileName(filename);
stream_memo = new FileStream(filename_memo, mode, access);
ok = (stream_memo != null);
}
if (ok)
{
byte[] bytes;
ok = Attach(stream, filename, false);
if (ok)
{
HeaderLength = Const.DefaultHeaderLen + Const.FieldTerminatorLen + Const.DefaultFieldLen * fields.Count;
IsDirty = true;
stream.SetLength(HeaderLength);
StreamSeek(stream, Const.DefaultHeaderLen);
Columns = fields;
RecordLength = Const.RECORD_POS_DATA;
foreach (ColumnInfo item in fields)
{
DBF_FILEFIELD_3 field = new DBF_FILEFIELD_3();
if (item.Name.Length > Const.FieldNameLen)
{
throw new Exception("Name too long");
}
field.title = item.Name;
field.type = Const.DataTypes[(int)Convert.Type(item.DataType, item.Length)];
field.length = (byte)item.Length;
field.deccount = (byte)item.DecCount;
bytes = Utility.StructureToPtr <DBF_FILEFIELD_3>(field);
StreamWrite(stream, bytes);
RecordLength += item.Length;
}
bytes = new byte[] { (byte)Const.FieldTerminator };
StreamWrite(stream, bytes);
}
if (stream_memo != null)
{
AttachMemo(stream_memo, filename_memo);
}
}
return(ok);
}
public bool Attach(Stream 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);
}
