DbfFieldDescriptor ReadFieldDescriptor(BinaryReader br, int fdNo)
{
var fieldDescriptor = new DbfFieldDescriptor();
fieldDescriptor.No = fdNo;
try
{
var fieldNameBytes = new byte[11];
fieldNameBytes[0] = br.ReadByte();
if (fieldNameBytes[0] == 0x0D)
{
return(null); // 0x0D means end of field descriptor list
}
br.Read(fieldNameBytes, 1, 10);
fieldDescriptor.Name = System.Text.Encoding.ASCII.GetString(fieldNameBytes).TrimEnd('\0');
fieldDescriptor.TypeChar = (char)br.ReadByte();
br.ReadByte(); // reserved
br.ReadByte(); // reserved
br.ReadByte(); // reserved
br.ReadByte(); // reserved
fieldDescriptor.Length = br.ReadByte();
fieldDescriptor.DecimalCount = br.ReadByte();
br.ReadBytes(2); // work area id
br.ReadByte(); // example
br.ReadBytes(10); // reserved
br.ReadByte(); // production mdx
return(fieldDescriptor);
}
catch (Exception e)
{
if (string.IsNullOrWhiteSpace(fieldDescriptor.Name))
{
throw new Exception($"Failed to read field descriptor #{fdNo + 1}", e);
}
else
{
throw new Exception($"Failed to read field descriptor #{fdNo + 1} ({fieldDescriptor.Name})", e);
}
}
}
private object ReadField(DbfFieldDescriptor fd)
{
var data = binaryReader.ReadBytes(fd.Length);
switch (fd.TypeChar)
{
case 'C':
return(ReadFieldText(data));
case 'I':
return(ReadFieldInteger(data));
case 'N':
return(ReadFieldNumeric(data));
case 'L':
return(ReadFieldLogical(data));
case 'D':
return(ReadFieldDate(data));
case 'M':
return(ReadFieldMemo(data));
case 'T':
return(ReadFieldTime(data));
case 'W': //?
return(null);
case '0'
: // _NullFlags? https://stackoverflow.com/questions/30886730/adding-data-to-dbf-file-adds-column-nullflags
return(null);
}
throw new NotSupportedException($"Field type ({fd.TypeChar})");
}
public ObjectToDbfTypeMap(DbfFieldDescriptor fieldType, Func <T, object> mapFunction)
{
FieldType = fieldType;
MapFunction = mapFunction;
}
