/// <summary>
/// This Function Writes directly to a DBF File.
/// It reads the Field list, and writes to the correct position.
/// To access the deleted flag, use DELETED_FLAG as column Name
/// </summary>
/// <param name="dbfFile"></param>
/// <param name="column"></param>
/// <param name="row"></param>
/// <param name="value"></param>
/// <param name="ziphelper"></param>
/// <param name="dirSeperator"></param>
/// <returns></returns>
public static bool WriteValue(string dbfFile, string column, int row, object value, ZipHelper ziphelper, char dirSeperator)
{
//if (zipfile != null)
// throw new Exception("Write to Zipped Files is not supported!");
int bytesToRecordStart = 0;
long start = DateTime.Now.Ticks;
// If there isn't even a file, just return an empty DataTable
if ((false == ziphelper.FileExists(dbfFile)))
{
return false;
}
BinaryReader br = null;
BinaryWriter bw = null;
try
{
// Read the header into a buffer
Stream tmpStream = ziphelper.GetReadStream(dbfFile);
br = new BinaryReader(tmpStream);
byte[] completeBuffer = br.ReadBytes((int)ziphelper.GetStreamLength(dbfFile, tmpStream));
tmpStream.Close();
br.Close();
br = new BinaryReader(new MemoryStream(completeBuffer));
byte[] buffer = br.ReadBytes(Marshal.SizeOf(typeof(DBFHeader)));
// Marshall the header into a DBFHeader structure
GCHandle handle = GCHandle.Alloc(buffer, GCHandleType.Pinned);
DBFHeader header = (DBFHeader)Marshal.PtrToStructure(handle.AddrOfPinnedObject(), typeof(DBFHeader));
handle.Free();
// Read in all the field descriptors. Per the spec, 13 (0D) marks the end of the field descriptors
ArrayList fields = new ArrayList();
while ((13 != br.PeekChar()))
{
buffer = br.ReadBytes(Marshal.SizeOf(typeof(FieldDescriptor)));
handle = GCHandle.Alloc(buffer, GCHandleType.Pinned);
fields.Add((FieldDescriptor)Marshal.PtrToStructure(handle.AddrOfPinnedObject(), typeof(FieldDescriptor)));
handle.Free();
}
char writeFieldType = ' ';
int writeFieldLength = 0;
foreach (FieldDescriptor field in fields)
{
writeFieldType = (char)field.fieldType;
writeFieldLength = field.fieldLen;
if (field.fieldName == column)
break;
bytesToRecordStart += field.fieldLen;
}
br.Close();
Stream strm = ziphelper.GetWriteStream(dbfFile);
bw = new BinaryWriter(strm);
if (column != "DELETED_FLAG")
bytesToRecordStart++;
else
bytesToRecordStart = 0;
(/*(FileStream)*/ bw.BaseStream).Seek(header.headerLen + row*header.recordLen + bytesToRecordStart, SeekOrigin.Begin);
if (column == "DELETED_FLAG")
bw.Write((bool) value ? Encoding.ASCII.GetBytes("*") : Encoding.ASCII.GetBytes(" "));
else
{
/*
number = Encoding.ASCII.GetString(recReader.ReadBytes(field.fieldLen));
switch (field.fieldType)
{
case (byte)'N':
if (number.IndexOf(".") > -1)
{
col = new DataColumn(field.fieldName, typeof(decimal));
}
else
{
col = new DataColumn(field.fieldName, typeof(int));
}
break;
case (byte)'C':
col = new DataColumn(field.fieldName, typeof(string));
break;
case (byte)'T':
// You can uncomment this to see the time component in the grid
//col = new DataColumn(field.fieldName, typeof(string));
col = new DataColumn(field.fieldName, typeof(DateTime));
break;
case (byte)'D':
col = new DataColumn(field.fieldName, typeof(DateTime));
break;
case (byte)'L':
col = new DataColumn(field.fieldName, typeof(bool));
break;
case (byte)'F':
col = new DataColumn(field.fieldName, typeof(Double));
break;
case (byte)'M':
//Field Type Memo...
col = new DataColumn(field.fieldName, typeof(byte[]));
//col = new DataColumn(field.fieldName, typeof(string));
break;
}*/
switch (writeFieldType)
{
case 'N':
bw.Write(Encoding.ASCII.GetBytes(value.ToString().PadLeft(writeFieldLength, ' ')));
break;
case 'C':
bw.Write(Encoding.ASCII.GetBytes(value.ToString().PadRight(writeFieldLength, ' ')));
break;
default:
//br.Close();
return false;
}
}
ziphelper.WriteBackStream(dbfFile, strm);
bw.Close();
}
finally
{
if (br != null)
br.Close();
if (bw != null)
bw.Close();
}
return true;
}
