c# dbf

/*Header.cs*/

namespace CSharpdbf
{
    public class Header
    {
        public string FieldName = string.Empty; //字段名称,ASCII码   0-9  
       public char Reserved1;//保留字节   10  
       public char FieldType;//字段类型,CDNL等ASCII码11  
       public long Offset;//本字段在首记录中的位置   12-15  
       public char FieldLength;//字段长度<=256   16  
       public char Decimal;//小数点的位数   17  
       public string Reserved =string.Empty;//保留       18-31    (14个字节 )
    }
}

/*FileInfo.cs*/

namespace CSharpdbf
{

    public class FileInfo
    {
        public char Mark;   //0x03h   或   0x80h(有MEMORY字段)   0   
        public char Year, Mmonth, Day;//依次为年月日,二进制   1-3  
        public long RecordCount;//总记录个数,低位字节在前   4-7  
        public short HeaderLength;//文件头长度=第9字节值*256+第8字节值   8-9  
        public short RecordLength;//记录长度=第11字节值*256+第10字节值   10-11  
        public string Reserved=string.Empty ;//保留   12-31   (20 个字节)

    }
}

/*DBFDocument.cs*/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.IO;
using System.Data.OleDb;

namespace CSharpdbf
{
    public class DBFDocument
    {

        FileInfo fileInfo = new FileInfo();
        List<Header> headers = new List<Header>();
        byte[] dbfBuffer;
        public DataTable Data
        {
            get
            {
                return GetData();
            }
        }

        public DataTable GetData()
        {
            DataTable dataTable = new DataTable();
            DataColumn dataColumn;
            foreach (Header header in headers)
            {
                dataColumn = new DataColumn(header.FieldName);
                dataTable.Columns.Add(dataColumn);
            }

            DataRow dataRow;
            int fiekdCount = headers.Count;

            for (int i = 0; i < GetRecordCount(); i++)
            {
                dataRow = dataTable.NewRow();
                for (int j = 0; j < fiekdCount; j++)
                {

                    dataRow[j] = GetRecordFieldValue(i + 1, j + 1);
                }
                dataTable.Rows.Add(dataRow);
            }

            return dataTable;
        }

        #region Initialization

        /// <summary>
        /// //填充FILEHEADER和INFOHEADER  
        /// </summary>
        /// <param name="filename"></param>
        /// <returns></returns>
        public void LoadFile(string filename)
        {
            using (FileStream fileStream = File.Open(filename, FileMode.Open))
            {
                dbfBuffer = new byte[fileStream.Length];
                fileStream.Read(dbfBuffer, 0, dbfBuffer.Length);
            }
            FillFileInfo();
            FillHeadInfos();
        }

        /// <summary>
        /// 读取文件信息
        /// </summary>
        private void FillFileInfo()
        {
            fileInfo.Mark = (char)dbfBuffer[0];
            fileInfo.Year = (char)dbfBuffer[1];
            fileInfo.Mmonth = (char)dbfBuffer[2];
            fileInfo.Day = (char)dbfBuffer[3];
            byte[] bt = new byte[4];
            for (int i = 4; i < 8; i++)
            {
                bt[i - 4] = dbfBuffer[i];
            }
            fileInfo.RecordCount = BitConverter.ToInt32(bt, 0);

 

            bt = new byte[2];
            for (int i = 8; i < 10; i++)
            {
                bt[i - 8] = dbfBuffer[i];
            }
            fileInfo.HeaderLength = BitConverter.ToInt16(bt, 0);

 

            bt = new byte[2];
            for (int i = 10; i < 12; i++)
            {
                bt[i - 10] = dbfBuffer[i];
            }
            fileInfo.RecordLength = BitConverter.ToInt16(bt, 0);

            fileInfo.Reserved = System.Text.Encoding.Default.GetString(dbfBuffer, 11, 20);
        }

        /// <summary>
        /// 读取字段信息。
        /// </summary>
        private void FillHeadInfos()
        {
            for (int i = 0; ; i++)
            {
                if ((int)dbfBuffer[(i + 1) * 32] == 0x0D || i >= GetFieldCount())
                {
                    break;
                }

                byte[] buff = new byte[32];
                for (int j = (i + 1) * 32; j < (i + 1) * 32 + 32; j++)
                {
                    buff[j - (i + 1) * 32] = dbfBuffer[j];
                }

                Header dBFInfoHeader = new Header();
                FillHeaderInfo(ref dBFInfoHeader, buff, (i + 1) * 32);
                headers.Add(dBFInfoHeader);
            }

        }

        #endregion

        //获取字段个数
        private int GetFieldCount()
        {
            return (fileInfo.HeaderLength / 32 - 1);
        }

        //获取任一字段名
        private string GetFieldName(int FieldNum)
        {
            if (FieldNum < 1 || FieldNum > headers.Count) return null;

            if (FieldNum < 1) return "";

            return headers[FieldNum - 1].FieldName;
        }

        //获取任一字段长度  
        private int GetFieldLength(int FieldNum)
        {
            if (FieldNum < 1) return -1;

            return (headers[FieldNum - 1].FieldLength);
        }

        //获取任一字段类型  
        private string GetFieldType(int FieldNum)
        {
            if (FieldNum < 1) return "#";
            return new string(new char[] { headers[FieldNum - 1].FieldType });
        }

        //获取任一数值型字段小数点位数  
        private int GetDecimal(int FieldNum)
        {
            if (FieldNum < 1) return -1;

            return (int)headers[FieldNum - 1].Decimal;
        }

        private long GetRecordCount()
        {
            return fileInfo.RecordCount;
        }

        //获取记录长度  
        private int GetRecordLength()
        {
            return (fileInfo.RecordLength);
        }

        //获取任一记录  
        private string GetRecord(int RecordNum)
        {
            if (RecordNum < 1) return "";
            int lPos = fileInfo.HeaderLength + 1 + (RecordNum - 1) * (GetRecordLength());
            string aaa = System.Text.Encoding.Default.GetString(dbfBuffer, lPos, GetRecordLength() - 1);

            return aaa;
        }

        //获取任一记录的任一字段值  
        private string GetRecordFieldValue(int RecordNum, int FieldNum)
        {
            if (RecordNum < 1 || FieldNum < 1) return "";

            int lPos = fileInfo.HeaderLength + 1 + (RecordNum - 1) * (GetRecordLength());

            for (int i = 1; (i < FieldNum) && (i <= headers.Count); i++)
            {
                lPos += GetFieldLength(i);
            }

            string aaa = System.Text.Encoding.Default.GetString(dbfBuffer, lPos, GetFieldLength(FieldNum));

            return aaa;

        }

        /// <summary>
        /// 填充字段信息。
        /// </summary>
        /// <param name="dbfInfoHeader"></param>
        /// <param name="buffer"></param>
        /// <param name="position"></param>
        private void FillHeaderInfo(ref Header dbfInfoHeader, byte[] buffer, int position)
        {

            dbfInfoHeader.FieldName = System.Text.Encoding.Default.GetString(buffer, 0, 9);

            dbfInfoHeader.Reserved1 = (char)buffer[10];

            dbfInfoHeader.FieldType = (char)buffer[11];

            byte[] bys = new byte[4];

            for (int i = 12; i < 16; i++)
            {
                bys[i - 12] = buffer[i];
            }
            dbfInfoHeader.Offset = BitConverter.ToInt32(bys, 0);

            dbfInfoHeader.FieldLength = (char)buffer[16];
            dbfInfoHeader.Decimal = (char)buffer[17];

            dbfInfoHeader.Reserved = System.Text.Encoding.Default.GetString(buffer, 18, 14);
        }

        //public DataTable Read(string fileName)
        //{
        //    string dir = Path.GetDirectoryName(fileName);
        //    string tableName = Path.GetFileName(fileName);

        //    System.Data.Odbc.OdbcConnection odbc = new System.Data.Odbc.OdbcConnection("Driver={Microsoft Visual FoxPro Driver};SourceType=DBF;SourceDB=" + dir + ";Exclusive=No; Collate=Machine;NULL=NO;DELETED=NO;BACKGROUNDFETCH=NO;");
        //    odbc.Open();
        //    DataTable dtQY = new DataTable();
        //    System.Data.Odbc.OdbcDataAdapter oadapt = new System.Data.Odbc.OdbcDataAdapter();

        //    oadapt.SelectCommand = new System.Data.Odbc.OdbcCommand("select * from " + tableName, odbc);

        //    oadapt.Fill(dtQY);
        //    oadapt.Dispose();

        //    oadapt.Dispose();
        //    odbc.Close();

        //    return dtQY;

        //}

    }
}