using System;
using System.Data;
using System.IO;
using System.Text;
using CSharpUtilHelpV2;
using StringUtilHelp;

namespace DBUtilHelpV2Plus
{
  public static class DBToolV2Plus
  {
    /// <summary>
    /// 將DataTable導出到CSV.
    /// </summary>
    /// <param name="table">DataTable</param>
    /// <param name="fullSavePath">保存路徑</param>
    /// <param name="tableheader">標題信息</param>
    /// <param name="columname">列名稱『eg:姓名,年齡』</param>
    /// <returns>導出成功true;導出失敗false</returns>
    public static bool ToCSV(this DataTable table, string fullSavePath, string tableheader, string columname)
    {
      ArgumentChecked(table, fullSavePath);
      //------------------------------------------------------------------------------------
      try
      {
        string _bufferLine = "";
        using (StreamWriter _writerObj = new StreamWriter(fullSavePath, false, Encoding.UTF8))
        {
          if (!string.IsNullOrEmpty(tableheader))
            _writerObj.WriteLine(tableheader);
          if (!string.IsNullOrEmpty(columname))
            _writerObj.WriteLine(columname);
          for (int i = 0; i < table.Rows.Count; i++)
          {
            _bufferLine = "";
            for (int j = 0; j < table.Columns.Count; j++)
            {
              if (j > 0)
                _bufferLine += ",";
              _bufferLine += table.Rows[i][j].ToString();
            }
            _writerObj.WriteLine(_bufferLine);
          }
          return true;
        }
      }
      catch (Exception)
      {
        return false;
      }
    }
    /// <summary>
    /// 參數(shù)檢查
    /// </summary>
    /// <param name="table"></param>
    /// <param name="fullSavePath"></param>
    private static void ArgumentChecked(DataTable table, string fullSavePath)
    {
      if (table == null)
        throw new ArgumentNullException("table");
      if (string.IsNullOrEmpty(fullSavePath))
        throw new ArgumentNullException("fullSavePath");
      string _fileName = CSharpToolV2.GetFileNameOnly(fullSavePath);
      if (string.IsNullOrEmpty(_fileName))
        throw new ArgumentException(string.Format("參數(shù)fullSavePath的值{0},不是正確的文件路徑!", fullSavePath));
      if (!_fileName.InvalidFileNameChars())
        throw new ArgumentException(string.Format("參數(shù)fullSavePath的值{0},包含非法字符!", fullSavePath));
    }
    /// <summary>
    /// 將CSV文件數(shù)據(jù)導入到Datable中
    /// </summary>
    /// <param name="table"></param>
    /// <param name="filePath">DataTable</param>
    /// <param name="rowIndex">保存路徑</param>
    /// <returns>Datable</returns>
    public static DataTable AppendCSVRecord(this DataTable table, string filePath, int rowIndex)
    {
      ArgumentChecked(table, filePath);
      if (rowIndex < 0)
        throw new ArgumentException("rowIndex");
      using (StreamReader reader = new StreamReader(filePath, Encoding.UTF8, false))
      {
        int i = 0, j = 0;
        reader.Peek();
        while (reader.Peek() > 0)
        {
          j = j + 1;
          string _line = reader.ReadLine();
          if (j >= rowIndex + 1)
          {
            string[] _split = _line.Split(',');
            DataRow _row = table.NewRow();
            for (i = 0; i < _split.Length; i++)
            {
              _row[i] = _split[i];
            }
            table.Rows.Add(_row);
          }
        }
        return table;
      }
    }
  }
}

using System;
using System.Data;
using DBUtilHelpV2;
using DBUtilHelpV2Plus;
namespace DBUtilHelpV2PlusTest
{
  class Program
  {
    static DataTable testDb = null;
    static string fullSavePath = string.Format(@"C:\{0}.csv", DateTime.Now.ToString("yyyyMMddHH"));
    static void Main(string[] args)
    {
      try
      {
        CreateTestDb();
        Console.WriteLine(string.Format("DataTable導出到CSV文件{0}.", testDb.ToCSV(fullSavePath, "姓名,年齡", "人員信息表") == true ? "成功" : "失敗"));
        testDb.Rows.Clear();
        Console.WriteLine(string.Format("清空數(shù)據(jù),當前{0}條數(shù)據(jù).", testDb.Rows.Count));
        testDb = testDb.AppendCSVRecord(fullSavePath, 2);
        Console.WriteLine(string.Format("CSV文件導入到Datable,導入{0}條數(shù)據(jù).", testDb.Rows.Count));
      }
      catch (Exception ex)
      {
        Console.WriteLine(ex.Message);
      }
      finally
      {
        Console.ReadLine();
      }
    }
    static void CreateTestDb()
    {
      if (testDb == null)
      {
        testDb = DBToolV2.CreateTable("Name,Age|int");
        for (int i = 1; i <= 10; i++)
        {
          DataRow _row = testDb.NewRow();
          _row["Name"] = string.Format("YanZhiwei_{0}", i);
          _row["Age"] = i;
          testDb.Rows.Add(_row);
        }
      }
    }
  }
}