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

namespace DBUtilHelpV2Plus
{
  public static class DBToolV2Plus
  {
    /// <summary>
    /// 将DataTable导出到CSV.
    /// </summary>
    /// <param name=\"table\">DataTable</param>
    /// <param name=\"fullSavePath\">保存路径</param>
    /// <param name=\"tableheader\">标题信息</param>
    /// <param name=\"columname\">列名称『eg:姓名,年龄』</param>
    /// <returns>导出成功true;导出失败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>
    /// 参数检查
    /// </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(\"参数fullSavePath的值{0},不是正确的文件路径!\", fullSavePath));
      if (!_fileName.InvalidFileNameChars())
        throw new ArgumentException(string.Format(\"参数fullSavePath的值{0},包含非法字符!\", fullSavePath));
    }
    /// <summary>
    /// 将CSV文件数据导入到Datable中
    /// </summary>
    /// <param name=\"table\"></param>
    /// <param name=\"filePath\">DataTable</param>
    /// <param name=\"rowIndex\">保存路径</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导出到CSV文件{0}.\", testDb.ToCSV(fullSavePath, \"姓名,年龄\", \"人员信息表\") == true ? \"成功\" : \"失败\"));
        testDb.Rows.Clear();
        Console.WriteLine(string.Format(\"清空数据,当前{0}条数据.\", testDb.Rows.Count));
        testDb = testDb.AppendCSVRecord(fullSavePath, 2);
        Console.WriteLine(string.Format(\"CSV文件导入到Datable,导入{0}条数据.\", 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);
        }
      }
    }
  }
}