C#中csv文件与DataTable互相导入处理实例解析

本文介绍了c#中csv文件与datatable互相导入处理实例解析，主要功能代码封装处理下，相对比较简单。以后项目用到的话可以直接使用。具体方法如下：

1.封装好的类如下：

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;
      }
    }
  }
}

2.代码使用测试如下：

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);
        }
      }
    }
  }
}

运行效果如下图所示：