C#导出数据到CSV文件的通用类实例

本文实例讲述了c#导出数据到csv文件的通用类。分享给大家供大家参考。具体如下：

通过这个类可以很简单的定义数据格式，并导出到csv文件

//这里写了一个通用的类
using system;
using system.data;
using system.configuration;
using system.collections.generic;
using system.web;
using system.web.security;
using system.web.ui;
using system.web.ui.webcontrols;
using system.web.ui.webcontrols.webparts;
using system.web.ui.htmlcontrols;
using system.text;
using system.reflection;
using system.io;
using system.data.odbc;
namespace com.drpeng.sdxy.ui.common
{
 public class csvhelper
 {
  #region fields
  string _filename;
  datatable _datasource;//数据源
  string[] _titles = null;//列标题
  string[] _fields = null;//字段名
  #endregion
  #region .ctor
  /// <summary> 
  /// 构造函数 
  /// </summary> 
  /// <param name="datasource">数据源</param> 
  public csvhelper()
  {
  }
  /// <summary> 
  /// 构造函数 
  /// </summary> 
  /// <param name="titles">要输出到 excel 的列标题的数组</param> 
  /// <param name="fields">要输出到 excel 的字段名称数组</param> 
  /// <param name="datasource">数据源</param> 
  public csvhelper(string[] titles, string[] fields, datatable datasource)
   : this(titles, datasource)
  {
   if (fields == null || fields.length == 0)
    throw new argumentnullexception("fields");
   if (titles.length != fields.length)
    throw new argumentexception("titles.length != fields.length", "fields");
   _fields = fields;
  }
  /// <summary> 
  /// 构造函数 
  /// </summary> 
  /// <param name="titles">要输出到 excel 的列标题的数组</param> 
  /// <param name="datasource">数据源</param> 
  public csvhelper(string[] titles, datatable datasource)
   : this(datasource)
  {
   if (titles == null || titles.length == 0)
    throw new argumentnullexception("titles");
   _titles = titles;
  }
  /// <summary> 
  /// 构造函数 
  /// </summary> 
  /// <param name="datasource">数据源</param> 
  public csvhelper(datatable datasource)
  {
   if (datasource == null)
    throw new argumentnullexception("datasource");
   // maybe more checks needed here (ienumerable, ilist, ilistsource, ) ??? 
   // 很难判断，先简单的使用 datatable 
   _datasource = datasource;
  }
  #endregion
  #region public methods
  #region 导出到csv文件并且提示下载
  /// <summary>
  /// 导出到csv文件并且提示下载
  /// </summary>
  /// <param name="filename"></param>
  public void datatocsv(string filename)
  {
   // 确保有一个合法的输出文件名 
   //if (filename == null || filename == string.empty || !(filename.tolower().endswith(".csv")))
   // filename = getrandomfilename();
   string data = exportcsv();
   httpcontext.current.response.clearheaders();
   httpcontext.current.response.clear();
   httpcontext.current.response.expires = 0;
   httpcontext.current.response.bufferoutput = true;
   httpcontext.current.response.charset = "gb2312";
   httpcontext.current.response.contentencoding = system.text.encoding.getencoding("gb2312");
   httpcontext.current.response.appendheader("content-disposition", string.format("attachment;filename={0}.csv", system.web.httputility.urlencode(filename, system.text.encoding.utf8)));
   httpcontext.current.response.contenttype = "text/h323;charset=gbk";
   httpcontext.current.response.write(data);
   httpcontext.current.response.end();
  }
  #endregion
  /// <summary>
  /// 获取csv导入的数据
  /// </summary>
  /// <param name="filepath">文件路径</param>
  /// <param name="filename">文件名称(.csv不用加)</param>
  /// <returns></returns>
  public datatable getcsvdata(string filepath,string filename)
  {
   string path = path.combine(filepath, filename + ".csv");
   string connstring = @"driver={microsoft text driver (*.txt; *.csv)};dbq=" + filepath + ";extensions=asc,csv,tab,txt;";
   try
   {
    using (odbcconnection odbcconn = new odbcconnection(connstring))
    {
     odbcconn.open();
     odbccommand olecomm = new odbccommand();
     olecomm.connection = odbcconn;
     olecomm.commandtext = "select * from [" + filename + "#csv]";
     odbcdataadapter adapter = new odbcdataadapter(olecomm);
     dataset ds = new dataset();
     adapter.fill(ds, filename);
     return ds.tables[0];
     odbcconn.close();
    }
    if (file.exists(path))
    {
     file.delete(path);
    }
   }
   catch (exception ex)
   {
    if (file.exists(path))
    {
     file.delete(path);
    }
    throw ex;
   }
  }
  #endregion
  #region 返回写入csv的字符串
  /// <summary>
  /// 返回写入csv的字符串
  /// </summary>
  /// <returns></returns>
  private string exportcsv()
  { 
   if(_datasource==null)
    throw new argumentnullexception("datasource");
   stringbuilder strbdata = new stringbuilder();
   if (_titles == null)
   {
    //添加列名
    foreach (datacolumn column in _datasource.columns)
    {
     strbdata.append(column.columnname + ",");
    }
    strbdata.append("\n");
    foreach (datarow dr in _datasource.rows)
    {
     for (int i = 0; i < _datasource.columns.count; i++)
     {
      strbdata.append(dr[i].tostring() + ",");
     }
     strbdata.append("\n");
    }
    return strbdata.tostring();
   }
   else
   {
    foreach (string columnname in _titles)
    {
     strbdata.append(columnname + ",");
    }
    strbdata.append("\n");
    if (_fields == null)
    {
     foreach (datarow dr in _datasource.rows)
     {
      for (int i = 0; i < _datasource.columns.count; i++)
      {
       strbdata.append(dr[i].tostring() + ",");
      }
      strbdata.append("\n");
     }
     return strbdata.tostring();
    }
    else
    {
     foreach (datarow dr in _datasource.rows)
     {
      for (int i = 0; i < _fields.length; i++)
      {
       strbdata.append(_fields[i].tostring() + ",");
      }
      strbdata.append("\n");
     }
     return strbdata.tostring();
    }
   }
  }
  #endregion
  #region 得到一个随意的文件名
  /// <summary> 
  /// 得到一个随意的文件名 
  /// </summary> 
  /// <returns></returns> 
  private string getrandomfilename()
  {
   random rnd = new random((int)(datetime.now.ticks));
   string s = rnd.next(int32.maxvalue).tostring();
   return datetime.now.toshortdatestring() + "_" + s + ".csv";
  }
  #endregion
 }
}

希望本文所述对大家的c#程序设计有所帮助。