首先要在工程中添加com引用，选择Microsoft Excel 11.0 Object Liberty。

源代码如下（本例是在下生成公司的考勤表 测试代码）：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
using Microsoft.Office.Interop.Excel;
using System.IO;
//using Microsoft.Office.Interop.Excel;

namespace AttToExcel
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application();
int rowIndex = 1;
int colIndex = 0;
excel.Application.Workbooks.Add(true);
System.Data.DataTable table = GetData();
// dealTable(table);

//将所得到的表的列名,赋值给单元格
foreach (DataColumn col in table.Columns)
{
colIndex++;
excel.Cells[1, colIndex] = col.ColumnName;
}


//同样方法处理数据
foreach (DataRow row in table.Rows)
{
rowIndex++;
colIndex = 0;
foreach (DataColumn col in table.Columns)
{
colIndex++;
excel.Cells[rowIndex, colIndex] = row[col.ColumnName].ToString();
}
}

Worksheet ws = (Worksheet)excel.ActiveSheet;
AutoFitColumn(ws, 5);
//true则直接用excel打开得到的数据
excel.Visible = true ;

}
//进行加班处理
private void dealTable(System.Data.DataTable table)
{

}
//让excel列宽自适应宽度
public static void AutoFitColumn(Worksheet ws, int col)
{
((Range)ws.Cells[1, col]).EntireColumn.AutoFit();
}
//获取数据库打卡记录数据
private System.Data.DataTable GetData()
{
SqlConnection conn= new SqlConnection(@"Server=127.0.0.1;Initial Catalog=attendance;Uid=sa;Pwd=123456;");
String sqlText = "select "+
"EmplId as '员工ID',"+
"(select EmplName from HrEmployee where HrEmployee.EmplID=AtdProcRec.EmplID) as '姓名',"+

"case "+
"when min(RecTime)<'07:00' then max(RecTime) "+
" else min(RecTime) "+
" end as '上班时间', "+

"case when min(RecTIme)<'07:00' then min(RecTime) "+
" else max(RecTime) "+
" end as '下班时间', "+

"ResultDate as '结果日期'"+
" from dbo.AtdProcRec"+
" where EmplID=34 "+
"group by ResultDate,EmplId";//+
//"having min(RecTime)>'09:00' or max(Rectime)<'17:30'";
SqlDataAdapter adapter = new SqlDataAdapter(sqlText, conn);

DataSet ds= new DataSet();
try
{
adapter.Fill(ds,"Customer");
}
catch(Exception ex)
{
MessageBox.Show(ex.ToString());
}
return ds.Tables[0];
}//end GetData()

}//end public partial class
}//end namespace