首先，需要添加引用Excel.dll，Excel组件VS.Net本身是没有的，以下是生成Excel.dll的方法。

1.要保证机器本身要安装Microsoft Office。

2.把C:Program FilesMicrosoft OfficeOffice1:【office 安装路径】下的EXCEL9.OLB文件拷贝到C:Visual Studio.NetSDKv1.1Bin:【VS.Net安装路径】路径下。

3.打开Visual Studio .Net2003/2008命令提示，运行TlbImp Excel9.olb Excel.dll ，就会在[C:Visual Studio.NetSDKv1.1Bin]下生成Excel.dll组件。(Tlbimp命令是vs自带的一个工具，位于Microsoft Visual Studio 8SDKv2.0Bin下)

4.把Excel.dll复制到你的项目中，在项目中添加Excel.dll引用就可以了。(最好是用最新版本的Office生成excel.dll，否则旧版本的office的dll有可能在高版本机器上不兼容。)

以下是把一个dataset中的数据导出到excel的实例：

记得在解决方案资源管理器中添加excel.dll的引用后，在用此函数的时候在顶部 using Excel;

public void ExportExcel(DataSet ds)
        {
            if (ds == null) return;

            string saveFileName = "";
            bool fileSaved = false;
            SaveFileDialog saveDialog = new SaveFileDialog();
            saveDialog.DefaultExt = "xls";
            saveDialog.Filter = "Excel文件|*.xls";
            saveDialog.FileName = "Sheet1";
            saveDialog.ShowDialog();
            saveFileName = saveDialog.FileName;
            if (saveFileName.IndexOf(":") < 0) return; //被点了取消

            Excel.Application xlApp = new Excel.Application();

            if (xlApp == null)
            {
                MessageBox.Show("无法创建Excel对象，可能您的机子未安装Excel");
                return;
            }

            Excel.Workbooks workbooks = xlApp.Workbooks;
            Excel.Workbook workbook = workbooks.Add(Excel.XlWBATemplate.xlWBATWorksheet);
            Excel.Worksheet worksheet = (Excel.Worksheet)workbook.Worksheets[1];//取得sheet1
            Excel.Range range;

            string oldCaption = DateTime.Today.ToString("yy-MM-dd");
            long totalCount = ds.Tables[0].Rows.Count;
            long rowRead = 0;
            float percent = 0;

            worksheet.Cells[1, 1] = DateTime.Today.ToString("yy-MM-dd");
            //写入字段
            for (int i = 0; i < ds.Tables[0].Columns.Count; i++)
            {
                worksheet.Cells[2, i + 1] = ds.Tables[0].Columns[i].ColumnName;
                range = (Excel.Range)worksheet.Cells[2, i + 1];
                range.Interior.ColorIndex = 15;
                range.Font.Bold = true;

            }
            //写入数值

              for (int r = 0; r < ds.Tables[0].Rows.Count; r++)
            {
                for (int i = 0; i < ds.Tables[0].Columns.Count; i++)
                {
                    worksheet.Cells[r + 3, i + 1] = ds.Tables[0].Rows[r][i];
                }
                rowRead++;
                percent = ((float)(100 * rowRead)) / totalCount;
                //this.lbl_process.Text = "正在导出数据[" + percent.ToString("0.00") + "%]..."; //这里可以自己做一个label用来显示进度.
               System.Windows.Forms.Application.DoEvents();
            }
            this.lbl_process.Visible = false;

            range = worksheet.get_Range(worksheet.Cells[2, 1], worksheet.Cells[ds.Tables[0].Rows.Count + 2, ds.Tables[0].Columns.Count]);
            range.BorderAround(Excel.XlLineStyle.xlContinuous, Excel.XlBorderWeight.xlThin, Excel.XlColorIndex.xlColorIndexAutomatic, null);

            range.Borders[Excel.XlBordersIndex.xlInsideHorizontal].ColorIndex = Excel.XlColorIndex.xlColorIndexAutomatic;
            range.Borders[Excel.XlBordersIndex.xlInsideHorizontal].LineStyle = Excel.XlLineStyle.xlContinuous;
            range.Borders[Excel.XlBordersIndex.xlInsideHorizontal].Weight = Excel.XlBorderWeight.xlThin;

            if (ds.Tables[0].Columns.Count > 1)
            {
                range.Borders[Excel.XlBordersIndex.xlInsideVertical].ColorIndex = Excel.XlColorIndex.xlColorIndexAutomatic;
                range.Borders[Excel.XlBordersIndex.xlInsideVertical].LineStyle = Excel.XlLineStyle.xlContinuous;
                range.Borders[Excel.XlBordersIndex.xlInsideVertical].Weight = Excel.XlBorderWeight.xlThin;
            }

            if (saveFileName != "")
            {
                try
                {
                    workbook.Saved = true;
                    workbook.SaveCopyAs(saveFileName);
                    fileSaved = true;
                }
                catch (Exception ex)
                {
                    fileSaved = false;
                    MessageBox.Show("导出文件时出错,文件可能正被打开！n" + ex.Message);
                }
            }
            else
            {
                fileSaved = false;
            }
            xlApp.Quit();
            GC.Collect();//强行销毁
            if (fileSaved && File.Exists(saveFileName))
            {
                //System.Diagnostics.Process.Start(saveFileName);
                MessageBox.Show("导出成功！","通知");
            }
        }