收集了两种方法，一种是直接利用I/o读写去生成非标准格式的xls文件，速度很快。另外种就是直接使用EXCEL的COM组件实现，需要在项目中引用EXCEL的COM组件。

IO方法：

public void exportFromDataTable(System.Data.DataTable dt, string pathName)        {            FileStream objFileStream;            StreamWriter objStreamWriter;            string strLine = " ";            objFileStream = new FileStream(pathName, FileMode.OpenOrCreate, FileAccess.Write);            objStreamWriter = new StreamWriter(objFileStream, System.Text.Encoding.Unicode);            //循环写入列头名称            for (int i = 0; i < dt.Columns.Count; i++)            {                 strLine = strLine + dt.Columns[i].ColumnName.ToString() + Convert.ToChar(9);            }            objStreamWriter.WriteLine(strLine);            strLine = " ";            //循环写入内容            for (int i = 0; i < dt.Rows.Count; i++)            {                strLine = strLine + (i + 1) + Convert.ToChar(9);                for (int j = 1; j < dt.Columns.Count; j++)                {                    strLine = strLine + dt.Rows[i][j].ToString() + Convert.ToChar(9);                }                objStreamWriter.WriteLine(strLine);                strLine = " ";            }            objStreamWriter.Close();            objFileStream.Close();        }

COM组件方法：

public void ExportToExcelByExcel(System.Data.DataTable dt, string pathName)        {            object objOpt = System.Reflection.Missing.Value;            Excel.Application excel = new Excel.Application();            excel.Visible = true;            Workbook wkb = excel.Workbooks.Add(objOpt);            Worksheet wks = (Worksheet)wkb.ActiveSheet;            wks.Visible = XlSheetVisibility.xlSheetVisible;            int rowIndex = 1;            int colIndex = 0;            System.Data.DataTable table = dt;            foreach (DataColumn col in table.Columns)            {                colIndex++;                excel.Cells[1, colIndex] = col.ColumnName;            }            foreach (DataRow row in table.Rows)            {                rowIndex++;                colIndex = 0;                foreach (DataColumn col in table.Columns)                {                    colIndex++;                    excel.Cells[rowIndex, colIndex] = row[col.ColumnName].ToString();                }            }            try            {                wkb.SaveAs(pathName, objOpt, null, null, false, false, XlSaveAsAccessMode.xlNoChange, ConflictOption.OverwriteChanges, null, null, null, null);            }            catch (Exception ex)            {                throw new Exception(ex.Message);            }            finally            {                wkb.Close(false, objOpt, objOpt);                excel.Quit();            }        }

引用3个DLL：Interop.Excel.dll，Interop.VBIDE.dll，Interop.Office.dll（下载地址见下）

在项目中：using Excel;

下载：

 

调用示例方法如下：

　　　　　　  if (saveFileDialog1.ShowDialog() == DialogResult.OK)                {                    ExportToExcel excel = new ExportToExcel();                    excel.exportFromDataTable((DataTable)dataGridViewX1.DataSource, saveFileDialog1.FileName);                    MessageBox.Show("成功");                }