sql server数据导入到excel

        private void btnDownloadExcel_Click(object sender, EventArgs e)
        {
            lblMsg.Text = "";
            string saveFilePath = txtQueryFilePath.Text;
            if (saveFilePath == "")
            {
                lblMsg.Text = "请输入保存excel的路径!";
                return;
            }
          
            try
            {
                progressBar1.Value=1;
              
                string sql = rTxtQuerySql.Text;
                if (sql == "")
                {
                    lblMsg.Text = "请输入查询语句!";
                    return;
                }
                string strConn = ConfigurationManager.ConnectionStrings["strConn"].ToString();
                SqlConnection conn = new SqlConnection(strConn);
                conn.Open();
                // string sql="select *from GroupCode";
                //string sql = "select * From scrap where statusflag='7' and apptime between '2009-06-01' and '2009-06-30'";

                SqlDataAdapter da = new SqlDataAdapter(sql, conn);
                DataSet ds = new DataSet();
                da.Fill(ds, "table1");
                conn.Close();
                System.Data.DataTable dt = new System.Data.DataTable();
                dt = ds.Tables[0];


                Microsoft.Office.Interop.Excel.Application excelApp = new Microsoft.Office.Interop.Excel.ApplicationClass();//Application与ApplicationClass的区别我没有明白。          

                Workbook excelBook = excelApp.Workbooks.Add(Type.Missing);
                Worksheet excelSheet = (Worksheet)excelBook.ActiveSheet;

                int rowCount = dt.Rows.Count;               
                int colCount = dt.Columns.Count;
                progressBar1.Maximum = rowCount*colCount + 10;
                progressBar1.Step = 1;
                object[,] dataArray = new object[rowCount + 1, colCount];//二维数组定义是多一个标题行。

                for (int j = 0; j < colCount; j++)
                {
                    dataArray[0, j] = dt.Columns[j].Caption;//导出字段标题。
                    for (int i = 0; i < rowCount; i++)
                    {
                        dataArray[i + 1, j] = dt.Rows[i][j];
                        progressBar1.PerformStep();
                        //progressBar1.Value = progressBar1.Value + 1;
                    }
                  
                }
                // excelSheet.get_Range(excelSheet.Cells[startRow, startCol], excelSheet.Cells[rowCount + startRow, colCount + startCol - 1]).Value2 = dataArray;

                excelSheet.get_Range("A1", excelSheet.Cells[rowCount + 1, colCount]).Value2 = dataArray;
               // excelApp.Visible = true;            
                excelBook.SaveAs(saveFilePath, Microsoft.Office.Interop.Excel.XlFileFormat.xlExcel9795, null, null, false, false, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlNoChange, null, null, null, null, null);
 
                excelApp.Quit();              
                GC.Collect();
             
                lblMsg.Text ="共"+rowCount+ "行数据成功导入到excel,保存在" + saveFilePath;
               
            }
            catch (Exception ex)
            {
                progressBar1.Minimum = 0;
                lblMsg.Text = ex.Message;
            }        

            

        }