ASP. NET convert dt to excel online download

1. Methods

      PrivateStringWriter getstringwriter (DataTable dt) {StringWriter SW=NewStringWriter (); //Read Column name            foreach(DataColumn DCinchdt. Columns) SW. Write (DC. ColumnName+"\ t"); //Read column values//a re-lineSW. Write (SW.            NewLine); if(dt! =NULL)            {                foreach(DataRow Drinchdt. Rows) { for(inti =0; i < dt. Columns.count; i++) {SW. Write (Dr[i]. ToString ()+"\ t"); } SW. Write (SW.                NewLine); }} SW.            Close (); returnSW; }        protected voidExcelimport (DataTable DT,stringexportfilename) {StringWriter SW=getstringwriter (DT); //Current EncodingHttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding ("GB2312"); //encode the file name of the output            stringFileName =Httputility.urlencode (Exportfilename, System.Text.Encoding.UTF8); //file name            stringstr ="attachment;filename="+ FileName +". xls"; //put the file header output, this file header activates the file download boxHttpContext.Current.Response.AppendHeader ("content-disposition", str);//HTTP header FileHttpContext.Current.Response.ContentType ="Application/ms-excel";  This. Page.enableviewstate =false;            Response.Write (SW);        Response.End (); }  

2. Call

            string " ";             = Dbhelpersql.query (SQL). tables[0];             if 0 )            {                // export Excel                  excelimport (DT, DateTime.Now.ToString ( ));            }