c# - File Download in javascript using AJAX call -

this java script code downloading file database on button click, when button clicks function calls. using ajax call have moved handler.

function downloaddocument() {     var currentuserempid = currentselecteduser;     ext.ajax.request({         url: "uploadattachment.ashx?mode=downloaddocument&employeeid=" + currentuserempid,         success: function (response) {             var data = response.responsetext;         },         failure: function (form, action) {         }     }); } 

here comes handler page, have got bytes of file byte[] buffer. problem here download not working. could't figure out problem, since iam beginner. please this, thankyou.

case "downloaddocument":              webclient web = new webclient();             try             {                 byte[] buffer;                  var query2 = @"select lld_decleration_doc (select  instance, employee_id, lld_decleration_doc, row_number() over(partition employee_id order update_date desc) latest [emanager].[dbo].[tax_benefit_declaration]) latest = 1 , employee_id = @employeeid";                  using (sqlconnection con = new sqlconnection(db.connectionstring))                 using (sqlcommand cmd = new sqlcommand(query2, con))                 {                     sqlparameter param = cmd.parameters.add("@employeeid", sqldbtype.int);                     param.value = employeeid;                     con.open();                      buffer = (byte[])cmd.executescalar();                     con.close();                 }                  httpresponse response = httpcontext.current.response;                 response.clear();                 response.clearcontent();                 response.clearheaders();                 response.buffer = true;                 response.contenttype = "application/octet-stream";                 string header = "attachment; filename=newfile";                 response.appendheader("content-disposition", header);                 context.response.binarywrite(buffer);                 response.end();             }             catch { }             break;     } 

this said many times. cant ajax call.

you can achive invoke hidden iframe example:

                var body = ext.getbody();                 var comp = body.getbyid('hiddenform-iframe-download');                 if (!ext.isempty(comp)) {                     comp.remove();                 }                 body.createchild({                     tag: 'iframe',                     cls: 'x-hidden',                     id: 'hiddenform-iframe-download',                     name: 'iframe',                     src: "yourcontexttodownload?param1="+something                 });