Вы можете использовать следующий код, который генерирует PDF-файл в фоновом режиме, как при нажатии кнопки, а затем появляется в brwoser с SaveAs и возможностью отмены.
Warning[] warnings;
string[] streamIds;
string mimeType = string.Empty;
string encoding = string.Empty;`enter code here`
string extension = string.Empty;
DataSet dsGrpSum, dsActPlan, dsProfitDetails,
dsProfitSum, dsSumHeader, dsDetailsHeader, dsBudCom = null;
enter code here
//This is optional if you have parameter then you can add parameters as much as you want
ReportParameter[] param = new ReportParameter[5];
param[0] = new ReportParameter("Report_Parameter_0", "1st Para", true);
param[1] = new ReportParameter("Report_Parameter_1", "2nd Para", true);
param[2] = new ReportParameter("Report_Parameter_2", "3rd Para", true);
param[3] = new ReportParameter("Report_Parameter_3", "4th Para", true);
param[4] = new ReportParameter("Report_Parameter_4", "5th Para");
DataSet dsData= "Fill this dataset with your data";
ReportDataSource rdsAct = new ReportDataSource("RptActDataSet_usp_GroupAccntDetails", dsActPlan.Tables[0]);
ReportViewer viewer = new ReportViewer();
viewer.LocalReport.Refresh();
viewer.LocalReport.ReportPath = "Reports/AcctPlan.rdlc"; //This is your rdlc name.
viewer.LocalReport.SetParameters(param);
viewer.LocalReport.DataSources.Add(rdsAct); // Add datasource here
byte[] bytes = viewer.LocalReport.Render("PDF", null, out mimeType, out encoding, out extension, out streamIds, out warnings);
// byte[] bytes = viewer.LocalReport.Render("Excel", null, out mimeType, out encoding, out extension, out streamIds, out warnings);
// Now that you have all the bytes representing the PDF report, buffer it and send it to the client.
// System.Web.HttpContext.Current.Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.Buffer = true;
Response.Clear();
Response.ContentType = mimeType;
Response.AddHeader("content-disposition", "attachment; filename= filename" + "." + extension);
Response.OutputStream.Write(bytes, 0, bytes.Length); // create the file
Response.Flush(); // send it to the client to download
Response.End();