Question

Scenario:

I have a web page with multiple charts and I have an ‘Export to PDF’ button that the User should be able to click and it generates a PDF that the User can then save.

Given:

A Telerik RadChart that can save itself into a memory stream as such:

MemoryStream chartStream = new MemoryStream();
RadChart1.Save(chartStream, ImageFormat.Png);

Using this memory stream, is it possible to build a PDF using the SQL Reporting Services WITH OUT saving it to a file first OR having to insert it into an MSSQL table first?

I will up-vote and/or accept any answer that is an open source or free solution to this problem as well.

Thanks.

Answer 1

Alright, just figured this out. There are three elements to this answer, two screenshots to follow in order and then some code:

1. Creating a typed dataset to hold the chart image(s)

   

2. Hooking the typed dataset up to the RDLC report

   

3. The button click code for generating the PDF and streaming it to the browser.

   protected void btnPDF_Click(object sender, EventArgs e)
   {
       //Put the image you want to display in a MemoryStream.  You can read an image from the file system
       //or generate an image, etc.  This example renders an image to a memory stream using a custom charting control.
       MemoryStream chtLoginsByMonthStream = new MemoryStream();
       this.chtLoginsByMonth.Save(chtLoginsByMonthStream, ImageFormat.Png);
   
   
       //Setup the datatable you will pass into the RDLC
       dsStudentUsage.dtUsageChartsDataTable dt = new dsStudentUsage.dtUsageChartsDataTable();
       dsStudentUsage.dtUsageChartsRow dr = dt.NewdtUsageChartsRow();
   
       //create new Byte Array, this will hold the image data from the memory stream
       byte[] chtLoginsByMonthArray = new byte[chtLoginsByMonthStream.Length];
   
       //Set pointer to the beginning of the stream
       chtLoginsByMonthStream.Position = 0;
   
       //Read the entire stream
       chtLoginsByMonthStream.Read(chtLoginsByMonthArray, 0, (int)chtLoginsByMonthStream.Length);
   
       //Put the byte array into the new datarow in the appropriate column
       dr["imgLoginsByMonth"] = chtLoginsByMonthArray;
       dt.Rows.Add(dr);
   
       //Add the data source to the report.
       ReportViewer1.LocalReport.DataSources.Add(new ReportDataSource("dsStudentUsage_dtUsageCharts", dt));
   
       //Setup objects for streaming the PDF to the browser
       Warning[] warnings;
       string[] streamids;
       string mimeType;
       string encoding;
       string extension;
       byte[] bytes;
   
   
       //Make a container for all of your report parameters
       var rptList = new List<KeyValuePair<string, string>>();
       rptList.Add(new KeyValuePair<string, string>("rpTotalLogins", "2,000"));
       //more parameters go here
   
       //Feed the report parameters into the actual "ReportParameters" class
       ReportParameter[] rptParams = new ReportParameter[rptList.Count];
       for (int i = 0; i < rptList.Count; i++)
       {
           rptParams[i] = new ReportParameter(rptList[i].Key, rptList[i].Value);
       }
   
       //Set parameters for the report.
       ReportViewer1.LocalReport.SetParameters(rptParams);
   
       //Render the report to a byte array in PDF format
       bytes = ReportViewer1.LocalReport.Render("PDF", null, out mimeType, out encoding, out extension, out streamids, out warnings);
   
       //Set the stream to either prompt user as file download or "inline" to stream
       //PDF directly into the browser window.
   
       HttpContext.Current.Response.AddHeader("Content-disposition", "attachment; filename=StudentUsageReport.pdf");
       //HttpContext.Current.Response.AddHeader("Content-disposition", "inline;");
       HttpContext.Current.Response.ContentType = "application/pdf";
       HttpContext.Current.Response.BinaryWrite(bytes);
       HttpContext.Current.Response.End();
   
   }