Render file from ReportViewer connected to Reporting Services

In this post I will show how you can use a report viewer control to connect to a Reporting Services server and call the Render function on the ReportViewer.
This is useful when we don't want to show the control, but we need to get the rendered report in different formats.

Step 1: download the Report viewer runtime from here.

Step 2: Install the runtime.

Step 3: Add the reference to your project. The dll should be in \Program Files (x86)\Microsoft Visual Studio 11.0\ReportViewer\Microsoft.ReportViewer.WinForms.dll

First we create a method that will return the report from the report viewer as an array of bytes.

public byte[] RenderFromServer()
{
ReportViewer rv = new ReportViewer();

// Set the processing mode for the ReportViewer to Remote
rv.ProcessingMode = ProcessingMode.Remote;

rv.ServerReport.ReportServerUrl = new Uri("Http://mypc/ReportServer);
rv.ServerReport.DisplayName = "New report.pdf";
rv.ServerReport.ReportPath = "/Reports/MyReport";

//set credentials
ReportServerCredentials rsCredentials = rv.ServerReport.ReportServerCredentials;

NetworkCredential nc = new NetworkCredential();
nc.Domain = "myDomain"; //can also be the computer name for local access
nc.UserName = "myUser";
nc.Password = "12333";

rsCredentials.NetworkCredentials = nc;

//set parameters
List<ReportParameter> paramLst = new List<ReportParameter>();
ReportParameter rp = new ReportParameter(ParamName, ParamValue);
paramLst.Add(rp);
                        rv.ServerReport.SetParameters(paramLst);

//get the bytes from the report viewer
Warning[] warnings;
string[] streamids;
string mimeType;
string encoding;
string extension;

byte[] bytes = rv.ServerReport.Render
("PDF", null, out mimeType, out encoding, out extension, out streamids, out warnings);

rv.Dispose(); //very important for memory management!!
return bytes;
}

Notice that I called the Render function with the "PDF" paramater. The full list can be found at http://msdn.microsoft.com/en-us/library/ms154606.aspx.

The possible values are:

• PDF
• CSV
• IMAGE
• PDF
• EXCEL
• WORD
• HTML 4.0
• MHTML

When exporting to MHTML and you need to embed the report in another html document, or the body of an email, you have to specify the DeviceInfo details:

<DeviceInfo>
   <HTMLFragment>True</HTMLFragment>
</DeviceInfo>

As stated in MSDN, "When a report is rendered as an HTML fragment, the content of the report is contained within a TABLE element without the use of an HTML or BODY element. You can use the HTML fragment to incorporate the report into an existing HTML document."

Link: http://technet.microsoft.com/en-us/library/ms155397.aspx

Then we can write the bytes to a file:

byte[] bytes = RenderFromServer();
File.WriteAllBytes("C:\\MyReport.pdf", bytes);

Or, make a memory stream from them:

byte[] bytes = RenderFromServer();
MemoryStream ms = new MemoryStream(bytes);
ms.Seek(0, SeekOrigin.Begin);