How to Print in ASP.NET 2.0

One of the most common functionality in any ASP.NET application is to print forms and controls.
There are a lot of options to print forms using client scripts. In the article, we will see how
to print controls in ASP.NET 2.0 using both server side code and javascript.

Step 1: Create a PrintHelper class. This class contains a method called PrintWebControl that
can print any control like a GridView, DataGrid, Panel, TextBox etc. The class makes a call to
window.print() that simulates the print button.

Note: I have not written this class and neither do I know the original author. I will be happy
to add a reference in case someone knows. 

C# 

using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.IO;

using System.Text;

using System.Web.SessionState;

public class PrintHelper

{

    public PrintHelper()

    {

    }

    public static void PrintWebControl(Control ctrl)

    {

        PrintWebControl(ctrl, string.Empty);

    }

    public static void PrintWebControl(Control ctrl, string Script)

    {

        StringWriter stringWrite = new StringWriter();

        System.Web.UI.HtmlTextWriter htmlWrite =
                new System.Web.UI.HtmlTextWriter(stringWrite);

        if (ctrl is WebControl)

        {

            Unit w = new Unit(100, UnitType.Percentage);
            ((WebControl)ctrl).Width = w;

        }

        Page pg = new Page();

        pg.EnableEventValidation = false;

        if (Script != string.Empty)

        {

            pg.ClientScript.RegisterStartupScript(pg.GetType(),
                                         "PrintJavaScript", Script);

        }

        HtmlForm frm = new HtmlForm();

        pg.Controls.Add(frm);

        frm.Attributes.Add("runat", "server");

        frm.Controls.Add(ctrl);

        pg.DesignerInitialize();

        pg.RenderControl(htmlWrite);

        string strHTML = stringWrite.ToString();

        HttpContext.Current.Response.Clear();

        HttpContext.Current.Response.Write(strHTML);

        HttpContext.Current.Response.Write("<script>window.
                                             print();</script>");

        HttpContext.Current.Response.End();

    }

}

VB.NET

Imports System

Imports System.Data

Imports System.Configuration

Imports System.Web

Imports System.Web.Security

Imports System.Web.UI

Imports System.Web.UI.WebControls

Imports System.Web.UI.WebControls.WebParts

Imports System.Web.UI.HtmlControls

Imports System.IO

Imports System.Text

Imports System.Web.SessionState

Public Class PrintHelper

    Public Sub New()

    End Sub

    Public Shared Sub PrintWebControl(ByVal ctrl As Control)

        PrintWebControl(ctrl, String.Empty)

    End Sub

    Public Shared Sub PrintWebControl(ByVal ctrl As Control,
                                           ByVal Script As String)

        Dim stringWrite As StringWriter = New StringWriter()

        Dim htmlWrite As System.Web.UI.HtmlTextWriter =
                    New System.Web.UI.HtmlTextWriter(stringWrite)

        If TypeOf ctrl Is WebControl Then

            Dim w As Unit = New Unit(100, UnitType.Percentage)

            CType(ctrl, WebControl).Width = w

        End If

        Dim pg As Page = New Page()

        pg.EnableEventValidation = False

        If Script <> String.Empty Then

            pg.ClientScript.RegisterStartupScript(pg.GetType(),
            "PrintJavaScript", Script)

        End If

        Dim frm As HtmlForm = New HtmlForm()

        pg.Controls.Add(frm)

        frm.Attributes.Add("runat", "server")

        frm.Controls.Add(ctrl)

        pg.DesignerInitialize()

        pg.RenderControl(htmlWrite)

        Dim strHTML As String = stringWrite.ToString()

        HttpContext.Current.Response.Clear()

        HttpContext.Current.Response.Write(strHTML)

        HttpContext.Current.Response.Write("<script>window.print();
                                                        </script>")

        HttpContext.Current.Response.End()

    End Sub

End Class

Step 2: Create two pages, Default.aspx and Print.aspx. Default.aspx will
contain the controls to be printed. Print.aspx will act as a popup page to
invoke the print functionality.

Step 3: In your Default.aspx, drag and drop a few controls that you
would like to print. To print a group of controls, place them all in a
container control like a panel. This way if we print the panel using our
PrintHelper class, all the controls inside the panel gets printed.

Step 4: Add a print button to the Default.aspx and in the code behind,
type the following code:

C#

protected void btnPrint_Click(object sender, EventArgs e)

    {

        Session["ctrl"] = Panel1;

        ClientScript.RegisterStartupScript(this.GetType(),
        "onclick", "<script language=javascript>window.open
                  ('Print.aspx','PrintMe','height=300px,width=300px,
                         scrollbars=1');/script>");

    }                

VB.NET

Protected Sub btnPrint_Click(ByVal sender As Object, ByVal e As
                               System.EventArgs) Handles btnPrint.Click

        Session("ctrl") = Panel1

        ClientScript.RegisterStartupScript(Me.GetType(), "onclick",
        "<script language=javascript>window.open    ('Print.aspx',
                              'PrintMe','height=300px,width=300px,
                                             scrollbars=1');</script>")

End Sub

The code stores the control in a Session variable to be accessed in the pop up page,
Print.aspx. If you want to print directly on button click, call the Print functionality in
the following manner :

PrintHelper.PrintWebControl(Panel1);

Step 5: In the Page_Load event of Print.aspx.cs, add the following code:

C#

protected void Page_Load(object sender, EventArgs e)

    {

        Control ctrl = (Control)Session["ctrl"];

        PrintHelper.PrintWebControl(ctrl);

    }

VB.NET

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
                                                             Handles Me.Load

        Dim ctrl As Control = CType(Session("ctrl"), Control)

        PrintHelper.PrintWebControl(ctrl)

End Sub

Well that's it. Try out the sample attached with this article and print any control you desire.