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("");
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("")
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", "");
}
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", "")
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
