In one of my projects, I needed to implement barcodes into an ASP.NET page. Unfortunately, the only way that I found was using a third party component. So, I decided to find a way to do it without using external components.
Using the code
First, you have to download a free barcode font. For this example, I used "IDAutomationHC39M" from IdAutomation. In this example, I used Barcode 39.
In WinForms applications, it is really easy to use Barcode fonts; just place a Label, and apply the free barcode font, and assign a value, and everything is ready.
In Webforms, things are different, because the application runs on the server. The barcode font must reside on the server. If we use a Label, the barcode font is located on the server, not on the client, so you will just see the value, not the barcode.
Well, let's start:
Just copy the barcode font into the windows\fonts folder of the server. The whole idea is to create a text with the font (a barcode), then create an image of it, and send it back to the client.
Here is a simple page with it:
'===========================================================================================
Code (C#)
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Imaging;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace Barcodes
{
/// <summary />
/// Summary description for BarCode.
/// </summary />
public class BarCode : System.Web.UI.Page
{
private void Page_Load(object sender, System.EventArgs e)
{
// Get the Requested code to be created.
string Code = Request["code"].ToString();
// Multiply the lenght of the code by 40 (just to have enough width)
int w = Code.Length * 40;
// Create a bitmap object of the width that we calculated and height of 100
Bitmap oBitmap = new Bitmap(w,100);
// then create a Graphic object for the bitmap we just created.
Graphics oGraphics = Graphics.FromImage(oBitmap);
// Now create a Font object for the Barcode Font
// (in this case the IDAutomationHC39M) of 18 point size
Font oFont = new Font("IDAutomationHC39M", 18);
// Let's create the Point and Brushes for the barcode
PointF oPoint = new PointF(2f, 2f);
SolidBrush oBrushWrite = new SolidBrush(Color.Black);
SolidBrush oBrush = new SolidBrush(Color.White);
// Now lets create the actual barcode image
// with a rectangle filled with white color
oGraphics.FillRectangle(oBrush, 0, 0, w, 100);
// We have to put prefix and sufix of an asterisk (*),
// in order to be a valid barcode
oGraphics.DrawString("*" + Code + "*", oFont, oBrushWrite, oPoint);
// Then we send the Graphics with the actual barcode
Response.ContentType = "image/jpeg" ;
oBitmap.Save (Response.OutputStream, ImageFormat.Jpeg);
}
}
}
'===============================================================
As you can see, there is a barcode with the value of 1234.
Now, let’s create a page that has an asp:Image on it:
'==============================================================
<%@ Page language="c#" Codebehind="WebForm1.aspx.cs"
AutoEventWireup="false" Inherits="BarCodes.WebForm1" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
<title>WebForm1</title>
<meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1">
<meta name="CODE_LANGUAGE" Content="C#">
<meta name="vs_defaultClientScript" content="JavaScript">
<meta name="vs_targetSchema"
content="http://schemas.microsoft.com/intellisense/ie5">
</HEAD>
<body MS_POSITIONING="GridLayout">
<form id="Form1" method="post" runat="server">
<asp:Image id="myBarCode" runat="server"></asp:Image>
</form>
</body>
'===========================================================
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace BarCodes
{
/// <summary />
/// Summary description for WebForm1.
/// </summary />
public class WebForm1 : System.Web.UI.Page
{
protected System.Web.UI.WebControls.Image myBarCode;
private void Page_Load(object sender, System.EventArgs e)
{
// Put user code to initialize the page here
myBarCode.ImageUrl = "BarCode.aspx?code=31231";
}
#region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: This call is required by the ASP.NET Web Form Designer.
//
InitializeComponent();
base.OnInit(e);
}
/// <summary />
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary />
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load);
}
#endregion
}
}
Load balance : Server 05
