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Display Images from Database in Gridview in Asp.net using Handler (ashx) File in C#, VB.NET

Jul 14, 2015
Introduction

Here I will explain how to show or display binary format images from database in gridview in asp.net using handler ashx file
 using c#, vb.net with example or upload images in binary format and displaying images from sql server database using handler ashx in asp.net gridview using c#, vb.net.


Before implement this example first design one table imagedetails in your database as shown below

Column Name
Data Type
Allow Nulls
imageid
Int(IDENTITY=TRUE)
NO
imagename
varchar(50)
Yes
imagedata
varbinary(max)
Yes
Once table created in database that would be like as shown below


Now open your aspx page and write the code like as shown below


<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1">
<title>Display images from sql server database in asp.net gridview control</title>
<style type="text/css">
.GridviewDiv {font-size: 100%; font-family: 'Lucida Grande', 'Lucida Sans Unicode', Verdana, Arial, Helevetica, sans-serif; color: #303933;}
.headerstyle
{
color:#FFFFFF;border-right-color:#abb079;border-bottom-color:#abb079;background-color: #df5015;padding:0.5em 0.5em 0.5em 0.5em;text-align:center;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:FileUpload ID="fileUpload1" runat="server" /><br />
<asp:Button ID="btnUpload" runat="server" Text="Upload" onclick="btnUpload_Click" />
</div>
<div class="GridviewDiv">
<asp:GridView ID="gvImages" CssClass="Gridview" runat="server" AutoGenerateColumns="False">
<HeaderStyle CssClass="headerstyle" />
<Columns>
<asp:BoundField HeaderText = "Image Name" DataField="imagename" />
<asp:TemplateField HeaderText="Image">
<ItemTemplate>
<asp:Image ID="Image1" runat="server" ImageUrl='<%# "ImageHandler.ashx?ImID="+ Eval("imageid") %>' Height="150px" Width="150px"/>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
</div>
</form>
</body>
</html>

Now add following namespaces in codebehind file

C# Code


using System;
using System.Data.SqlClient;
using System.IO;
using System.Web.UI.WebControls;
using System.Web;

After completion of adding namespaces you need to write the code like as shown below


string strCon = "Data Source=Suresh;Integrated Security=true;Initial Catalog=MySampleDB";
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindGridviewData();
}
}
// Bind Gridview Data
private void BindGridviewData()
{
using (SqlConnection con = new SqlConnection(strCon))
{
using (SqlCommand cmd = new SqlCommand())
{
cmd.CommandText = "select imageid,imagename from imagedetails";
cmd.Connection = con;
con.Open();
gvImages.DataSource = cmd.ExecuteReader();
gvImages.DataBind();
con.Close();
}
}
}
// Save files to Folder and files path in database
protected void btnUpload_Click(object sender, EventArgs e)
{
//Condition to check if the file uploaded or not
if (fileUpload1.HasFile)
{
int length = fileUpload1.PostedFile.ContentLength;
byte[] imgbyte = new byte[length];
HttpPostedFile img = fileUpload1.PostedFile;
//set the binary data
img.InputStream.Read(imgbyte, 0, length); 
string filename = Path.GetFileName(fileUpload1.PostedFile.FileName);
using (SqlConnection con = new SqlConnection(strCon))
{
using (SqlCommand cmd = new SqlCommand())
{
cmd.CommandText = "insert into imagedetails(imagename,imagedata) values(@Name,@Data)";
cmd.Parameters.AddWithValue("@Name", filename);
cmd.Parameters.AddWithValue("@Data", imgbyte);
cmd.Connection = con;
con.Open();
cmd.ExecuteNonQuery();
con.Close();
BindGridviewData();
}
}
}
}

VB.NET Code


Imports System.Data.SqlClient
Imports System.IO
Imports System.Web.UI.WebControls
Imports System.Web
Partial Class VBCode
Inherits System.Web.UI.Page
Private strCon As String = "Data Source=Suresh;Integrated Security=true;Initial Catalog=MySampleDB"
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
If Not IsPostBack Then
BindGridviewData()
End If
End Sub
' Bind Gridview Data
Private Sub BindGridviewData()
Using con As New SqlConnection(strCon)
Using cmd As New SqlCommand()
cmd.CommandText = "select imageid,imagename from imagedetails"
cmd.Connection = con
con.Open()
gvImages.DataSource = cmd.ExecuteReader()
gvImages.DataBind()
con.Close()
End Using
End Using
End Sub
' Save files to Folder and files path in database
Protected Sub btnUpload_Click(ByVal sender As Object, ByVal e As EventArgs)
'Condition to check if the file uploaded or not
If fileUpload1.HasFile Then
Dim length As Integer = fileUpload1.PostedFile.ContentLength
Dim imgbyte As Byte() = New Byte(length - 1) {}
Dim img As HttpPostedFile = fileUpload1.PostedFile
'set the binary data
img.InputStream.Read(imgbyte, 0, length)
Dim filename As String = Path.GetFileName(fileUpload1.PostedFile.FileName) 
Using con As New SqlConnection(strCon)
Using cmd As New SqlCommand()
cmd.CommandText = "insert into imagedetails(imagename,imagedata) values(@Name,@Data)"
cmd.Parameters.AddWithValue("@Name", filename)
cmd.Parameters.AddWithValue("@Data", imgbyte)
cmd.Connection = con
con.Open()
cmd.ExecuteNonQuery()
con.Close()
BindGridviewData()
End Using
End Using
End If
End Sub
End Class

If you observe above gridview TemplateField code in aspx page we are fetching images using Handler file ImageHandler.ashx because we are saving images in binary format. By using HTTPHandler we can easily get binary data and display it in our application.

Here HTTPHandler is a simple class that allows you to process a request and return a response to the browser. Simply we can say that a Handler is responsible for fulfilling requests from the browser. It can handle only one request at a time, which in turn gives high performance.
To add handler file Right Click on your project à select Add New Item à select Handler file à give name as ImageHandler.ashx like as shown in following image and click ok

Now open your ImageHandler.ashx file and write the following code

C# Code


using System;
using System.Web;
using System.Data.SqlClient;
public class ImageHandler : IHttpHandler {
public void ProcessRequest (HttpContext context) {
string imageid = context.Request.QueryString["ImID"];
SqlConnection con = new SqlConnection("Data Source=Suresh;Integrated Security=true;Initial Catalog=MySampleDB");
con.Open();
SqlCommand cmd = new SqlCommand("select imagedata from imagedetails where imageid=" + imageid, con);
SqlDataReader dr = cmd.ExecuteReader();
dr.Read();
context.Response.BinaryWrite((byte[])dr[0]);
con.Close();
context.Response.End();
}
public bool IsReusable {
get {
return false;
}
}
}

VB.NET Code


Imports System.Web
Imports System.Data.SqlClient
Public Class Handler : Implements IHttpHandler
Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
Dim imageid As String = context.Request.QueryString("ImID")
Dim con As New SqlConnection("Data Source=Suresh;Integrated Security=true;Initial Catalog=MySampleDB")
con.Open()
Dim cmd As New SqlCommand(Convert.ToString("select imagedata from imagedetails where imageid=") & imageid, con)
Dim dr As SqlDataReader = cmd.ExecuteReader()
dr.Read()
context.Response.BinaryWrite(DirectCast(dr(0), Byte()))
con.Close()
context.Response.[End]()
End Sub
Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
Get
Return False
End Get
End Property
End Class

Now run your application and check output that would be like as shown in following output

Demo

Display Images from Database in Gridview in Asp.net using Handler (ashx) File in C#, VB.NET

Download Sample Code Attached


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