Introduction
After Completion of above code we need to add HTTPHandler file to our project to retrieve images from database because we save our images in binary format getting the binary format of data from database it’s easy but displaying is very difficult that’s why we will use HTTPHandler to solve this problem.
Download sample code attached
Here I will explain how insert and retrieve images from database and how to bind images to gridview using asp.net.
Description:
I
have worked on one social networking site at that time we save all the
images in to directory folder and we save image path into database at
that time I got idea to implement concept like inserting images into
database and retrieving the images from database and binding images to
gridview using asp.net for that we need follow below steps
First Design table like this in your SQL Server database and give name as Image
Column Name
|
Data Type
|
Allow Nulls
|
ImageId
|
Int(set identity property=true)
|
No
|
ImageName
|
Varchar(50)
|
Yes
|
Image
| image |
Yes
|
After that Design your aspx page like this
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Inserting images into databse and displaying images with gridview</title>
<style type="text/css">
.Gridview
{
font-family:Verdana;
font-size:10pt;
font-weight:normal;
color:black;
width:500px;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div>
<table>
<tr>
<td>
Image Name:
</td>
<td>
<asp:TextBox ID="txtImageName" runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td>
Upload Image:
</td>
<td>
<asp:FileUpload ID="fileuploadImage" runat="server" />
</td>
</tr>
<tr>
<td>
</td>
<td>
<asp:Button ID="btnUpload" runat="server" Text="Upload" onclick="btnUpload_Click" />
</td>
</tr>
</table>
</div>
<div>
<asp:GridView ID="gvImages" CssClass="Gridview" runat="server" AutoGenerateColumns="False"
HeaderStyle-BackColor="#7779AF" HeaderStyle-ForeColor="white">
<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>
|
After that add System.IO and System.Data.SqlClient namespaces and write the following code in code behind
string strcon = ConfigurationManager.AppSettings["ConnectionString"].ToString();
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindGridData();
}
}
/// <summary>
/// btnUpload_Click event is used to upload images into database
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void btnUpload_Click(object sender, EventArgs e)
{
//Condition to check if the file uploaded or not
if (fileuploadImage.HasFile)
{
//getting length of uploaded file
int length = fileuploadImage.PostedFile.ContentLength;
//create a byte array to store the binary image data
byte[] imgbyte = new byte[length];
//store the currently selected file in memeory
HttpPostedFile img = fileuploadImage.PostedFile;
//set the binary data
img.InputStream.Read(imgbyte, 0, length);
string imagename = txtImageName.Text;
//use the web.config to store the connection string
SqlConnection connection = new SqlConnection(strcon);
connection.Open();
SqlCommand cmd = new SqlCommand("INSERT INTO Image (ImageName,Image) VALUES (@imagename,@imagedata)", connection);
cmd.Parameters.Add("@imagename", SqlDbType.VarChar, 50).Value = imagename;
cmd.Parameters.Add("@imagedata", SqlDbType.Image).Value = imgbyte;
int count = cmd.ExecuteNonQuery();
connection.Close();
if (count == 1)
{
BindGridData();
txtImageName.Text = string.Empty;
ScriptManager.RegisterStartupScript(this, this.GetType(), "alertmessage", "javascript:alert('" + imagename + " image inserted successfully')", true);
}
}
}
/// <summary>
/// function is used to bind gridview
/// </summary>
private void BindGridData()
{
SqlConnection connection = new SqlConnection(strcon);
SqlCommand command = new SqlCommand("SELECT imagename,ImageID from [Image]", connection);
SqlDataAdapter daimages = new SqlDataAdapter(command);
DataTable dt = new DataTable();
daimages.Fill(dt);
gvImages.DataSource = dt;
gvImages.DataBind();
gvImages.Attributes.Add("bordercolor", "black");
}
|
Here we need to restrict user to upload only image formats in file upload control for that validaiton check this post how to validate file type in file upload control using javascript
After Completion of above code we need to add HTTPHandler file to our project to retrieve images from database because we save our images in binary format getting the binary format of data from database it’s easy but displaying is very difficult that’s why we will use HTTPHandler to solve this problem.
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.
Right
Click on your project add new HTTPHandler.ashx file and give name as
ImageHandler.ashx and write the following code in pagerequest method
like this
string strcon = ConfigurationManager.AppSettings["ConnectionString"].ToString();
public void ProcessRequest(HttpContext context)
{
string imageid = context.Request.QueryString["ImID"];
SqlConnection connection = new SqlConnection(strcon);
connection.Open();
SqlCommand command = new SqlCommand("select Image from Image where ImageID=" + imageid, connection);
SqlDataReader dr = command.ExecuteReader();
dr.Read();
context.Response.BinaryWrite((Byte[])dr[0]);
connection.Close();
context.Response.End();
}
|
Demo
 |
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