Display a list of images in a gridview from SQL - asp.net

Question

Using VS2013 (asp.net, VB) and SQL Server 2012.
I have a table in my database that consists of columns ID, Name and ProfilePic. ProfilePic has a type of image.
I want to display a list of ALL of the images in a gridview. Looking at google I can only find examples where someone is selecting an image based on an ID which is not what I want.
Here is my imageHandler.ashx:
<%# WebHandler Language="VB" Class="profilePICHandler" %>
Imports System
Imports System.Web
Imports System.Data.SqlClient
Public Class profilePICHandler : Implements IHttpHandler
Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
Dim con As New SqlConnection()
con.ConnectionString = ConfigurationManager.ConnectionStrings("nefsaConnectionString").ConnectionString
' Create SQL Command
Dim cmd As New SqlCommand()
cmd.CommandText = "select * from ProfilePics"
cmd.CommandType = System.Data.CommandType.Text
cmd.Connection = con
con.Open()
Dim dReader As SqlDataReader = cmd.ExecuteReader()
dReader.Read()
context.Response.BinaryWrite(DirectCast(dReader("profilepic"), Byte()))
dReader.Close()
con.Close()
End Sub
Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
Get
Return False
End Get
End Property
End Class
On my aspx page I have this
<asp:GridView ID="gridSelectAPic" runat="server"
AutoGenerateColumns="false">
<Columns>
<asp:TemplateField HeaderText="Image">
<ItemTemplate>
<asp:Image runat="server"
ImageUrl='<%# "ProfilePICHandler.ashx"%>'
ID="profilePIC" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
And on the code behind I have this
Dim dt As New DataTable
Dim conn As New SqlConnection(ConnectionString)
Using conn
Dim ad As New SqlDataAdapter("Select * from ProfilePics", conn)
ad.Fill(dt)
End Using
gridSelectAPic.DataSource = dt
gridSelectAPic.DataBind()
I am at a bit of a loss how to proceed so any help greatly appreciated

Answer 1

Its because your handler is implemented wrong. You will need a querystring to tell the handler which image you have to retrieve.
You can use asp:ImageField for brevity and readability. Markup
<asp:ImageField HeaderText="Image"
DataImageUrlField="EmployeeID"
DataImageUrlFormatString="ProfilePICHandler.ashx?id={0}" />
<asp:TemplateField HeaderText="Image">
<ItemTemplate>
<asp:Image runat="server"
ImageUrl='<%# Eval("EmployeeID", "ProfilePICHandler.ashx?id={0}")%>'
ID="profilePIC" />
</ItemTemplate>
</asp:TemplateField>
Now fetch from querystring from the generic handler like this
Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
Dim con As New SqlConnection()
con.ConnectionString = ConfigurationManager.ConnectionStrings("nefsaConnectionString").ConnectionString
Dim cmd As New SqlCommand()
cmd.CommandText = String.Format("select profilepic from ProfilePics where EmployeeID=", context.Request.QueryString("id"))
cmd.CommandType = System.Data.CommandType.Text
cmd.Connection = con
con.Open()
Dim dReader As SqlDataReader = cmd.ExecuteReader()
dReader.Read()
context.Response.BinaryWrite(DirectCast(dReader("profilepic"), Byte()))
dReader.Close()
con.Close()
End Sub
Please note that
I have given the name EmployeeID for your PK in DB
Your handler name is Pascalcased on Eval and CamelCased at its implementation. Is it a typo?
Haven't parameterized the query for brevity.