display/retrieve image from sql database in vb.net - database

Question

This should be pretty simple for a pro. I have images in sql server database and I want to retrieve them in my aspx (vb.net) file.
I have in aspx this image control -
in vb.net i have started this code -
Private Sub ImageDisplay()
Dim SqlCnn As SqlConnection = Nothing, sql As String = ""
ConnectDB(SqlCnn)
Try
sql = "SELECT image FROM employees (NOLOCK) WHERE ID =" & emp_id
sqlcmd = New SqlCommand(sqlstr, SqlCnn)
Dim imageData As Byte() = DirectCast(sqlcmd.ExecuteScalar(), Byte())
Dim newImage As Image = Nothing
If Not imageData Is Nothing Then
Using ms As New MemoryStream(imageData, 0, imageData.Length)
ms.Write(imageData, 0, imageData.Length)
newImage = Image.FromStream(ms, True)
End Using
image1.Image = newImage
End If
Catch ex As Exception
ReportError(ex)
Finally
CloseDB(SqlCnn)
End Try
End Sub
I am getting error on 2 places.
- newImage = Image.FromStream(ms, True)
- image1.Image = newImage
Fromstream is not a member of system.web.ui.webcontrols.image
and second error Image is not a member of system.web.ui.webcontrols.image

Answer 1

You need both a command object and a data reader. However, you are putting them in the wrong page.
If you check out the properties of the Image control you will see that it doesn't have any Image property, so you can't load an image and put in the control. The reason for that is that you can't send both the page and the image in the same response, instead the browser has to request the image separately when the page loads.
To get the image from the database and show in the web page you need a separate proxy page that you can use to get only the image data from the database. In the ImageUrl property of the Image control you would put something like "GetImage.ashx". Then you make an HTTP handler with that name that will just get the image data from the database and write to the response stream.
Example:
Private Sub HandleRequest(context as HttpContext)
Dim SqlCnn As SqlConnection = Nothing, sql As String
Dim emp_id As Integer
emp_id = Int32.Parse(context.Request.QueryString("id"))
ConnectDB(SqlCnn)
Try
sql = "SELECT image FROM employees (NOLOCK) WHERE ID =" & emp_id
sqlcmd = New SqlCommand(sqlstr, SqlCnn)
Dim imageData As Byte() = DirectCast(sqlcmd.ExecuteScalar(), Byte())
context.Response.ContentType = "image/jpeg"
context.Response.BinaryWrite(imageData)
Catch ex As Exception
ReportError(ex)
Finally
CloseDB(SqlCnn)
End Try
End Sub

Answer 2

Dim cn As SqlConnection
cn = New SqlConnection
cn.ConnectionString = "Data Source=UMAR\UMAR;Initial Catalog=DMCHS;Integrated Security=True"
Dim cmd As New System.Data.SqlClient.SqlCommand("select D1 from DBFile where mem_no=2")
cmd.Connection = cn
cmd.CommandType = CommandType.Text
Dim ImgStream As New IO.MemoryStream(CType(cmd.ExecuteScalar, Byte()))
PictureBox1.Image = Image.FromStream(ImgStream)
ImgStream.Dispose()
cmd.Connection.Close()