Better solution ?

[LB]

Hello everybody,
I'm trying to display into a system.Web.UI.WebControls.Image a picture
coming from the DB.
I used the code below, and after specifying my image1.url property, the
image is displayed.

But now, I have still the image stored in my "DestFilePath " directory.
Is there a way to directly read the blob, and assign it to my
system.Web.UI.WebControls.Image without writing the file itself to the disk
?

Thank you so much in advance
LB


Public Sub GetBlobInfo(DestFilePath As String)
Try
Dim PictureCol As Integer = 0 ' the column # of the BLOB field
Dim cn As New SqlConnection("server=localhost;integrated
security=yes;database=SomeDB")
Dim cmd As New SqlCommand("SELECT Picture FROM mytable WHERE
somecondition='Test'", cn)
cn.Open()
Dim dr As SqlDataReader = cmd.ExecuteReader()
dr.Read()
Dim b(dr.GetBytes(PictureCol, 0, Nothing, 0, Integer.MaxValue)) As
[Byte]
dr.GetBytes(PictureCol, 0, b, 0, b.Length)
dr.Close()
cn.Close()
Dim fs As New System.IO.FileStream(DestFilePath,
System.IO.FileMode.Create, System.IO.FileAccess.Write)

fs.Write(b, 0, b.Length)
fs.Close()
MessageBox.Show("Image written to file successfully")
Catch ex As SqlException
MessageBox.Show(ex.Message)
End Try
End Sub

 

[Eliyahu Goldin]

The standard solution is to a have a special web page, called, for example,
GetImage.aspx. Your image url will point to the page:

ImageUrl="GetImage.aspx?id=myImageId"

The page will find the image in the database according to id and stream it
down to the client in the response stream.

Eliyahu

 

[Kevin Spencer]

Sure. You fetch it from the db, convert the array of bytes to a stream, sets
the Response.ContentType to "image/jpg", and save the stream to the
Response.OutputStream. This can be done by creating an ASPX page that serves
as the "image url."

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
What You Seek Is What You Get.

 

[Joseph Byrns]

So just to add to what the other two said, here is an example, this is the
load event of a page called GetImage.aspx:

Response.Cache.SetCacheability(HttpCacheability.NoCache)
Response.Clear()
Response.ContentType = "image/jpg"
Dim map As Bitmap = CType(Session("map"), Bitmap) ''you would get the image
from the db here
Dim ms As New MemoryStream
map.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg)
Response.BinaryWrite(ms.ToArray)
Response.End()

Sure. You fetch it from the db, convert the array of bytes to a stream,
sets the Response.ContentType to "image/jpg", and save the stream to the
Response.OutputStream. This can be done by creating an ASPX page that
serves as the "image url."

--
HTH,

Kevin Spencer
Microsoft MVP
.Net Developer
What You Seek Is What You Get.

Hello everybody,
I'm trying to display into a system.Web.UI.WebControls.Image a picture
coming from the DB.
I used the code below, and after specifying my image1.url property, the
image is displayed.

But now, I have still the image stored in my "DestFilePath " directory.
Is there a way to directly read the blob, and assign it to my
system.Web.UI.WebControls.Image without writing the file itself to the
disk ?

Thank you so much in advance
LB


Public Sub GetBlobInfo(DestFilePath As String)
Try
Dim PictureCol As Integer = 0 ' the column # of the BLOB field
Dim cn As New SqlConnection("server=localhost;integrated
security=yes;database=SomeDB")
Dim cmd As New SqlCommand("SELECT Picture FROM mytable WHERE
somecondition='Test'", cn)
cn.Open()
Dim dr As SqlDataReader = cmd.ExecuteReader()
dr.Read()
Dim b(dr.GetBytes(PictureCol, 0, Nothing, 0, Integer.MaxValue)) As
[Byte]
dr.GetBytes(PictureCol, 0, b, 0, b.Length)
dr.Close()
cn.Close()
Dim fs As New System.IO.FileStream(DestFilePath,
System.IO.FileMode.Create, System.IO.FileAccess.Write)

fs.Write(b, 0, b.Length)
fs.Close()
MessageBox.Show("Image written to file successfully")
Catch ex As SqlException
MessageBox.Show(ex.Message)
End Try
End Sub

 

[Brock Allen]

Here's a sample that does something very similar:

http://staff.develop.com/ballen/blog/PermaLink.aspx?guid=2d8b430b-8361-416d-9df8-9aff48bf2481

-Brock
DevelopMentor
http://staff.develop.com/ballen