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Open File in Correct Application - .NET / Blob / Oracle / Datagrid

I was wondering if someone an help me get this solution.

I insert a blob into our oracle 9i database. That's fine, no problems with the insert. Now I want to return the information (file name and blob) and place it into a datagrid. All I want though is for the user to see a list of file names and they can click on a file name and it will open the file up in the correct application (word, excel etc...)

Here is some of what I have. This code is what I'm using to manipulate the datagrid, but it's really wrong. I'm returning two field names from my stored procedure: cmnt_txt (name of the blob file) and the actual blob file.

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Private Sub dgappln_attm_ItemDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DataGridItemEventArgs) Handles dgappln_attm.ItemDataBound
If e.Item.ItemType = ListItemType.Item Or e.Item.ItemType = ListItemType.AlternatingItem Then
Dim HLAttachment As HyperLink = e.Item.Cells(0).FindControl("HLAttachment")
HLAttachment.NavigateUrl = e.Item.DataItem("cmnt_txt") 'not right. I want it to open not navigate to a url
HLAttachment.Text = e.Item.DataItem("cmnt_txt").ToString 'this is the list of file names

End If
End Sub

********************************************

I'll award extra points for quick response and easy to implement. Please be gentle, I'm a beginner and get lost easy. :)
Thanks! ;)

ASKER CERTIFIED SOLUTION

gregoryyoung

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culshaja

You need to use a hyperlink rather than a a linkbutton for the link to open the file in the datagrid. You then need to implement a HTTPModule. The following is an example:

Public Class DocumentRequestHandler
Implements IHttpHandler

'Notice ProcessRequest is the only method
'exposed by the IHttpHandler
Public Sub ProcessRequest(ByVal context As HttpContext) Implements System.Web.IHttpHandler.ProcessRequest
Dim strFilename As String

Dim appsrv As New WebService.ASMXFile
'grab filename from end of URL
Dim strArray As String() = Split(context.Request.RawUrl, "/")

strFilename = strArray(UBound(strArray))
strArray.Initialize()
strArray = Split(strFilename, ".")
strFilename = strArray(0)
strArray = Nothing

context.Response.ContentType = "application/pdf"
context.Response.BinaryWrite(appsrv.GetDocumentBinary(strFilename))

End Sub

'By calling IsReusable, an HTTP factory can query a handler to
'determine whether the same instance can be used to service
'multiple requests

Public ReadOnly Property IsReusable() As Boolean Implements System.Web.IHttpHandler.IsReusable
Get
Return True
End Get
End Property

End Class

The ContentType will need to be set with the correct MIMEType based on the file extension of the file. You can simply do that with a case statement.

You need to andd the following to the <HTTPHandlers> section of Web.config:

<add verb="*" path="*xdocuments/*" type="YourProjectName.DocumentRequestHandler, YourProjectName"/>

The url of the document needs to have xdocuments/filenamefromdb for this to work as the HTTPHandler is only invoked to pull the document from the database when it sees xdocuments in the URL.

James :-)

gregoryyoung

oh whoops didnt see that it was asp.net. actually all you need to do is set the content type and the write the binary to response.

ill post an example when I get to the office in about 45 minutes.

numten

ASKER

I would greatly appreciate that! :) Thanks!

numten

ASKER

I haven't had a chance to try out your suggestion, but I will tomorrow. I did not forget about you and your hard work!

gregoryyoung

put something along the lines of this in the page load of "File.aspx"

//get the image id from the url
string ImageId = Request.QueryString["FileId"];

//build our query statement
string sqlText = "SELECT data, contenttype FROM files WHERE pkFileId = " + FileId;

SqlConnection connection = new SqlConnection(ConenctionString);
SqlCommand command = new SqlCommand( sqlText, connection);

//open the database and get a datareader
connection.Open();
SqlDataReader dr = command.ExecuteReader();
if ( dr.Read()) //yup we found our image
{
Response.ContentType = dr["contenttype"].ToString();
Response.BinaryWrite( (byte[]) dr["data"] );
}
connection.Close();

then you can put your links to "file.aspx?FileId=5" (or whatever)

You can do this most of the time with your response (just change the content type). If the remote pc knows the content type it can open.