Solved

how to access listview value on delete command

Posted on 2014-01-29
6
500 Views
Last Modified: 2014-01-30
I would like to ask for help regarding an asp page with a list view.

I want to get the Id value for the selected row, so that I can query the entity framework, get the record and delete it.

Down below is the code for when I do the e.Command = "Delete"
        If e.CommandName = "Delete" Then

            Dim myContext As New OLTPEntities
            Dim myRecipeStepsHistory = myContext.RefineRecipeStep.Where("it.Recipe_Id=" & Me.lvRecipeSteps.FindControl("Recipe_Id").ToString())
            Dim strRefineRecipeStepRecord = New StringBuilder("")

            If Not IsNothing(myRecipeStepsHistory) Then
                ' Recipe_Id
                strRefineRecipeStepRecord.Append("Recipe_Id: " & Me.lvRecipeSteps.FindControl("Recipe_Id").ToString() & ", ")

Open in new window

I get an Object reference not set to an instance of an object, message.

Dim myRecipeStepsHistory = myContext.RefineRecipeStep.Where("it.Recipe_Id=" & Me.lvRecipeSteps.FindControl("Recipe_Id").ToString())  << this line, I thinkis because I am not looking for the right control?

I have attached a copy of my aspx code. Hopefully some one will be able to provide guidance on this problem.

Thank you much.
listview-aspx-code.txt
0
Comment
Question by:metropia
  • 3
  • 2
6 Comments
 
LVL 52

Expert Comment

by:Carl Tawn
ID: 39818149
What event are you using to do the delete? The ListView Deleting event passes a Keys collection as part of it EventArgs. That collection will include the ID of the row being deleted.
0
 

Author Comment

by:metropia
ID: 39818189
I started using:
Private Sub lvRecipeSteps_ItemCommand(sender As Object, e As ListViewCommandEventArgs) Handles lvRecipeSteps.ItemCommand

Open in new window

And then check the Command Name:
If e.CommandName = "Delete"

Open in new window

I now changed the code to use ItemDeleting event, because I have a DataKeyNames="Id"
defined, but I have not been able to figure out how to access it and then query the Entities.
Private Sub lvRecipeSteps_ItemDeleting(sender As Object, e As ListViewDeleteEventArgs) Handles lvRecipeSteps.ItemDeleting
Dim myContext As New OLTPEntities
Dim myRefineRecipeSteps = myContext.RefineRecipeStep.Where("it.Id=" & Me.lvRecipeSteps.DataKeys().ToString())   << this does not work

Open in new window

0
 

Author Comment

by:metropia
ID: 39818277
I am still not able to make it work. I hope you can offer some help.

I really need it.

Thank you
0
Master Your Team's Linux and Cloud Stack!

The average business loses $13.5M per year to ineffective training (per 1,000 employees). Keep ahead of the competition and combine in-person quality with online cost and flexibility by training with Linux Academy.

 

Author Comment

by:metropia
ID: 39818301
This is my current code and my error.

screen shot error - current
0
 
LVL 52

Assisted Solution

by:Carl Tawn
Carl Tawn earned 250 total points
ID: 39820297
You don't need to cast the data key to a textbox. Try:
Dim myRefineRecipeSteps = myContext.RefineRecipeStep.Where("it.Id=" & currentDataKey.Value).FirstOrDefault()

Open in new window

0
 
LVL 83

Accepted Solution

by:
CodeCruiser earned 250 total points
ID: 39820508
Try changing

Dim myRefineRecipeSteps = myContext.RefineRecipeStep.Where("it.Id=" & Me.lvRecipeSteps.DataKeys().ToString())


to

Dim myRefineRecipeSteps = myContext.RefineRecipeStep.Where("it.Id=" & e.Keys("ID"))
0

Featured Post

Free Tool: Site Down Detector

Helpful to verify reports of your own downtime, or to double check a downed website you are trying to access.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

A long time ago (May 2011), I have written an article showing you how to create a DLL using Visual Studio 2005 to be hosted in SQL Server 2005. That was valid at that time and it is still valid if you are still using these versions. You can still re…
The article shows the basic steps of integrating an HTML theme template into an ASP.NET MVC project
Microsoft Active Directory, the widely used IT infrastructure, is known for its high risk of credential theft. The best way to test your Active Directory’s vulnerabilities to pass-the-ticket, pass-the-hash, privilege escalation, and malware attacks …
This video shows how to use Hyena, from SystemTools Software, to bulk import 100 user accounts from an external text file. View in 1080p for best video quality.

856 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question