CODEWITHSUNDEEP
c#asp.netlistview
cptully
cptully

Reputation: 697

<asp:ListView DeleteMethod > not updating UI

I an building a webforms page and making a lot of progress with web searches and help from the Stack Overflow community, but I have hit another snag that is likely due to my own inexperience.

Here is my ListView opening tag:

                <asp:ListView ID="lvLeadershipPositions"
                DataKeyNames="ID"
                InsertItemPosition="LastItem"
                runat="server" 
                ItemType="BusinessLogic.Alumni.Outreach.ServicePosition"
                SelectMethod="lvLeadershipPositions_GetData"
                InsertMethod="lvLeadershipPositions_InsertItem"
                UpdateMethod="lvLeadershipPositions_UpdateItem"
                DeleteMethod="lvLeadershipPositions_DeleteItem">

and here is the code behind for the SelectMethod, InsertMethod, UpdateMethod and DeleteMethod:

    public IEnumerable<ServicePosition> lvLeadershipPositions_GetData()
    {
        if (alumn == null)
        {
            alumn = new Alumn();
        }

        return alumn.LeadershipRoles;
    }

    public void lvLeadershipPositions_InsertItem()
    {
        var item = new BusinessLogic.Alumni.Outreach.ServicePosition();
        TryUpdateModel(item);
        if (ModelState.IsValid)
        {
            // Save changes here
            item.ID = alumn.LeadershipRoles.Count;
            alumn.LeadershipRoles.Add(item);
        }
    }

    // The id parameter name should match the DataKeyNames value set on the control
    public void lvLeadershipPositions_UpdateItem(int id)
    {
        ServicePosition item = alumn.LeadershipRoles.Find(x => x.ID == id);
        // Load the item here, e.g. item = MyDataLayer.Find(id);
        if (item == null)
        {
            // The item wasn't found
            ModelState.AddModelError("", String.Format("Item with id {0} was not found", id));
            return;
        }
        TryUpdateModel(item);
        if (ModelState.IsValid)
        {
            // Save changes here, e.g. MyDataLayer.SaveChanges();

        }
    }

    // The id parameter name should match the DataKeyNames value set on the control
    public void lvLeadershipPositions_DeleteItem(int id)
    {
        int count = alumn.LeadershipRoles.Count(x => x.ID == id);
        if (count == 1)
        {
            int removeID = alumn.LeadershipRoles.Where(x => x.ID == id).First().ID;
            alumn.LeadershipRoles.RemoveAt(removeID);
            return;
        }
        else if (count == 0)
        {
            ModelState.AddModelError("", String.Format("Item with id {0} was not found", id));
            return;
        }
        else
        {
            ModelState.AddModelError("", String.Format("More than one Item with id {0} was found", id));
        }
    }

The first three methods all do exactly what I expect. For example, when clicking the update button on my page, the lvLeadershipPositions_UpdateItem method is called, and then the lvLeadershipPositions_GetData method is called.

And when I click the delete button lvLeadershipPositions_DeleteItem is called but lvLeadershipPositions_GetData is never called, so the page does not update to reflect my deletion.

What have I left out?

Upvotes: 1

Views: 100

Answers (1)

Giox
Giox

Reputation: 5123

I think you have removed the item from the data source but you haven't rebound the list view.

Force a rebind with lvLeadershipPositions.DataBind() or call your method TryUpdateModel(item) where maybe there is the DataBind call.

Upvotes: 1

Related Questions