Custom ListView to show EmptyDataTemplate and InsertItemTemplate at the same time

Question

It is known that the ListView control can't display both an EmptyDataTemplate and a InsertItemTemplate at the same time.

For my design style I need to be able to show both. I want to be able to show that no data exist and at the same time show a form to add new data.

I've already implemented various solutions, such as putting a PlaceHolder in my LayoutTemplate and then manually showing or hiding this PlaceHolder in the code-behind, depending on if there is data or not.

However, I would like a control that has this built-in capability in order to keep my code-behind light.

I believe there are only two ways to achieve what I want:

1. First way (preferred) is to write that custom control myself. I was thinking of deriving from ListView and overriding the function responsible for disabling the EmptyDataTemplate, but I have no experience with custom controls. And I'm not even sure it will work in the end.

2. Second way is to use a custom control found or purchased somewhere. I have not been able to find such control that has the same base capabilities as the ListView.

Has anybody any idea how to solve #1 and maybe #2?

Thank you.

Answer 1

I don't understand much of your requirement without a screen shot of what you are actually trying to achieve. Anyway, you may be able to achieve this interface with a combination of ListView+FormView or ListView+ a User Control. If you can provide any more info I may help further.

Answer 2

I would go for your option 1: Create a custom control Because you haven't specified a programming language I made one in VB.NET:

Public Class CustomListView
    Inherits ListView
    Public Sub CheckEmptyData() Handles Me.PreRender
        If Me.Items.Count = 0 Then
            Dim label As New Label
            label.Text = "No data found <br/>"
            Me.Controls.AddAt(0, label)
        End If
    End Sub
End Class

Just tested it and works perfectly, it can just replace an existing ListView.

As you can see it checks if there is any data and if not it inserts a label with the text "No data found". I haven't found an easy way to use the EmptyDataTemplate for this, that would be a better option but this might already work for you.

Another option is to hide the InsertItem (InsertItemPosition.None) if there is no data, and add a Button "Insert" to the EmptyDataTemplate that enables the InsertItemTemplate and therefore hides the EmptyDataTemplate.

Answer 3

Here is what I ended up doing:

public class MyListView : ListView
{
    protected override int CreateChildControls(IEnumerable dataSource, bool dataBinding)
    {
        int itemCount = base.CreateChildControls(dataSource, dataBinding);

        if (this.InsertItemPosition != InsertItemPosition.None && itemCount == 0)
        {
            CreateEmptyDataItem();
        }

        return itemCount;
    }
}

Works great!