I'm using ES 2008.1.623.0 with ASP.NET 3.5.

I don't understand what I'm doing wrong. In the following code I use a ListView with esDataSource

<asp:ListView ID="ListView1" DataSourceID="esdTest" runat="server">
            <LayoutTemplate>
                <div>
                    <asp:PlaceHolder ID="itemPlaceholder" runat="server"></asp:PlaceHolder>
                </div>
            </LayoutTemplate>
            <ItemTemplate>
                <%# Eval("HotelName") %><br />
            </ItemTemplate>
</asp:ListView>
<cc1:esDataSource ID="esdTest" runat="server" />


Private Sub esdTest_esSelect(ByVal sender As Object, ByVal e As EntitySpaces.Web.esDataSourceSelectEventArgs) Handles esdTest.esSelect

        Dim coll As New HotelViewCollection
        Dim item As New HotelView

        item = coll.AddNew
        item.HotelName = "Test 1"
        item = coll.AddNew
        item.HotelName = "Test 2"

        e.Collection = coll

End Sub

 This code produces the following error:

[InvalidCastException: Cast specificato non valido.]
   EntitySpaces.Web.esDataSourceView.FetchTotalRowCount(esDataSourceSelectEventArgs e) +447
   EntitySpaces.Web.esDataSourceView.Select(DataSourceSelectArguments arguments, DataSourceViewSelectCallback callback) +276
   System.Web.UI.WebControls.DataBoundControl.PerformSelect() +142
   System.Web.UI.WebControls.ListView.PerformSelect() +57
   System.Web.UI.WebControls.BaseDataBoundControl.DataBind() +73
   System.Web.UI.WebControls.BaseDataBoundControl.EnsureDataBound() +82
   System.Web.UI.WebControls.ListView.CreateChildControls() +55
   System.Web.UI.Control.EnsureChildControls() +87
   System.Web.UI.Control.PreRenderRecursiveInternal() +44
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +842

But If I don't use the esDataSource in this way:

        <asp:ListView ID="ListView1" runat="server">
            <LayoutTemplate>
                <div>
                    <asp:PlaceHolder ID="itemPlaceholder" runat="server"></asp:PlaceHolder>
                </div>
            </LayoutTemplate>
            <ItemTemplate>
                <%# Eval("HotelName") %><br />
            </ItemTemplate>
        </asp:ListView>

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        Dim coll As New HotelViewCollection
        Dim item As New Viagiar.Business.Objects.HotelView

        item = coll.AddNew
        item.HotelName = "Test 1"
        item = coll.AddNew
        item.HotelName = "Test 2"

        ListView1.DataSource = coll
        ListView1.DataBind()

    End Sub

Thanks Scott, I'm adding things in select event only for test purpose, normally I use EntitySpaces like the example you posted. I tried again with another collection and without the datapager but the error is always the same. With the others controls (Gridview, Repeater, ...) no problem

Well the point is you shouldn't change the row count in the esSelect event as we need to know it for paging. You can try setting AutoPaging="False" on the esDataSource, but you still really shouldn't be adding thing manually in the esSelect event. If you look at our esDataSource samples in our FAQ section you will see that adding/editing/deleting is tracked for you automatically and you should not be doing it manually as this is what the esCreateEntity event is for.

protected void EsDataSource1_esCreateEntity(object sender, EntitySpaces.Web.esDataSourceCreateEntityEventArgs e)
{
	Employees employee = new Employees();
	if (e.PrimaryKeys == null)
	{
		employee.AddNew();
	}
	else
	{
		employee.LoadByPrimaryKey((int)e.PrimaryKeys[0]);
	}

	e.Entity = employee;
}

Ok Scott maybe this example can helps :

 <asp:ListView ID="ListView1" DataSourceID="esdTest" runat="server">
            <LayoutTemplate>
                <div>
                    <asp:PlaceHolder ID="itemPlaceholder" runat="server"></asp:PlaceHolder>
                </div>
            </LayoutTemplate>
            <ItemTemplate>
                <%# Eval("CountryId") %><br />
            </ItemTemplate>
        </asp:ListView>
<cc1:esDataSource ID="esdTest" AutoPaging="False" runat="server" />

    Private Sub esdTest_esSelect(ByVal sender As Object, ByVal e As EntitySpaces.Web.esDataSourceSelectEventArgs) Handles esdTest.esSelect

        Dim query As New CityQuery
        query.OrderBy(query.CountryId.Ascending)

        e.Collection = New CityCollection
        e.Query = query

    End Sub

Hi Mike,

I tried to populate the collection before esSelect but the error continues. If I set the TotalRowCount manually all work. I don't know why in FetchTotalRowCount the argument RetrieveTotalRowCount is always set to True If I don't want to use the Datapager.

Thank you for your help

I think we can address this in our 1st maintenance release. Let me first verify that we are auto fetching the row count if AutoPaging is false, if so, we will fix this, thanx for the post.