Basic Filtering with RadListView

[Sergio]

Greetings

I am trying to create a basic filtering functionality similar to the found at the Demo documentation at http://demos.telerik.com/aspnet-ajax/listview/examples/filtering/defaultcs.aspx

The only distinction is that my application uses ObjectDataSource to bind  the RadListView control. Here is a brief about the ObjectDataSource

<asp:ObjectDataSource ID="ObjectDataSource1" runat="server" TypeName="FriendBarDataSet"
    SelectMethod="GetFriends" OnSelecting="ObjectDataSource1_Selecting">
    <SelectParameters>
        <asp:Parameter Name="UserTable" />
    </SelectParameters>
</asp:ObjectDataSource>

  protected void ObjectDataSource1_Selecting(object sender, ObjectDataSourceSelectingEventArgs e)
    {
        e.InputParameters["UserTable"] = UserTable;

    }

/// And in the FriendBarDataSet Class

public SQLiteDataReader GetFriends(string UserTable)
    {
        SQLiteConnection connection = new SQLiteConnection(WebConfigurationManager.ConnectionStrings["ConnectionString2"].ConnectionString);
        SQLiteCommand cmd = new SQLiteCommand();
        cmd.Connection = connection;
        StringBuilder SelectCommand = new StringBuilder();
        string Table = "[" + UserTable.ToString() + "]";
        string SQL = "SELECT [ID], [uid], [Name], [sex], [birthday_date] FROM ";

        string completeCommand = SQL + Table;
        SelectCommand.Append(completeCommand.ToString());
        cmd.CommandText = SelectCommand.ToString();

        connection.Open();
        return cmd.ExecuteReader(CommandBehavior.CloseConnection);
    }

The ListView Binds with No Problem. It is doing what it Suppose to do..

However, when in try to implement a filter similar to the demo one, the filter is not functional and it throws me an error. Here is how i go about Implementing the filter..

if (!String.IsNullOrEmpty(TextBoxFilter.Text))
            {

                RadListViewFriendSelection.FilterExpressions.Clear();
                RadListViewFriendSelection.FilterExpressions.BuildExpression().Contains("Name", TextBoxFilter.Text.Trim()).Build();
                RadListViewFriendSelection.Rebind();

            }

The filer is throwing me the following exception::

System.InvalidOperationException: DataReader has been closed @ RadListViewFriendSelection.Rebind()

Could you help me implement a simple filter into this application? To filter - The "Name" field of the ListView control using "Contains". notice that I am accessing an SQLite data. I don't know if this happen to influence. In which case, I will be open to suggestions of implementing filtering in a different way.

Thank you for your help.

[Maria Ilieva]

Hi Sergio,

Note that when a Data Reader is used the data will be read only once and you could not manipulate them including filtering them and setting a filter expression. Therefore in this case I would suggest you to add the data form the data source in a DataTable and verify if this works for you.


Regards,
Maria Ilieva
the Telerik team

[Sergio]

Thanks Maria

The Filtering functionality of the RadListView I believe uses the Dataview.RowFilter property to filter the rows.

As a result, simarly to ObjectDataSources, the data source needs to be represented by a DataSet, a DataTable, or a DataView Object.

So instead of having my datasource return a SQLiteDataReader, I changed so it returned a DataTable and problem solve. Thought about including this for future references. :-)