Passing SqlDataSource Object An Array As A Parameter

Hi,

I am trying to get the selected options from a listbox and either pass a SqlDataSource object the array or loop through it and pass each element of the array. I then need to modify the returned databtable to graphing function, but first drop the last column. I was wondering if anyone can help me with the following:

1. Pass an array into SqlDataSource Select OR 
2. Pass a single argument into the Select statement and populate a datatable without it writing over the current row each time it iterates through the foreach statement. I am looking for the dataview to append to dt each time it loops. Is there a property for dataview that behaves like the "ClearBeforeFill" for table adapters?
3. Update a parameter programmatically

Below code works, but I think it can be more efficient. Any suggestions would be greatly appreciated.

Thanks in advance!!

 

 

        DataTable dt = new DataTable();
        DataTable dt2 = new DataTable();
        DataView dv = new DataView();
                        

       foreach(ListItem liOptions in ListBox1.Items)
       {
             if(liOptions.Selected)
             {                   
                   SqlDataSource1.SelectParameters.Add("Parameter1", liOptions);
                   dv = (DataView)SqlDataSource1.Select(DataSourceSelectArguments.Empty);
                   dt2 = dv.Table;
                   dt.Merge(dt2);
                   dt2.Dispose();
                   SqlDataSource1.SelectParameters.Clear();
             }
       }


        if (dt.Rows.Count > 0)
        {
           Graph(dt);                             //Pass original datatable (dt) to Graph();
           dt.Columns.RemoveAt(2);      //Reformat datatable (dt) and remove last column before binding to Gridview1

           GridView1.DataSource = dt;
           GridView1.DataBind();
        } else {

    errorMessage.Text = "No data was returned!";
 }