create property and set the data table from the public method. in page load you can bind the data
public DataTable MyData { get; set; }
protected void Page_Load(object sender, EventArgs e)
{
DropDownList1.DataSource =MyData ;
DropDownList1.DataBind();
}
public void SetData(DataSet dTLookupValues)
{
MyData = dTLookupValues.Tables[0];
}
in your main page
protected void Page_Load(object sender, EventArgs e)
{
var control = (LookupGrid )LoadControl("~/LookupGrid.ascx");
control.SetData(lookupvalues.ToDataSet());
Panel1.Controls.Add(control); //add control to your page or panel
}