Using a DropDownList to filter data

Question

I am working on my first aspx/CR that uses controls on the page to filter the displayed data. I have a crystal report that by default pulls all warehouse data. It is comprised of two separate views. I have added a DropDownList to the aspx page to allow the user to select a single warehouse. I have the crystalReportViewer hidden by default and on the SelectedIndexChanged event of the DropDownList, I have the code to set the crystalReportViewer to visible. I have the code in the ConfigureCrystalReports() section to define the selection criteria. My code is as follows:
    private void ConfigureCrystalReports()
        if (!IsPostBack)
            crystalReportViewer.Visible = false;
        else
            string warehouse = ddlWarehouse.SelectedValue;
            string selectFormula = "{VW_CURRENT_INVENTORY_GL.WH}=" + warehouse;
            crystalReportViewer.SelectionFormula = selectFormula;
<snipped>
    protected void ddlWarehouse_SelectedIndexChanged(object sender, EventArgs e)
        crystalReportViewer.Visible = true;
The page loads with no errors and the report is hidden, but when I select a valid warehouse, I get this error because it's not capturing the value in the dropdownlist correctly:
A number, currency amount, boolean, date, time, date-time, or string is expected here. Details: errorKind Error in File CURRINV_GL_NOLOT_PROD {7FCFCEBF-94D6-4DF0-BA8E-816763C625B8}.rpt: Error in formula Record Selection: '{VW_CURRENT_INVENTORY_GL.WH}=Select Warehouse' A number, currency amount, boolean, date, time, date-time, or string is expected here. Details: errorKind
If I put Response.Write(selectFormula) right after the selectFormula is set, it's not getting the value in the DropDownList - it's keeping the generic "Select Warehouse" which is the default value in the dropdownlist. I tried moving that definition to the SelectedIndexChanged event, but it's not working correctly. I tried adding crystalReportViewer.DataBind() in the selectedindexchanged event but it's still not getting the updated value in the dropdownlist. I need that to fire anytime they change the value in the dropdownlist and then have the report refresh with the new data.

Answer 1

I got this working right after I submitted this question. I ended up moving the whole selectFormula definition to the SelectedIndexChanged event and it works like a charm.