Access data from dynamically created controls

 The problem is with adding controls to panel logic.

 The Panel.Control.Count is always 1.

As this is accessing SQL Server Reporting Services, there's apparently a ReportParameterInfoCollection and ReportParameterInfo that may help here.

I've located a job that works for WinForm; I going to try to modify it to work for WebForms.

Thanks for all your help,
Michell

I think the problem is in your btnNewScenarioName_Click method.

Assume that the user clicks on Ok (which loads true in the hidden field) then you are trying to

int scenarioID = Convert.ToInt32(grdSavedScenarios.SelectedDataKey.Value);
UpdateParameters(scenarioID);
LoadScenario(scenarioID);

Here UpdateParameters (which essentially gets all the values from the dynamically generated code) is called before you actually load the scenario(where you dynamically load the controls)

HTH.

Happy Programming!!!

Regards,
Raja

PS. All your other code is perfect as far as I can see and would work fine :-)....Saving data to viewstate is a bad programming practice and a performance hit too.

Here are the appropriate methods:

protected void btnNewScenarioName_Click(object sender, EventArgs e)
{
        // OnClientClick executes a Javascript "confirm", asking the user if he wants to over-write the existing report
        // parameter values, which writes the result ("true"/"false") to a
        // asp:HiddenField called hdnConfirm

        string confirm = hdnConfirm.Value.ToString();

        if (confirm == "false")        // don't overwrite the existing parameter values. I'll change the name of the report
        {
                int scenarioID = Convert.ToInt32(grdSavedScenarios.SelectedDataKey.Value);
                LoadScenario(scenarioID);         // to refresh the Scenario gridview
                txtNewScenarioName.Focus();        // this doesn't seem to be working either. I'm assuming it's the postback
        } // end if
        else
        {
                int scenarioID = Convert.ToInt32(grdSavedScenarios.SelectedDataKey.Value);
                UpdateParameters(scenarioID);
                LoadScenario(scenarioID);
        } // end else

 } // end method btnNewScenarioName_Click

private void LoadScenario(int scenarioID)
{
        Parameters dal = new Parameters();                // DAL class
        DataSet ds = dal.GetSavedParameters(scenarioID);

        for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
        {
                DataRow dr = ds.Tables[0].Rows[i];
                Label lbl = new Label();
                Literal ltl = new Literal();
                TextBox txt = new TextBox();

                lbl.ID = "lbl" + i.ToString();
                lbl.Text = dr["ParameterName"].ToString();

                ltl.ID = "ltl" + i.ToString();
                ltl.Text = "
";

                txt.ID = "txt" + i.ToString();
                txt.Text = dr["ParameterValue"].ToString();

                pnlParameters.Controls.Add(lbl);
                pnlParameters.Controls.Add(txt);
                pnlParameters.Controls.Add(ltl);
        } // end for
} // end method LoadScenarios

private void UpdateParameters(int scenarioID)
{
        Parameters dal = new Parameters();        // DAL

        DataSet ds = dsl.GetSavedParameters(scenarioID);
        DataTable dt = ds.Tables[0];

        foreach (DataRow row in dt.Rows)
        {
                for (int i = 0; i < dt.Rows.Count; i++)
                {
                        string labelName = "lbl" + i.ToString();
                        string valueName = "parm" + i.ToString();

                        Label lblName = (Label)pnlParameters.FindControl(labelName); // Label returns null

                        TextBox txtValue = (TextBox)pnlParameters.FindControl(valueName); // TextBox returns null
                } // end for
        } // end foreach
} // end method UpdateParameters

// this is as far as I've gotten. with the controls returning "null", there's no sense
// in trying to get the values from them.                        

I'm thinking maybe I could create a dynamic method for TextBox_TextChanged. That could stored the appropriate values, together with the associated names into a ViewState control, or into HiddenFields. Only concern there is to ensure that I have enough controls to hang on to everything.

Any other ideas?

Thanks,
Michell

Can you post your actual code so that it would be easy for anyone to help? Without seeing the actual events its kinda difficult to suggest any solution.

Regards,
Raja

I see.

That could be a problem. Can I use ViewState to keep track of the new values the user has entered?

Michell

Are you loading the report data (parameters) on Page_Load and generating those controls? If so check if you have checked like this

if (!this.IsPostBack)
{
        //Load the report parameter data
}

If you had not checked this then on Postback (due to button click) it is going to bring back the data again and load the controls. This could be why the it is returning null when you try to find it.

HTH.

Happy Programming!!!

Regards,
Raja

Raja,

Thanks for your input.

This is, in fact triggered by a button_click, and a postback is involved.

Am I missing something there?

Thanks,
Michell

I cannot see anything wrong with your code. But one thing which used to get me almost every time is the check for "IsPostBack" in the page_load. See if that is the case in your code.

HTH.

Happy Programming!!!

Regards,
Raja