CODEWITHSUNDEEP
c#asp.netsql
user3622983
user3622983

Reputation: 5

Multiple controls with the same ID 'ddl_Weight' were found. FindControl requires that controls have unique IDs

I am having this error: Multiple controls with the same ID 'ddl_Weight' were found. Find-control requires that controls have unique IDs. thus i am not add to add more objective text-box, drop-down list. I have to add objectives, drop-down list for weightage and achieved.

private List<DropDownList> inputDropDownList;
    private List<DropDownList> inputDropDownList2;

    protected void btn_AddObjectives_Click(object sender, EventArgs e)
    {
        int rowCount = 0;

        //initialize a session.
        rowCount = Convert.ToInt32(Session["clicks"]);

        rowCount++;

        //In each button click save the numbers into the session.
        Session["clicks"] = rowCount;


        //Create the textboxes and labels each time the button is clicked.
        for (int i = 0; i < rowCount; i++)
        {

            TextBox TxtBoxO = new TextBox();
            TxtBoxO.TextMode = TextBoxMode.MultiLine;
            DropDownList DDLW = new DropDownList();
            DropDownList DDLA = new DropDownList();
            inputDropDownList = new List<DropDownList>();
            inputDropDownList2 = new List<DropDownList>();

            Label lblO = new Label();
            Label lblW = new Label();
            Label lblA = new Label();

            TxtBoxO.ID = "TextBoxO" + i.ToString();
            DDLW.ID = "DDLW" + i.ToString();
            DDLA.ID = "DDLA" + i.ToString();

            inputDropDownList.Add(DDLW);
            inputDropDownList2.Add(DDLA);

            TxtBoxO.Width = 325;
            DDLW.Height = 25;
            DDLA.Height = 25;


            DDLA.ID = "ddl_Achieved";
            DDLA.Items.Add("Select");
            DDLA.Items.Add("5");
            DDLA.Items.Add("10");
            DDLA.Items.Add("15");
            DDLA.Items.Add("20");
            DDLA.Items.Add("25");
            DDLA.Items.Add("30");
            DDLA.Items.Add("35");
            DDLA.Items.Add("40");
            DDLA.Items.Add("45");
            DDLA.Items.Add("50");
            DDLA.Items.Add("55");
            DDLA.Items.Add("60");
            DDLA.Items.Add("65");
            DDLA.Items.Add("70");
            DDLA.Items.Add("75");
            DDLA.Items.Add("80");
            DDLA.Items.Add("85");
            DDLA.Items.Add("90");
            DDLA.Items.Add("95");
            DDLA.Items.Add("100");

            DDLW.ID = "ddl_Weight"; 
            DDLW.Items.Add("Select");
            DDLW.Items.Add("5");
            DDLW.Items.Add("10");
            DDLW.Items.Add("15");
            DDLW.Items.Add("20");
            DDLW.Items.Add("25");
            DDLW.Items.Add("30");
            DDLW.Items.Add("35");
            DDLW.Items.Add("40");
            DDLW.Items.Add("45");
            DDLW.Items.Add("50");
            DDLW.Items.Add("55");
            DDLW.Items.Add("60");
            DDLW.Items.Add("65");
            DDLW.Items.Add("70");
            DDLW.Items.Add("75");
            DDLW.Items.Add("80");
            DDLW.Items.Add("85");
            DDLW.Items.Add("90");
            DDLW.Items.Add("95");
            DDLW.Items.Add("100");

            lblO.ID = "LabelO" + i.ToString();
            lblW.Text = "LabelW" + i.ToString();
            lblA.ID = "LabelA" + i.ToString();

            lblO.Text = "Objective " + " " + (i + 1).ToString() + " : ";
            lblW.Text = " Weightage" + " " + (i + 1).ToString() + " : ";
            lblA.Text = " Achieved " + " " + (i + 1).ToString() + " : ";


            //Add the labels and textboxes to the Panel.
            Panel1.Controls.Add(lblO);
            Panel1.Controls.Add(TxtBoxO);

            Panel1.Controls.Add(lblW);
            Panel1.Controls.Add(DDLW);

            Panel1.Controls.Add(lblA);
            Panel1.Controls.Add(DDLA);
        }

Upvotes: 0

Views: 4868

Answers (1)

David
David

Reputation: 219027

The error is pretty clear. You're adding multiple controls with the same ID, which is disallowed. Note that you're in a loop:

for (int i = 0; i < rowCount; i++)

We'll assume that rowCount is greater than 1 and that the loop iterates more than once. Within that loop you create controls:

DropDownList DDLW = new DropDownList();
DropDownList DDLA = new DropDownList();

And you assign IDs to them:

DDLW.ID = "DDLW" + i.ToString();
DDLA.ID = "DDLA" + i.ToString();

These IDs are probably unique. But then you overwrite them with ones that are not unique:

DDLA.ID = "ddl_Achieved";
DDLW.ID = "ddl_Weight";

And then you add them to the page:

Panel1.Controls.Add(DDLW);
Panel1.Controls.Add(DDLA);

The purpose of an ID, as its name suggests, is to uniquely identify an object. Just like with id attributes in HTML, if you re-use the same one multiple times in a page then the behavior becomes undefined. The system (in this case wherever you're using FindControl()) expects there to be 0 or 1 elements with any given ID value. You've created more then 1, which is invalid.

You can probably just remove the lines where you set the non-unique IDs and keep the lines where you set the unique ones.

Upvotes: 2

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