Question

I have two dropdownlist and a button. I used the breakpoint in my project and everything is working fine. But as soon I am getting out of the function of the button this is the error I am getting:

Cannot have multiple items selected in a DropDownList.

Here is my code to that button:

 protected void Button1_Click(object sender, EventArgs e)
    {

        if (ddlPlayer1.SelectedItem.Value != "0" || ddlPlayer2.SelectedItem.Value != "0" && ddlPlayer1.SelectedItem.Value != ddlPlayer2.SelectedItem.Value)
        {
            lblPlayer1Score.Text = Repository.Instance.ReturnScore(ddlPlayer1.SelectedValue.ToString(), ddlPlayer2.SelectedValue.ToString()).Rows[0][0].ToString();
            lblPlayer2Score.Text = Repository.Instance.ReturnScore(ddlPlayer2.SelectedValue.ToString(), ddlPlayer1.SelectedValue.ToString()).Rows[0][0].ToString();


        }

        ddlPlayer1.DataBind();
        ddlPlayer2.DataBind();
    }

What I am doing wrong here?

Answer 1

Make sure you are not databinding multiple ddls to the same datasource.
Being selected is an attribute of an item, therefore, if different ddls
select different items from the same datasource, each of the ddls ends up
with multiple items selected which is probably what is happening here..