Web Questionnaire App in ASP.NET Web Forms

Question

I did some research and couldn’t find the correct term to correct my mistake. I created a Appweb where the user chooses a subject in a DropDownList and this loads a questionnaire from the database.
What happens is that if there is simultaneous access several different errors occur:

1. The most recurrent is the first user questionnaire to be loaded for the second, even if he chose another option in DropDownList.
2. If I choose an option on DropDownList, load the questionnaire and return immediately to choose another option, is loaded to first option. Whereas, if I take a while and do the same process, load new choice.

I checked in the browser that the request is correct (Params) but the answer (Response) sends the page according to the previous parameters.

Apparently it is not accepting more than a user doing the questionnaire, and the server keeps the first choice in the cache and does not update the page even with a new parameter. I hope you have understood and can help me.
Aspx code:

<asp:Content ID="BodyContent" ContentPlaceHolderID="MainContent" runat="server">
    <style type="text/css">
    .modalPopup
    {
    background-color: #fffddd;
    padding: 3px;
    z-index: 10001;
    }
    </style>
    <div class="panel panel-default">
        <div id="divtest" runat="server">
             <asp:Label ID="label" runat="server" Text="Escolha uma disciplina abaixo:"></asp:Label>

             <asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="true" CssClass="dropdown form-control" OnSelectedIndexChanged="btnCarregarClick">
                                    <asp:ListItem Enabled="false">Português</asp:ListItem>
                                    <asp:ListItem >Racíocinio</asp:ListItem>
                                    <asp:ListItem Enabled="false">História</asp:ListItem>
                                    <asp:ListItem Enabled="false">Geografia</asp:ListItem>
                                    <asp:ListItem >Direito Constitucional</asp:ListItem>
                                    <asp:ListItem >Outros Direitos</asp:ListItem>
                                </asp:DropDownList>

            <asp:Button ID="btnCarregar" runat="server" Text="Carregar" CssClass ="btn btn-primary" OnClick="btnCarregarClick"/>
        </div>
            <div class ="panel-body col-md-12">
                <asp:Panel ID="UpdPanel" runat="server">

                    <table id="tbl">
                        <tr>
                        <asp:Label ID="Label1" runat="server" Text="Label" Visible="false"></asp:Label>      
                            <asp:RadioButtonList ID="RadioButtonList1" runat="server" OnSelectedIndexChanged="rdbList1_SelectedIndexChanged"></asp:RadioButtonList>
                        </tr><tr>
                        <asp:Label ID="Label2" runat="server" Text="Label" Visible="false"></asp:Label>
                            <asp:RadioButtonList ID="RadioButtonList2" runat="server" OnSelectedIndexChanged="rdbList2_SelectedIndexChanged"></asp:RadioButtonList></tr><tr>
                        <asp:Label ID="Label3" runat="server" Text="Label" Visible="false"></asp:Label>
                            <asp:RadioButtonList ID="RadioButtonList3" runat="server" OnSelectedIndexChanged="rdbList3_SelectedIndexChanged"></asp:RadioButtonList></tr><tr>
                        <asp:Label ID="Label4" runat="server" Text="Label" Visible="false"></asp:Label>
                            <asp:RadioButtonList ID="RadioButtonList4" runat="server" OnSelectedIndexChanged="rdbList4_SelectedIndexChanged"></asp:RadioButtonList></tr><tr>
                        <asp:Label ID="Label5" runat="server" Text="Label" Visible="false"></asp:Label>
                            <asp:RadioButtonList ID="RadioButtonList5" runat="server" OnSelectedIndexChanged="rdbList5_SelectedIndexChanged"></asp:RadioButtonList></tr><tr>
                        <asp:Label ID="Label6" runat="server" Text="Label" Visible="false"></asp:Label>
                            <asp:RadioButtonList ID="RadioButtonList6" runat="server" OnSelectedIndexChanged="rdbList6_SelectedIndexChanged"></asp:RadioButtonList></tr><tr>
                        <asp:Label ID="Label7" runat="server" Text="Label" Visible="false"></asp:Label>
                            <asp:RadioButtonList ID="RadioButtonList7" runat="server" OnSelectedIndexChanged="rdbList7_SelectedIndexChanged"></asp:RadioButtonList></tr><tr>
                        <asp:Label ID="Label8" runat="server" Text="Label" Visible="false"></asp:Label>
                            <asp:RadioButtonList ID="RadioButtonList8" runat="server" OnSelectedIndexChanged="rdbList8_SelectedIndexChanged"></asp:RadioButtonList></tr><tr>
                        <asp:Label ID="Label9" runat="server" Text="Label" Visible="false"></asp:Label>
                            <asp:RadioButtonList ID="RadioButtonList9" runat="server" OnSelectedIndexChanged="rdbList9_SelectedIndexChanged"></asp:RadioButtonList></tr><tr>
                        <asp:Label ID="Label10" runat="server" Text="Label" Visible="false"></asp:Label>      
                            <asp:RadioButtonList ID="RadioButtonList10" runat="server" OnSelectedIndexChanged="rdbList10_SelectedIndexChanged"></asp:RadioButtonList></tr>

                    </table>
                </asp:Panel>  
                    <asp:Button Visible="false" ID="btnCorrigir" runat="server" Text="Corrigir" CssClass ="btn btn-primary" OnClick="btnCorrigir_Click"/>
                    <asp:Label ID="lbll" Visible="false" Style="font-size:x-large" runat="server"></asp:Label>
                    <asp:Label ID="lblll" Visible="false" runat="server">Clique em gabarito para vê-lo.</asp:Label>
                    <asp:Button ID="btnok" CssClass="btn btn-primary" Visible="false" runat="server" Text="Gabarito" OnClick="btnok_click" />
                    <asp:LinkButton ID="Linkbtn" CssClass="btn btn-danger" Visible="false" runat="server" Text="Voltar" PostBackUrl="~/Default.aspx" />
                    <div ID="div" runat="server" visible="False">     
                        <asp:Panel ID="Panel1" runat="server" CssClass="modalPopup" Style="display: table" >
                            <table style="width: 270px">
                            <tr>
                            <td>
                                <asp:Label ID="lblGabarito" runat="server" Height="30px" Text="Gabarito"></asp:Label>
                            </td>
                            </tr>
                            <tr>
                            <td style="width: 30% ">
                                <asp:Label ID="lblPergunta1" runat="server" Height="30px"></asp:Label>
                                <asp:Label ID="lblPergunta2" runat="server" Height="30px"></asp:Label>
                                <asp:Label ID="lblPergunta3" runat="server" Height="30px"></asp:Label>
                                <asp:Label ID="lblPergunta4" runat="server" Height="30px"></asp:Label>
                                <asp:Label ID="lblPergunta5" runat="server" Height="30px"></asp:Label>
                                <asp:Label ID="lblPergunta6" runat="server" Height="30px"></asp:Label>
                                <asp:Label ID="lblPergunta7" runat="server" Height="30px"></asp:Label>
                                <asp:Label ID="lblPergunta8" runat="server" Height="30px"></asp:Label>
                                <asp:Label ID="lblPergunta9" runat="server" Height="30px"></asp:Label>
                                <asp:Label ID="lblPergunta10" runat="server" Height="30px"></asp:Label>
                            </td>  
                            </tr>
                            <tr>
                            <td >
                            </td>
                            <td> &nbsp; &nbsp; &nbsp;
                                <asp:Button ID="btnT" CssClass="btn btn-xs" runat="server" Text="Encerrar" /></td>
                            </tr>
                            </table>
                            </asp:Panel> 
                    </div>
                    <asp:ModalPopupExtender ID="ModalPopupExtenderLogin" runat="server"
                        TargetControlID="btnok"
                        PopupControlID="Panel1"
                        BackgroundCssClass="modalBackground"
                        DropShadow="true"
                        CancelControlID="btnT" /> 

            </div>    
    </div>
</asp:Content>

Code C#:

 namespace dygaquiz
{
    public partial class Questionario : System.Web.UI.Page
    {
        int count, rbl1, rbl2, rbl3, rbl4, rbl5, rbl6, rbl7, rbl8, rbl9, rbl10;
        Crud crud = new Crud();
        static List<QuestionarioDados> questio = new List<QuestionarioDados>();
        public class QuestionarioDados
        {
            public int Id { get; set; }
            public string Pergunta { get; set; }
            public int certa { get; set; }
            public DataSet Ds { get; set; }
        }
        protected void Page_Load(object sender, EventArgs e)
        {

        }
        protected void btnok_click(object sender, EventArgs e)
        {
            ModalPopupExtenderLogin.Show();
        }
        protected void btnCarregarClick(object sender, EventArgs e)
        {

            CarregarQuestionario(DropDownList1.SelectedIndex);
            div.Visible = true;

        }
        protected void btnCorrigir_Click(object sender, EventArgs e)
        {
            count = 0;
            Corrigir();
            btnCorrigir.Visible = false;
        }
        public void Corrigir()
        {

            if (RadioButtonList1.SelectedItem != null)
            {
                if (questio[0].certa.ToString() == rbl1.ToString())
                {
                    RadioButtonList1.SelectedItem.Attributes.Add("style", "background-color:green");
                    count++;
                }
                else
                {
                    RadioButtonList1.SelectedItem.Attributes.Add("style", "background-color:red");

                }
            }
            if (RadioButtonList2.SelectedItem != null)
            {
                if (questio[1].certa.ToString() == rbl2.ToString())
                {
                    RadioButtonList2.SelectedItem.Attributes.Add("style", "background-color:green");
                    count++;
                }
                else
                {
                    RadioButtonList2.SelectedItem.Attributes.Add("style", "background-color:red");

                }
            }
            if (RadioButtonList3.SelectedItem != null)
            {
                if (questio[2].certa.ToString() == rbl3.ToString())
                {
                    RadioButtonList3.SelectedItem.Attributes.Add("style", "background-color:green");
                    count++;
                }
                else
                {
                    RadioButtonList3.SelectedItem.Attributes.Add("style", "background-color:red");

                }
            }
            if (RadioButtonList4.SelectedItem != null)
            {
                if (questio[3].certa.ToString() == rbl4.ToString())
                {
                    RadioButtonList4.SelectedItem.Attributes.Add("style", "background-color:green");
                    count++;
                }
                else
                {
                    RadioButtonList4.SelectedItem.Attributes.Add("style", "background-color:red");

                }
            }
            if (RadioButtonList5.SelectedItem != null)
            {
                if (questio[4].certa.ToString() == rbl5.ToString())
                {
                    RadioButtonList5.SelectedItem.Attributes.Add("style", "background-color:green");
                    count++;
                }
                else
                {
                    RadioButtonList5.SelectedItem.Attributes.Add("style", "background-color:red");

                }
            }
            if (RadioButtonList6.SelectedItem != null)
            {
                if (questio[5].certa.ToString() == rbl6.ToString())
                {
                    RadioButtonList6.SelectedItem.Attributes.Add("style", "background-color:green");
                    count++;
                }
                else
                {
                    RadioButtonList6.SelectedItem.Attributes.Add("style", "background-color:red");

                }
            }
            if (RadioButtonList7.SelectedItem != null)
            {
                if (questio[6].certa.ToString() == rbl7.ToString())
                {
                    RadioButtonList7.SelectedItem.Attributes.Add("style", "background-color:green");
                    count++;
                }
                else
                {
                    RadioButtonList7.SelectedItem.Attributes.Add("style", "background-color:red");

                }
            }
            if (RadioButtonList8.SelectedItem != null)
            {
                if (questio[7].certa.ToString() == rbl8.ToString())
                {
                    RadioButtonList8.SelectedItem.Attributes.Add("style", "background-color:green");
                    count++;
                }
                else
                {
                    RadioButtonList8.SelectedItem.Attributes.Add("style", "background-color:red");

                }
            }
            if (RadioButtonList9.SelectedItem != null)
            {
                if (questio[8].certa.ToString() == rbl9.ToString())
                {
                    RadioButtonList9.SelectedItem.Attributes.Add("style", "background-color:green");
                    count++;
                }
                else
                {
                    RadioButtonList9.SelectedItem.Attributes.Add("style", "background-color:red");

                }
            }
            if (RadioButtonList10.SelectedItem != null)
            {
                if (questio[9].certa.ToString() == rbl10.ToString())
                {
                    RadioButtonList10.SelectedItem.Attributes.Add("style", "background-color:green");
                    count++;
                }
                else
                {
                    RadioButtonList10.SelectedItem.Attributes.Add("style", "background-color:red");

                }
            }
            if (count == 1)
            {
                lbll.Text = "Acertou " + count.ToString() + " questão.";
            }
            if (count == 0)
            {
                lbll.Text = "Não acertou questão alguma.";
            }
            if (count > 1)
            {
                lbll.Text = "Acertou " + count.ToString() + " questões.";
            }
            btnCorrigir.Visible = false;
            btnok.Visible = true;
            Linkbtn.Visible = true;
            lblll.Visible = true;
            lblPergunta1.Text = "Questão 1: " + ((int)questio[0].certa + 1);
            lblPergunta2.Text = "Questão 2: " + ((int)questio[1].certa + 1);
            lblPergunta3.Text = "Questão 3: " + ((int)questio[2].certa + 1);
            lblPergunta4.Text = "Questão 4: " + ((int)questio[3].certa + 1);
            lblPergunta5.Text = "Questão 5: " + ((int)questio[4].certa + 1);
            lblPergunta6.Text = "Questão 6: " + ((int)questio[5].certa + 1);
            lblPergunta7.Text = "Questão 7: " + ((int)questio[6].certa + 1);
            lblPergunta8.Text = "Questão 8: " + ((int)questio[7].certa + 1);
            lblPergunta9.Text = "Questão 9: " + ((int)questio[8].certa + 1);
            lblPergunta10.Text = "Questão 10: " + ((int)questio[9].certa + 1);
            questio.Clear();
        }
        protected void rdbList1_SelectedIndexChanged(object sender, EventArgs e)
        {

            rbl1 = RadioButtonList1.SelectedIndex;
        }
        protected void rdbList2_SelectedIndexChanged(object sender, EventArgs e)
        {
            //pega o index da lista de radio
            rbl2 = RadioButtonList2.SelectedIndex;
        }
        protected void rdbList3_SelectedIndexChanged(object sender, EventArgs e)
        {
            //pega o index da lista de radio
            rbl3 = RadioButtonList3.SelectedIndex;
        }
        protected void rdbList4_SelectedIndexChanged(object sender, EventArgs e)
        {
            //pega o index da lista de radio
            rbl4 = RadioButtonList4.SelectedIndex;
        }
        protected void rdbList5_SelectedIndexChanged(object sender, EventArgs e)
        {
            //pega o index da lista de radio
            rbl5 = RadioButtonList5.SelectedIndex;
        }
        protected void rdbList6_SelectedIndexChanged(object sender, EventArgs e)
        {
            //pega o index da lista de radio
            rbl6 = RadioButtonList6.SelectedIndex;
        }
        protected void rdbList7_SelectedIndexChanged(object sender, EventArgs e)
        {
            //pega o index da lista de radio
            rbl7 = RadioButtonList7.SelectedIndex;
        }
        protected void rdbList8_SelectedIndexChanged(object sender, EventArgs e)
        {
            //pega o index da lista de radio
            rbl8 = RadioButtonList8.SelectedIndex;
        }
        protected void rdbList9_SelectedIndexChanged(object sender, EventArgs e)
        {
            //pega o index da lista de radio
            rbl9 = RadioButtonList9.SelectedIndex;
        }
        protected void rdbList10_SelectedIndexChanged(object sender, EventArgs e)
        {
            //pega o index da lista de radio
            rbl10 = RadioButtonList10.SelectedIndex;
        }
        public void CarregarQuestionario(int a)
        {
            Label1.Visible = true;
            Label2.Visible = true;
            Label3.Visible = true;
            Label4.Visible = true;
            Label5.Visible = true;
            Label6.Visible = true;
            Label7.Visible = true;
            Label8.Visible = true;
            Label9.Visible = true;
            Label10.Visible = true;
            btnCorrigir.Visible = true;
            lbll.Visible = true;
            int x = 0;
            if (crud.Read(a) != null)
            {
                foreach (DataRow row in crud.Read(a).Rows)
                {

                    int id = (int)row["Id"];
                    string pergunta = row["pergunta"].ToString();
                    int certa = (int)row["certa"];
                    x++;
                    if (crud.Read2(id) != null)
                    {
                        DataSet ds = new DataSet(); ds.Tables.Add(crud.Read2(id));
                        questio.Add(new QuestionarioDados() { Ds = ds, Id = id, Pergunta = pergunta, certa = certa });
                    }
                    else
                        questio.Add(new QuestionarioDados() { Id = id, Pergunta = pergunta, certa = certa });
                }
                if (questio[0] != null)
                {
                    Label1.Text = questio[0].Pergunta;
                    RadioButtonList1.DataSource = questio[0].Ds;
                    RadioButtonList1.DataTextField = "Resposta";
                    RadioButtonList1.DataBind();
                }
                if (questio[1] != null)
                {
                    Label2.Text = questio[1].Pergunta;
                    RadioButtonList2.DataSource = questio[1].Ds;
                    RadioButtonList2.DataTextField = "Resposta";
                    RadioButtonList2.DataBind();
                }
                if (questio[2] != null)
                {
                    Label3.Text = questio[2].Pergunta;
                    RadioButtonList3.DataSource = questio[2].Ds;
                    RadioButtonList3.DataTextField = "Resposta";
                    RadioButtonList3.DataBind();
                }
                if (questio[3] != null)
                {
                    Label4.Text = questio[3].Pergunta;
                    RadioButtonList4.DataSource = questio[3].Ds;
                    RadioButtonList4.DataTextField = "Resposta";
                    RadioButtonList4.DataBind();
                }
                if (questio[4] != null)
                {
                    Label5.Text = questio[4].Pergunta;
                    RadioButtonList5.DataSource = questio[4].Ds;
                    RadioButtonList5.DataTextField = "Resposta";
                    RadioButtonList5.DataBind();
                }
                if (questio[5] != null)
                {
                    Label6.Text = questio[5].Pergunta;
                    RadioButtonList6.DataSource = questio[5].Ds;
                    RadioButtonList6.DataTextField = "Resposta";
                    RadioButtonList6.DataBind();
                }
                if (questio[6] != null)
                {
                    Label7.Text = questio[6].Pergunta;
                    RadioButtonList7.DataSource = questio[6].Ds;
                    RadioButtonList7.DataTextField = "Resposta";
                    RadioButtonList7.DataBind();
                }
                if (questio[7] != null)
                {
                    Label8.Text = questio[7].Pergunta;
                    RadioButtonList8.DataSource = questio[7].Ds;
                    RadioButtonList8.DataTextField = "Resposta";
                    RadioButtonList8.DataBind();
                }
                if (questio[8] != null)
                {
                    Label9.Text = questio[8].Pergunta;
                    RadioButtonList9.DataSource = questio[8].Ds;
                    RadioButtonList9.DataTextField = "Resposta";
                    RadioButtonList9.DataBind();
                }
                if (questio[9] != null)
                {
                    Label10.Text = questio[9].Pergunta;
                    RadioButtonList10.DataSource = questio[9].Ds;
                    RadioButtonList10.DataTextField = "Resposta";
                    RadioButtonList10.DataBind();
                }
            }
        }
    }
}

Answer 1

I saw that in your webform has a static variable "Static List questio = new List()", this makes this variable the same for all instances of your webform and this may be the cause of your problem.

Check this variable by removing "Static" and see if it solves the problem.