Select Random Quiz question from Database using C# and VB.Net in ASP.Net

Hi irshad1231,

Refer below sample.

HTML

<div>
    <div id="dvQuestion" runat="server">
        <h1>
            <asp:Label ID="lblQuestion" runat="server" />
            <asp:HiddenField runat="server" ID="hfQuestionId" />
        </h1>
        <asp:RadioButtonList ID="rbtnOptions" runat="server">
        </asp:RadioButtonList>
        <br />
        <asp:Button ID="btnNext" Text="Next" runat="server" OnClick="Next" />
    </div>
    <div id="dvResult" runat="server" visible="false">
        <h1>
            <asp:Label ID="lblResult" runat="server" />
        </h1>
    </div>
</div>

Namespaces

C#

using System.Data;
using System.Configuration;
using System.Data.SqlClient;

Code

C#

private DataTable DataTableQuestions
{
    get { return (DataTable)ViewState["Questions"]; }
    set { ViewState["Questions"] = value; }
}
private int Score
{
    get { return (int)ViewState["Score"]; }
    set { ViewState["Score"] = value; }
}
static int QuestionId;
static int attemptCount = 0;
protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        Score = 0;
        QuestionId = 1;
        DataTableQuestions = PopulateQuestions();
        GetCurrentQuestion(Convert.ToInt32(DataTableQuestions.Rows[QuestionId - 1]["QuestionId"]), PopulateQuestions());
    }
}

protected void Next(object sender, EventArgs e)
{
    if (QuestionId <= DataTableQuestions.Rows.Count)
    {
        if (rbtnOptions.SelectedIndex != -1)
        {
            string otionSelected = rbtnOptions.SelectedItem.Text.Trim();
            string correctAnswer = CorrectAnswer(Convert.ToInt32(hfQuestionId.Value));

            if (otionSelected.ToLower() != correctAnswer.ToLower())
            {
                attemptCount++;
            }
            else
            {
                attemptCount = 0;
            }
            if (attemptCount >= 1)
            {
                ClientScript.RegisterClientScriptBlock(this.GetType(), "", "alert('Answer is Wrong. Try Again')", true);
            }
            else
            {
                QuestionId++;
                if (otionSelected.ToLower() == correctAnswer.ToLower())
                {
                    Score++;
                    ClientScript.RegisterClientScriptBlock(this.GetType(), "", "alert('Answer is Correct')", true);
                }
                GetCurrentQuestion(QuestionId, DataTableQuestions);
                attemptCount = 0;
            }
        }
    }
}

private void GetCurrentQuestion(int questionId, DataTable dtQuestions)
{
    if (QuestionId <= dtQuestions.Rows.Count)
    {
        lblQuestion.Text = dtQuestions.Rows[questionId - 1]["QuestionDescription"].ToString();
        hfQuestionId.Value = dtQuestions.Rows[questionId - 1]["QuestionId"].ToString();
        DataTable dtOptions = PopulateOptions(Convert.ToInt16(hfQuestionId.Value));
        List<ListItem> options = new List<ListItem>();
        for (int i = 0; i < dtOptions.Rows.Count; i++)
        {
            options.AddRange(new ListItem[] { new ListItem(dtOptions.Rows[i][1].ToString(), i.ToString()) });
        }
        rbtnOptions.Items.Clear();
        rbtnOptions.Items.AddRange(options.ToArray());
        rbtnOptions.DataBind();
    }
    else
    {
        dvQuestion.Visible = false;
        dvResult.Visible = true;
        lblResult.Text = string.Format("You Scored {0}/{1}", Score, QuestionId - 1);
    }
}

private DataTable PopulateQuestions()
{
    DataTable dt = new DataTable();
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT QuestionId,QuestionDescription,'' AnswerSelected FROM QuestionTable ORDER BY NEWID()", con))
        {
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))
            {
                con.Open();
                da.Fill(dt);
                con.Close();
            }
        }
    }
    return dt;
}

private DataTable PopulateOptions(int questionId)
{
    DataTable dt = new DataTable();
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT QuestionId,Options FROM OptionTable WHERE QuestionId = @QuestionId", con))
        {
            cmd.Parameters.AddWithValue("@QuestionId", questionId);
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))
            {
                con.Open();
                da.Fill(dt);
                con.Close();
            }
        }
    }
    return dt;
}

private string CorrectAnswer(int questionId)
{
    string answer = "";
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT Answer FROM AnswerTable WHERE QuestionId = @QuestionId", con))
        {
            cmd.Parameters.AddWithValue("@QuestionId", questionId);
            con.Open();
            answer = cmd.ExecuteScalar().ToString();
            con.Close();
        }
    }
    return answer;
}