Randomize questions in VB.NET

Question

User-1578974752 posted

How can I randomize the questions in a test. There are 30 question in the Test1

When the user Max login for attempting the Test,Test1 must show randomized question(For eg-> Code must pick any 10 randomly from 30 questions)

Answer 1

User-369506445 posted

hi

you can use Random class below like

Private r As New Random()
    Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim count As Integer = 5
        Dim questions() As String = {"Question 1: ...", "Question 2: ...", "Question 3: ...", "Question 4: ...", "Question 5: ...", "Question 6: ...", "Question 7: ...", "Question 8: ...", "Question 9: ...", "Question 10: ...", "Question 11: ...", "Question 12: ...", "Question 13: ...", "Question 14: ...", "Question 15: ...", "Question 16: ...", "Question 17: ...", "Question 18: ...", "Question 19: ...", "Question 20: ..."}
		Dim indices() As Integer = Enumerable.Range(0, questions.Length - 1).OrderBy(Function(i) r.Next()).Take(count ).ToArray()

        For i = 0 To count -1 
            Response.Write (questions(indices(i)) + "<br />")
        Next
		
    End Sub

DEMO

Answer 2

User-1578974752 posted

Hi Vahid bakkhi

How can I implement this inside a Listview control .Where questions are retrieved from the database.Thanks

<asp:Datapager ID="dtpgr" runat="server" pagedcontrolid="ListView1" Pagesize="5">

<Fields>

<asp:NumericPagerField ButtonCount="5"

NumericButtonCssClass="numeric_button"

CurrentPageLabelCssClass="current_page"

NextPreviousButtonCssClass="next_button" />

</Fields>

</asp:DataPager>

　

<asp:ListView ID="ListView1" runat="server" DataSourceID="SqlDataSource2">

<itemtemplate>

<div>

<td align="left"><%#DataBinder.Eval(Container.DataItem, "Question") %></td>

</div>

<table>

<tr style="background-color:White;">

<td align="right"><img src="images/Dot.gif"/></td>

<td align="center"><asp:RadioButton ID="rad1" GroupName="Group1" runat="server" /></td>

<td align="left"><%#DataBinder.Eval(Container.DataItem, "Option1") %></td>

<td align="left"><asp:RadioButton ID="rad2" GroupName="Group1" runat="server" OnSelectedIndexChanged="btnSave_Click" /></td>

<td align="left"><%#DataBinder.Eval(Container.DataItem, "Option2") %></td>

<td align="center"><asp:RadioButton ID="rad3" GroupName="Group1" runat="server" /></td>

<td align="left"><%#DataBinder.Eval(Container.DataItem, "Option3") %></td>

<td align="center"><asp:RadioButton ID="rad4" GroupName="Group1" runat="server" /></td>

<td align="left"><%#DataBinder.Eval(Container.DataItem, "Option4") %></td>

<td>

</td>

</table>

</itemtemplate>

</asp:ListView>

<asp:SqlDataSource ID="SqlDataSource2" runat="server" ConnectionString="<%$ ConnectionStrings:QSCTestConnectionString %>" SelectCommand="SELECT [Question], [Option1], [Option2], [Option3], [Option4], [Option5] FROM [QuestionDetail]"></asp:SqlDataSource>

<asp:Button ID="Button1" runat="server" Text="Button" />

 

Answer 3

User-369506445 posted

first select your data from <g class="gr_ gr_15 gr-alert gr_gramm gr_inline_cards gr_run_anim Style multiReplace" id="15" data-gr-id="15"><g class="gr_ gr_8 gr-alert gr_spell gr_inline_cards gr_disable_anim_appear ContextualSpelling ins-del multiReplace" id="8" data-gr-id="8">databse</g> ,</g> then store then into <g class="gr_ gr_12 gr-alert gr_gramm gr_inline_cards gr_run_anim Grammar multiReplace" id="12" data-gr-id="12">a array</g> and <g class="gr_ gr_13 gr-alert gr_gramm gr_inline_cards gr_run_anim Punctuation only-ins replaceWithoutSep" id="13" data-gr-id="13">finally</g> you can use it like the last sample 

please follow step by step

<g class="gr_ gr_14 gr-alert gr_gramm gr_inline_cards gr_run_anim Punctuation only-ins replaceWithoutSep" id="14" data-gr-id="14">first</g> create a class called MYItems

Public Class MYItems
        Private _question As String
        Private _option1 As String
         Private _option2 As String
         Private _option3 As String
         Private _option4 As String
         Private _option5 As String


        Public Property Option1() As String
            Get
                Return _option1
            End Get
            Set(ByVal value As String)
                _option1 = value
            End Set
        End Property

        Public Property Option2() As String
            Get
                Return _option2
            End Get
            Set(ByVal value As String)
                _option2 = value
            End Set
        End Property

        Public Property Option3() As String
            Get
                Return _option3
            End Get
            Set(ByVal value As String)
                _option3 = value
            End Set
        End Property

        Public Property Option4() As String
            Get
                Return _option4
            End Get
            Set(ByVal value As String)
                _option4 = value
            End Set
        End Property

        Public Property Option5() As String
            Get
                Return _option5
            End Get
            Set(ByVal value As String)
                _option5 = value
            End Set
        End Property

        Public Property Question() As String
            Get
                Return _question
            End Get
            Set(ByVal value As String)
                _question = value
            End Set
        End Property

    End Class

Then fetch from <g class="gr_ gr_9 gr-alert gr_gramm gr_inline_cards gr_run_anim Grammar only-ins replaceWithoutSep" id="9" data-gr-id="9">database</g>

  Private Function fetchFromDB() As List(Of MYItems)

        Dim list As New List(Of MYItems )


        Dim conn As New SqlConnection
        If conn.State = ConnectionState.Closed Then
            conn.ConnectionString = ("Data Source=.;Initial Catalog=Your Database Name;trusted_connection=true")
        End If

        Try
            conn.Open()
            Dim sqlquery As String = "SELECT [Question], [Option1], [Option2], [Option3], [Option4], [Option5] FROM [QuestionDetail] "
            Dim data As SqlDataReader
            Dim adapter As New SqlDataAdapter
            Dim parameter As New SqlParameter
            Dim command As SqlCommand = New SqlCommand(sqlquery, conn)

            command.Connection = conn
            adapter.SelectCommand = command
            data = command.ExecuteReader()
            While data.Read
                If data.HasRows = True Then
                    Dim obj As MYItems =New MYItems
                    obj.Question = data (0)
                    obj.Option1  = data (1)
                    obj.Option2  = data (2)
                    obj.Option2  = data (3)
                    obj.Option3  = data (4)
                    obj.Option4  = data (5)
                    obj.Option5  = data (6)
                    list.Add(obj)
                End If
            End While

            Return list 
        Catch ex As Exception
            Return list 
        End Try
    End Function

finally bind to your control

Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim count As Integer = 5
        Dim questions As List(Of MYItems ) = fetchFromDB ()
		Dim indices() As Integer = Enumerable.Range(0, questions.Count  - 1).OrderBy(Function(i) r.Next()).Take(count ).ToArray()

        Dim model = New List(Of MYItems) 
        For i = 0 To count -1 
            model.Add(questions(indices(i))) 
        Next

        ListView1.DataSource = model 
        ListView1.DataBind()  
		
    End Sub

Answer 4

User-1578974752 posted

Dim indices() As Integer = Enumerable.Range(0, questions.Count - 1).OrderBy(Function(i) r.Next()).Take(count).ToArray()

here r is not declared.It may be in accessible due to its protection level message is showing.Tried to declare as integer..still error

Answer 5

User-369506445 posted

Private r As New Random()

Answer 6

User-2015242085 posted

Hi

If questions are stored in SQL you can like this:

SELECT TOP 10 QuestionId FROM Questions ORDER BY NEWID()

Answer 7

User-1578974752 posted

Working fine . But I have 3 pages in the listview.Each page will contain 5 questions.so when I do as below, some times the questions in page 1 in repeating in Page2.How can I solve that.Thanks

<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:TestConnectionString %>" SelectCommand="SELECT TOP 15 [Question],[CorrectAnswer],[Option1], [Option2], [Option3], [Option4], [Option5], [QuestDetailID], [QuestionMasterID] FROM [QuestionDetail] WHERE ([QuestionMasterID] = @QuestionMasterID) ORDER BY NEWID()">