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Generate Dropdownlists dynamically and bind data from datatable or dataadapter methods

ee-itpro
ee-itpro asked
on
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Last Modified: 2012-05-07
Hi,
     I'm  not much experienced with asp.net development.  I have a database for a kind of quiz application, answers to which are then processed through logic to generate or determine a plan for the user.

I have two tables in the database 1)Questions  table with Qid(P key), Q description etc.

2)QuestionAns table which contains all the answer options for every question in the question table.   Columns are QueAnsId(P. Key),Qid(foreign key), Answers(all answers options for every question).

I created two datasets for each of these tables using the configuration wizards. 1)QuesDS,
2)AnsDS

On their respective tableAdapters, i have written methods GetQuestions(), GetAnswersByQuesId(Qid)containg respective sql queries.

What i want to achieve is,  for each question  displayed , a dropdownlist with all the answer options for that question be displayed. Then a question again and A dropdownlist again and so on.  The answer dropdownlists should be  generated dynamically based on number of questions  in the question table. I can get the questions to print but not the answers list.

My questions are:

1)Is a Dataset solution appropriate for this or should i be using a datareader?
2)Am i on the right track  or is this the appropriate way of what i am trying to achieve?
3)Get the dropdownlists to work.


Code for this follows below:

using.........default namespaces.......
using QuesDSTableAdapters;
using AnsDSTableAdapters;


public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {


        QuesDSTableAdapters.QuestionTableAdapter questionsAdapter = new
 QuesDSTableAdapters.QuestionTableAdapter();

        QuesDS.QuestionDataTable questions;

        questions = questionsAdapter.GetQuestions();



        AnsDSTableAdapters.QueAnsTableAdapter queansAdapter = new
 AnsDSTableAdapters.QueAnsTableAdapter();

 AnsDS.QueAnsDataTable answer;

               // AnsDS.QueAnsDataTable queans;


foreach (QuesDS.QuestionRow quesRow in questions)
        {


            Response.Write("Question: " + quesRow.Que + "<br />");

            answer = queansAdapter.GetAnswersByQuestionId(quesRow.QID);

            DropDownList ddl = new DropDownList() ;

            // ddl.DataSource = queansAdapter.GetAnswersByQuestionId(Convert.ToInt32(quesRow.QID));

           
ddl.DataSource = answer;

           // DropDownList1.Items.Add(Convert.ToString(answer.Columns ["Answer"]));

ddl.DataTextField  = "Answer";

            ddl.DataBind();
           


        }

    }

Comment
Watch Question

Commented:
Are you getting anything for the answer DDL?

Author

Commented:
Didn't understand that.

Commented:
Are you getting anything to show in the Drop Down List for the answers or does it just remain blank?

Author

Commented:
Remains blank and shows after the two questions that i have currently in  question table.  It should show like ques and then ans nad then ques again and ans again.

Commented:
You mean the control itself shows after the two questions are printed? if so you need to add the control to the from within the foreach loop

Author

Commented:
Yes after the two questions are printed.  

Commented:
Where is the line where you adding the control to the page?

Author

Commented:
i just have it in design view.... how do we add it the code?

Author

Commented:
i added it just now like this :

DropDownList ddl=new DropDownlist();

form.controls.add(ddl);


Now it shows the lists but there are 3 instead of 2 for 2 questions and they all show in a horizontal line and after the printed questions.

Commented:
you can add this between each control and each question to break the line:

form.controls.Add(new LiteralControl("<br/>"));

As to it adding it 3 times it must be something in the loop that makes it run 3 times instead ok.

Author

Commented:
the dropdownlists still appear after the questions

Commented:
can you post your complete code again pls

Author

Commented:
public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {


        QuesDSTableAdapters.QuestionTableAdapter questionsAdapter = new
 QuesDSTableAdapters.QuestionTableAdapter();
        QuesDS.QuestionDataTable questions;

        questions = questionsAdapter.GetQuestions();



        AnsDSTableAdapters.QueAnsTableAdapter queansAdapter = new
 AnsDSTableAdapters.QueAnsTableAdapter();

        AnsDS.QueAnsDataTable answer;

       

       // AnsDS.QueAnsDataTable queans;

       




        foreach (QuesDS.QuestionRow quesRow in questions)
        {


            Response.Write("Question: " + quesRow.Que + "<br />");



           answer = queansAdapter.GetAnswersByQuestionId(quesRow.QID);

           Form.Controls.Add(new LiteralControl("<br/>"));

            DropDownList ddl = new DropDownList();


           


            Form.Controls.Add(ddl);

            // ddl.DataSource = queansAdapter.GetAnswersByQuestionId(Convert.ToInt32(quesRow.QID));

            ddl.DataSource = answer;

           // DropDownList1.Items.Add(Convert.ToString(answer.Columns ["Answer"]));
            ddl.DataTextField  = "Answer";
            ddl.DataBind();

           
           
        }

    }
    protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {

    }
}

Commented:
i still dont see where are you adding the control to the page?

Author

Commented:
after i create the dropdownlist object, then i write

form.control.add(ddl),


where ddl is the dropdownlisty object i created .
Commented:
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Author

Commented:
i added form.control.aa(new literal control........)  in between  ques and ans and also twice before the end of foreach loop. So now it displays better.  But there's still a empty drop downlist that appears  just before the first question.


 foreach (PLabDS.QuestionRow quesRow in questions)
        {


            //Response.Write("Question: " + quesRow.Que + "<br />");



           //answer = queansAdapter.GetAnswersByQuestionId(quesRow.QID);

           Form.Controls.Add(new LiteralControl(quesRow.Que));

           answer = queansAdapter.GetAnswersByQuestionId(quesRow.QID);

            DropDownList ddl = new DropDownList();


            Form.Controls.Add(new LiteralControl("<br>"));


            Form.Controls.Add(ddl);

            // ddl.DataSource = queansAdapter.GetAnswersByQuestionId(Convert.ToInt32(quesRow.QID));

            ddl.DataSource = answer;

           // DropDownList1.Items.Add(Convert.ToString(answer.Columns ["Answer"]));
            ddl.DataTextField  = "Answer";
            ddl.DataBind();

            Form.Controls.Add(new LiteralControl("<br>"));

            Form.Controls.Add(new LiteralControl("<br>"));
           
        }

Author

Commented:
deleted the list control from design view . it's working fine now...


i'll accept the solution.



can you just tell me if i am using the right approach (datasets  instead of datareader for this particular scenario)?

Author

Commented:
deleted the list control from design view . it's working fine now...


i'll accept the solution.



can you just tell me if i am using the right approach (datasets  instead of datareader for this particular scenario)?

Commented:
Yes a dataset or a datatables are just fine.
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