VB.NET - Windows App: Loop / MsgBox help needed

[perkykoala]

I apologize in advance for being REALLY detailed/verbose. It's the result of staring/tweaking code for too long.

Using VB 2005:

I need to design a multiple choice test (unfortunately, I can't use radio buttons).

How it works...
Pre-1) File consists of the following format:
Question 1
Choice 1
Choice 2
Choice 3
Choice 4
Correct Choice
Question 2, etc.

1) I get my input from the file described above file (and display it)
2) The user must type the answer (letter) in a text box
3) The user clicks a button (to submit the answer), and the appropriate action is taken:
Correct -> MsgBox with correct message -> go to next question
Incorrect -> MsgBox with incorrect message -> go to next question
Invalid answer -> MsgBox with invalid message -> try again (until a valid message is received)

The first set of questions come in when the form loads -- that's working fine.

User = me

I type in an answer, and the MsgBox comes up -- that's working fine.

Problem: I click OK in the MsgBox...
a) For *all* answers, the question advances -- it should only do that for correct and incorrect answers (but not for invalid answers).
b) The program doesn't wait for me to put in the answer to the next question, so it just comes up as a blank, which is an invalid answer. (Go to problem a.) I click OK, and it repeats until the file ends.

How can I solve these issues? I know that they need to have another loop or two in there somewhere, but it seems like I've tried every loop placement that there is and none work.

Here is my code for this private sub activated by clicking the button, and you'll see where I need for it to "wait" for input:

Private Sub cmdSubmit_Click(...) Handles cmdSubmit.Click
        Dim sr As IO.StreamReader = IO.File.OpenText("QUESTIONS.TXT")
        Dim question, choicea, choiceb, choicec, choiced, realanswer As String
        Dim useranswer As String = ""
        Dim score As Double
        Do While sr.Peek <> -1
            txtQuestion.Clear()
            lstChoices.Items.Clear()
            question = sr.ReadLine
            choicea = sr.ReadLine
            choiceb = sr.ReadLine
            choicec = sr.ReadLine
            choiced = sr.ReadLine
            txtQuestion.Text = question
            With lstChoices.Items
                .Add(choicea)
                .Add(choiceb)
                .Add(choicec)
                .Add(choiced)
            End With
            realanswer = sr.ReadLine
            useranswer = txtAnswer.Text.ToLower() ///If there is no input, wait until there is some input!!!
            If useranswer = realanswer Then
                MsgBox("Good job!", 0, "Correct")
                score += 1
                txtAnswer.Clear()
            ElseIf (useranswer = "a") Or (useranswer = "b") Or (useranswer = "c") Or (useranswer = "d") Then
                MsgBox("Sorry, the answer was " & realanswer & ".", 0, "Incorrect")
                txtAnswer.Clear()
            Else
                MsgBox("That is not a valid choice.  Please try again", 0, "Invalid Choice")
                txtAnswer.Clear()
                txtAnswer.Focus()
            End If
        Loop
        sr.Close()
        txtAnswer.Enabled = False
        cmdSubmit.Enabled = False
        lblInstructions.Focus()
        txtScore.Text = "Your score is " & score & "."
    End Sub

Thanks so much in advance!!

[Shashi Sadasivan]

Hi,
i think this is a windows application!

why is all your code in the submit button?

according to this code...
when the program starts, there should be nothing regarding the queastions appearing.

when the user clicks the submit button the question file will be read, and then the code will run, andit will not wait for any user input until it has scrolled through alll the questions in the file!

So the conclusion is that when you read one question set from the file, you stop until the submit button is pressed

when the submit bbuton is pressed, check if the answer is right
if right, then advance reading the next question, else do nothing.

[perkykoala]

Okay, gotcha -- I'll try it out. It's all in one procedure now, but once I get it working properly, then I'll divide it up into sub procedures. Thanks for your help, Shashi!

Hi,
i think this is a windows application!

why is all your code in the submit button?

according to this code...
when the program starts, there should be nothing regarding the queastions appearing.

when the user clicks the submit button the question file will be read, and then the code will run, andit will not wait for any user input until it has scrolled through alll the questions in the file!

So the conclusion is that when you read one question set from the file, you stop until the submit button is pressed

when the submit bbuton is pressed, check if the answer is right
if right, then advance reading the next question, else do nothing.