Passaggio 7: aggiungere problemi di moltiplicazione e divisione

Nella settima parte di questa esercitazione si aggiungeranno i problemi di moltiplicazione e divisione, ma prima di procedere vedere come effettuare questa modifica.Considerare il passaggio iniziale, che comporta l'archiviazione dei valori.

Per aggiungere problemi di moltiplicazione e divisione

  1. Aggiungere altre quattro variabili di tipo Integer al modulo.

    Public Class Form1

    ' Create a Random object called randomizer  
    ' to generate random numbers. 
    Private randomizer As New Random

    ' These integer variables store the numbers  
    ' for the addition problem.  
    Private addend1 As Integer 
    Private addend2 As Integer 


    ' These integer variables store the numbers  
    ' for the subtraction problem.  
    Private minuend As Integer 
    Private subtrahend As Integer 

    ' These integer variables store the numbers  
    ' for the multiplication problem.  
    Private multiplicand As Integer 
    Private multiplier As Integer 

    ' These integer variables store the numbers  
    ' for the division problem.  
    Private dividend As Integer 
    Private divisor As Integer 

    ' This integer variable keeps track of the  
    ' remaining time. 
    Private timeLeft As Integer

    public partial class Form1 : Form
{
    // Create a Random object called randomizer  
    // to generate random numbers.
    Random randomizer = new Random();

    // These integer variables store the numbers  
    // for the addition problem.  
    int addend1;
    int addend2;

    // These integer variables store the numbers  
    // for the subtraction problem.  
    int minuend;
    int subtrahend;

    // These integer variables store the numbers  
    // for the multiplication problem.  
    int multiplicand;
    int multiplier;

    // These integer variables store the numbers  
    // for the division problem.  
    int dividend;
    int divisor;

    // This integer variable keeps track of the  
    // remaining time. 
    int timeLeft;

  2. Come in precedenza, modificare il metodo StartTheQuiz() per inserire numeri casuali per i problemi di moltiplicazione e divisione.

    ''' <summary> 
''' Start the quiz by filling in all of the problem  
''' values and starting the timer.  
''' </summary> 
''' <remarks></remarks> 
Public Sub StartTheQuiz()

    ' Fill in the addition problem. 
    ' Generate two random numbers to add. 
    ' Store the values in the variables 'addend1' and 'addend2'.
    addend1 = randomizer.Next(51)
    addend2 = randomizer.Next(51)

    ' Convert the two randomly generated numbers 
    ' into strings so that they can be displayed 
    ' in the label controls.
    plusLeftLabel.Text = addend1.ToString()
    plusRightLabel.Text = addend2.ToString()

    ' 'sum' is the name of the NumericUpDown control. 
    ' This step makes sure its value is zero before 
    ' adding any values to it.
    sum.Value = 0

    ' Fill in the subtraction problem.
    minuend = randomizer.Next(1, 101)
    subtrahend = randomizer.Next(1, minuend)
    minusLeftLabel.Text = minuend.ToString()
    minusRightLabel.Text = subtrahend.ToString()
    difference.Value = 0

    ' Fill in the multiplication problem.
    multiplicand = randomizer.Next(2, 11)
    multiplier = randomizer.Next(2, 11)
    timesLeftLabel.Text = multiplicand.ToString()
    timesRightLabel.Text = multiplier.ToString()
    product.Value = 0

    ' Fill in the division problem.
    divisor = randomizer.Next(2, 11)
    Dim temporaryQuotient As Integer = randomizer.Next(2, 11)
    dividend = divisor * temporaryQuotient
    dividedLeftLabel.Text = dividend.ToString()
    dividedRightLabel.Text = divisor.ToString()
    quotient.Value = 0

    ' Start the timer.
    timeLeft = 30
    timeLabel.Text = "30 seconds"
    Timer1.Start()

End Sub

    /// <summary> 
/// Start the quiz by filling in all of the problem  
/// values and starting the timer.  
/// </summary> 
public void StartTheQuiz()
{
    // Fill in the addition problem. 
    // Generate two random numbers to add. 
    // Store the values in the variables 'addend1' and 'addend2'.
    addend1 = randomizer.Next(51);
    addend2 = randomizer.Next(51);

    // Convert the two randomly generated numbers 
    // into strings so that they can be displayed 
    // in the label controls.
    plusLeftLabel.Text = addend1.ToString();
    plusRightLabel.Text = addend2.ToString();

    // 'sum' is the name of the NumericUpDown control. 
    // This step makes sure its value is zero before 
    // adding any values to it.
    sum.Value = 0;

    // Fill in the subtraction problem.
    minuend = randomizer.Next(1, 101);
    subtrahend = randomizer.Next(1, minuend);
    minusLeftLabel.Text = minuend.ToString();
    minusRightLabel.Text = subtrahend.ToString();
    difference.Value = 0;

    // Fill in the multiplication problem.
    multiplicand = randomizer.Next(2, 11);
    multiplier = randomizer.Next(2, 11);
    timesLeftLabel.Text = multiplicand.ToString();
    timesRightLabel.Text = multiplier.ToString();
    product.Value = 0;

    // Fill in the division problem.
    divisor = randomizer.Next(2, 11);
    int temporaryQuotient = randomizer.Next(2, 11);
    dividend = divisor * temporaryQuotient;
    dividedLeftLabel.Text = dividend.ToString();
    dividedRightLabel.Text = divisor.ToString();
    quotient.Value = 0;

    // Start the timer.
    timeLeft = 30;
    timeLabel.Text = "30 seconds"; 
    timer1.Start();
}

  3. Modificare il metodo CheckTheAnswer() in modo che controlli anche i problemi di moltiplicazione e divisione.

    ''' <summary> 
''' Check the answers to see if the user got everything right. 
''' </summary> 
''' <returns>True if the answer's correct, false otherwise.</returns> 
''' <remarks></remarks> 
Public Function CheckTheAnswer() As Boolean 

    If addend1 + addend2 = sum.Value AndAlso 
       minuend - subtrahend = difference.Value AndAlso 
       multiplicand * multiplier = product.Value AndAlso 
       dividend / divisor = quotient.Value Then 

        Return True 
    Else 
        Return False 
    End If 

End Function

    /// <summary> 
/// Check the answers to see if the user got everything right. 
/// </summary> 
/// <returns>True if the answer's correct, false otherwise.</returns> 
private bool CheckTheAnswer()
{
    if ((addend1 + addend2 == sum.Value)
        && (minuend - subtrahend == difference.Value)
        && (multiplicand * multiplier == product.Value)
        && (dividend / divisor == quotient.Value))
        return true;
    else 
        return false;
}

    Poiché non esiste un modo semplice di immettere il segno di moltiplicazione (×) e il segno di divisione (÷) utilizzando la tastiera, in Visual C# e Visual Basic si utilizza un asterisco (*) per la moltiplicazione e una barra (/) per la divisione.

  4. Modificare l'ultima parte del gestore dell'evento Tick del timer in modo che inserisca la risposta corretta alla scadenza del tempo.

    Else 
    ' If the user ran out of time, stop the timer, show 
    ' a MessageBox, and fill in the answers.
    Timer1.Stop()
    timeLabel.Text = "Time's up!"
    MessageBox.Show("You didn't finish in time.", "Sorry!")
    sum.Value = addend1 + addend2
    difference.Value = minuend - subtrahend
    product.Value = multiplicand * multiplier
    quotient.Value = dividend / divisor
    startButton.Enabled = True 
End If

    else
{
    // If the user ran out of time, stop the timer, show  
    // a MessageBox, and fill in the answers.
    timer1.Stop();
    timeLabel.Text = "Time's up!";
    MessageBox.Show("You didn't finish in time.", "Sorry");
    sum.Value = addend1 + addend2;
    difference.Value = minuend - subtrahend;
    product.Value = multiplicand * multiplier;
    quotient.Value = dividend / divisor;
    startButton.Enabled = true;
}

  5. Salvare ed eseguire il programma.

    Gli esecutori del quiz devono risolvere quattro problemi per completare il quiz, come illustrato di seguito.

    Quiz matematico con quattro problemi

    Quiz matematico con quattro problemi

Per continuare o rivedere l'esercitazione

  • Last updated on