Schritt 7: Hinzufügen von Multiplikations- und Divisionsaufgaben

Im siebenten Teil dieses Lernprogramms fügen Sie Multiplikations- und Divisionsaufgaben hinzu. Zunächst müssen Sie aber überlegen, wie diese Änderung vorgenommen wird.Überlegen Sie sich den ersten Schritt, der das Speichern von Werten einschließt.

So fügen Sie Multiplikations- und Divisionsaufgaben hinzu

  1. Fügen Sie dem Formular vier Ganzzahlvariablen hinzu.

    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. Ändern Sie wie zuvor die StartTheQuiz()-Methode, damit die Multiplikations- und Divisionsaufgaben mit Zufallszahlen ausgefüllt werden.

    ''' <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. Ändern Sie die CheckTheAnswer()-Methode, damit auch die Multiplikations- und Divisionsaufgaben überprüft werden.

    ''' <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;
}

    Da es keine einfache Möglichkeit gibt, das Multiplikationszeichen (×) und das Divisionszeichen (÷) mit der Tastatur einzugeben, wird in Visual C# und Visual Basic ein Sternchen (*) für Multiplikation und ein Schrägstrich (/) für Division akzeptiert.

  4. Ändern Sie den letzten Teil des Tick-Ereignishandlers des Zeitgebers, damit die richtige Antwort ausgegeben wird, wenn die Zeit abgelaufen ist.

    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. Speichern Sie das Programm, und führen Sie es aus.

    Die Quizteilnehmer müssen vier Aufgaben beantworten, um das Quiz abzuschließen. Dies ist in der folgenden Abbildung veranschaulicht.

    Mathequiz mit vier Aufgaben

    Mathetest mit vier Aufgaben

So fahren Sie fort oder überprüfen die Angaben

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