手順 7: 乗算問題と除算問題の追加Step 7: Add Multiplication and Division Problems

このチュートリアルの第 7 部では、乗算問題と除算問題を追加しますが、まず変更方法について考えてみます。In the seventh part of this tutorial, you'll add multiplication and division problems, but first think about how to make that change. 最初の手順は、値を格納することです。Consider the initial step, which involves storing values.

乗算問題と除算問題を追加するにはTo add multiplication and division problems

  1. さらに 4 つの整数変数をフォームに追加します。Add four more integer variables to the form.

    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. 以前に実行したように、StartTheQuiz() メソッドを変更して、乗算問題と除算問題に乱数を入力するようにします。As you did before, modify the StartTheQuiz() method to fill in random numbers for the multiplication and division problems.

    ''' <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. 乗算問題と除算問題についても確認するように CheckTheAnswer() メソッドを変更します。Modify the CheckTheAnswer() method so that it also checks the multiplication and division problems.

    ''' <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;
    }
    

    乗算記号 (×) と除算記号 (÷) はキーボードから簡単に入力できないため、Visual C# および Visual Basic では、乗算にはアスタリスク ()、除算にはスラッシュ記号 (/) を使用します。You can't easily enter the multiplication sign (×) and the division sign (÷) using the keyboard, so Visual C# and Visual Basic accept an asterisk () for multiplication and a slash mark (/) for division.

  4. タイマーの Tick イベント ハンドラーの最後の部分を、残り時間がなくなったら正しい解答を表示するように変更します。Change the last part of the timer's Tick event handler so that it fills in the correct answer when time runs out.

    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. プログラムを保存し、実行します。Save and run your program.

    次の図に示すように、クイズの受け手はクイズを完了するためには 4 つの問題に答える必要があります。Quiz takers must answer four problems to complete the quiz, as the following illustration shows.

    4 つの問題がある計算クイズMath quiz with four problems
    4 つの問題がある計算クイズMath quiz with four problems

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