Example Application: Elementary Addition

Description

This small application can help you check your ability to perform simple additions of natural numbers (integers between 0 and 99).

Practical Learning: Introducing Text Boxes

1. Create a Window Forms Application named ElementaryAddition2
2. Design the form as follows:
    

   

   Control	Text	Name	TextAlign	Font	Additional Properties
   Label	00	lblOperand1	Center	Name: Tahoma Size:   48 Bold:   True	AutoSize: True ForeColor: Blue
   Label	+		Center	Name: Arial Size:   50 Bold:   True	AutoSize: True ForeColor: Maroon
   Label	00	lblOperand2	Center	Name: Tahoma Size:   48 Bold:   True	AutoSize: True ForeColor: Blue
   Label	=		Center	Name: Arial Size:   50 Bold:   True	AutoSize: True ForeColor: Green
   TextBox	000	txtResult	Center	Name: Tahoma Size:   48 Bold:   True
   Label	New Operation	lblNewOperation	Center	Name: Tahoma, Size: 28 Bold: True	AutoSize: True BorderStyle: Fixed3D ForeColor: White BackColor:Maroon
   Label	Check	lblCheckAnswer	Center	Name: Tahoma, Size: 28 Bold: True	AutoSize: True BorderStyle: Fixed3D ForeColor: White BackColor:Maroon
   Label	Quit	lblQuit	Center	Name: Tahoma, Size: 28 Bold: True	AutoSize: True BorderStyle: FixedSingle

3. Double-click the New Operation label and implement its event as follows:
   

   private void lblNewOperation_Click(object sender, EventArgs e)
   {
           int operand1;
           int operand2;
   
           Random rnd = new Random();
   
           operand1 = rnd.Next(99);
           operand2 = rnd.Next(99);
           int result = operand1 + operand2;
   
           lblOperand1.Text = operand1.ToString();
           lblOperand2.Text = operand2.ToString();
           txtResult.Text   = "";
           txtResult.Focus();
   }

4. Return to the form and double-click the Check label
5. Implement its event as follows:
   

   private void lblCheckAnswer_Click(object sender, EventArgs e)
   {
       int Operand1 = 0;
       int Operand2 = 0;
       int Result = 0;
   
           try
           {
                   Operand1 = int.Parse(lblOperand1.Text);
           }
           catch (FormatException)
           {
                   MessageBox.Show("Invalid Value");
           }
   
           try
           {
                   Operand2 = int.Parse(lblOperand2.Text);
           }
           catch (FormatException)
           {
                   MessageBox.Show("Invalid Value");
           }
   
           try
           {
                   Result = int.Parse(txtResult.Text);
           }
           catch (FormatException)
           {
                   MessageBox.Show("Invalid Answer");
           }
   
           if (Result == (Operand1 + Operand2))
                   MessageBox.Show("WOW - Good Answer");
           else
                   MessageBox.Show("PSSST - Wrong Answer");
   
           lblNewOperation_Click(sender, e);
   }

6. Return to the form and double-click Quit
7. Implement its event as follows:
   

   private void lblQuit_Click(object sender, EventArgs e)
   {
               Close();
   }

8. Execute the application and test it
9. Click the Close button to close the form and return to your programming environment