57 lines
1.5 KiB
C#
57 lines
1.5 KiB
C#
using System;
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using System.Collections.Generic;
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using System.ComponentModel;
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using System.Data;
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using System.Drawing;
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using System.Linq;
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using System.Text;
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using System.Windows.Forms;
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namespace Optional_Argument
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{
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public partial class Form1 : Form
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{
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public Form1()
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{
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InitializeComponent();
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}
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// The ShowTax method displays the sales tax for an item.
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private void ShowTax(decimal price, decimal taxRate = 0.07m)
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{
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// Calculate the tax.
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decimal tax = price * taxRate;
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// Display the tax.
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MessageBox.Show("The tax is " + tax.ToString("c"));
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}
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private void exitButton_Click(object sender, EventArgs e)
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{
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// Close the form.
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this.Close();
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}
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private void showTaxButton_Click(object sender, EventArgs e)
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{
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// Variable to hold the item's price.
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decimal itemPrice;
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// Get the item's price.
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if (decimal.TryParse(priceTextBox.Text, out itemPrice))
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{
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// Show the tax at the default tax rate.
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ShowTax(itemPrice);
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// Show the tax at 8 percent.
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ShowTax(itemPrice, 0.08m);
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}
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else
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{
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// Error message for invalid price
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MessageBox.Show("Invalid value for price.");
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}
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}
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}
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}
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