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namespace _103303067_0504_01
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
double no1, no2, sum ;
no1 = Convert.ToInt32(textBox1.Text);
no2 = Convert.ToInt32(textBox2.Text);
if (comboBox1.SelectedIndex == 0)
{
sum = no1 + no2;
textBox3.Text = Convert.ToString(sum);
}
if (comboBox1.SelectedIndex == 1)
{
sum = no1 - no2;
textBox3.Text = Convert.ToString(sum);
}
if (comboBox1.SelectedIndex == 2)
{
sum = no1 * no2;
textBox3.Text = Convert.ToString(sum);
}
if (comboBox1.SelectedIndex == 3)
{

if (no2 == 0)
{
textBox3.Text = "無解";
DialogResult = MessageBox.Show("除數不可為零", "注意", MessageBoxButtons.OK);

}
else
{
sum = no1 / no2;
textBox3.Text = Convert.ToString(sum);
}

}


}
}
}