private void button1_Click(object sender, EventArgs e)
{
//this.label1.Text = this.textBox1.Text + comboBox1.SelectedItem + this.textBox2.Text;
String str = comboBox1.GetItemText(comboBox1.SelectedItem);
Operation oper = OperationFactory.createOperation(str);
try
{
oper.num1 = Convert.ToDouble(this.textBox1.Text);
oper.num2 = Convert.ToDouble(this.textBox2.Text);
}catch (Exception)
{
throw;
}
double result = oper.getResult();
this.label1.Text = Convert.ToString("result =" + result);
}