private void btnCalculate_Click(object sender, EventArgs e)
{
if (this.txtPrice.Text.Trim() == "" || this.txtNumber.Text.Trim() == "")
{
MessageBox.Show("Please input the price and number!");
return;
}
CashContext cashContext;
double cashFinal = 0;
switch (Convert.ToInt32(this.cboDiscount.SelectedValue))
{
case 1:
cashContext = new CashContext(new CashNoDiscount());
cashFinal = cashContext.GetCashResultFinal(Convert.ToDouble(this.txtPrice.Text.Trim()),
Convert.ToDouble(this.txtNumber.Text.Trim()));
break;
case 2:
cashContext = new CashContext(new CashPercent());
cashFinal = cashContext.GetCashResultFinal(Convert.ToDouble(this.txtPrice.Text.Trim()),
Convert.ToDouble(this.txtNumber.Text.Trim()));
break;
case 3:
cashContext = new CashContext(new CashReturn());
cashFinal = cashContext.GetCashResultFinal(Convert.ToDouble(this.txtPrice.Text.Trim()),
Convert.ToDouble(this.txtNumber.Text.Trim()));
break;
}
this.txtResult.Text = "Total : " + cashFinal.ToString();
}
// 策略模式 定义一系列算法，把它们一个个封装起来，并且使它们之间可互相替换，从而让算法可以独立于使用它的用户而变化。
static void Strategy()
{
CashNormal cashNormal = new CashNormal();
CashContext contextNormal = new CashContext(cashNormal);
Console.WriteLine("700:" + contextNormal.GetResult(700));
CashRebate cashRebate = new CashRebate("0.8");
CashContext contextRebate = new CashContext(cashRebate);
Console.WriteLine("700打8折:" + contextRebate.GetResult(700));
CashReturn cashReturn = new CashReturn("300", "100");
CashContext contextReturn = new CashContext(cashReturn);
Console.WriteLine("700满300减100:" + contextReturn.GetResult(700));
}
