private void btnOK_Click(object sender, RoutedEventArgs e)
{
// 根据下拉选择框，将相应的算法类型字符串传入CashContext的对象中
CashContext cc = new CashContext(cbxType.SelectedItem.ToString());
double totalPrices = 0d;
totalPrices = cc.GetResult(Convert.ToDouble(txtPrice.Text) * Convert.ToDouble(txtNum.Text));
total = total + totalPrices;
lbxList.Items.Add($"单价：{txtPrice.Text} 数量：{txtNum.Text} {cbxType.SelectedItem} 合计：{totalPrices}");
lblResult.Text = total.ToString();
}
static void Main(string[] args)
{
CashContext context;
// 由于实例化不同的策略，所以最终在调用context.ContextInterface();时，所获得的结果就不尽相同
context = new CashContext(new ConcreteStrategyA());
context.ContextInterface();
context = new CashContext(new ConcreteStrategyB());
context.ContextInterface();
context = new CashContext(new ConcreteStrategyC());
context.ContextInterface();
}
