//数字键监听
private void btnNum_Click(object sender,EventArgs e)
{
if(sender is Button)
{
Button btn = (Button)sender;
if (!stop)
{
//得到当前按键数字，追加
show.Text += btn.Text;
}
else
{
stop = false;//完成了一次算式运算之后重新初始化
show.Text = btn.Text;//清空并填充当前数据
handler = null;//委托方法列表清空
}
}
}
static void Main(string[] args)
{
Calcuate calc = (a, b) => a + b;
Console.WriteLine($"3 + 4 = " + calc(3, 4));
}
//运算符监听
private void btnOperation_Click(object sender, EventArgs e)
{
Button btn = (Button)sender;
if (!stop)
{
//追加运算符
show.Text += btn.Text;
//记录当前算式运算符
operation = btn.Text;
//委托相应的运算方法
switch (operation)
{
case "+":
handler += math.Add;
break;
case "-":
handler += math.Sub;
break;
case "*":
handler += math.Mul;
break;
case "/":
handler += math.Div;
break;
}
}
else
{
//还没输入过数字就输入运算符
MessageBox.Show("您还没输入第一操作数哦！");
}
}