C# 演唱会门票，简单的 switch、case 和 if-else

Question

Program Specification: The purpose of this application will be to calculate the cost for concert tickets. The individual ticket cost is based on where the tickets are located. Based on the number of tickets ordered, a percentage off discount will be applied to the total cost. Finally, if the customer is a preferred customer, they will receive $10 off their order

private void calculateButton_Click(object sender, EventArgs e)
{
    double Box = 75.25;
    double Pavillion = 30.75;
    double Lawn = 21.50;
    double Tickets;
    double discount;
    int Number;

    Number = 0;
    discount = ;

    if (int.TryParse(numberofTicketsTextbox.Text, out Number))
    else MessageBox.Show("Invalid");

    if (boxRadioButton.Checked)
        singleTicketLabel.Text = Box.ToString();

    if (pavilionRadioButton.Checked)
        singleTicketLabel.Text = Pavillion.ToString();

    if (lawnRadioButton.Checked)
        singleTicketLabel.Text = Lawn.ToString();

    switch(discount)
    {
        case_1:

    }
}

I just don't know how to get the Case started to include the discount

Answer 1

Would something like this be useful - adapted straight from the MSDN reference on Switch statements

double discount = 0;
switch (Number)   // <-- AWFUL name for a variable by the way
{
    case 1:       // For one ticket
        discount = 0.9;   // For 10%
        break;
    case 2:       // For two
    case 3:       // or three tickets
        discount = 0.8;   // For 20%
        break;
    default:
        discount = 1;
        break;
}

price -= price_before_discount * discount

Bear in mind as soon as one condition of the switch statement is made then the other options are not assessed and the switch breaks out.

Answer 2

As there is already an answer just another hint:

You can exchange

if (int.TryParse(numberofTicketsTextbox.Text, out Number))
else MessageBox.Show("Invalid");

with

if (!int.TryParse(numberofTicketsTextbox.Text, out Number))
   MessageBox.Show("Invalid");

Notice the difference. In your code you had an empty block after the if statement and just used the else block. By negating with ! you now can use the block of the if statement itself.