显示以前的值答案

【问题标题】：Displaying previous values显示以前的值
【发布时间】：2012-12-04 03:58:46
【问题描述】：

public partial class mainForm : Form
{
    public mainForm()
    {
        InitializeComponent();
    }
    private void btnCalculate_Click(object sender, EventArgs e)
    {
        string customerType = txtCustomerType.Text;
        decimal subtotal = Convert.ToDecimal(txtSubtotal.Text);
        decimal discountPercent = .0m;

        switch (customerType)
        {
            case "R":
                if (subtotal < 100)
                    discountPercent = .0m;
                else if (subtotal >= 100 && subtotal < 250)
                    discountPercent = .1m;
                else if (subtotal >= 250 && subtotal < 500)
                    discountPercent = .25m;
                else if (subtotal >= 500)
                    discountPercent = .30m;
                break;
            case "C":
                discountPercent = .2m;
                break;
            case "T":
                if (subtotal < 500)
                    discountPercent = .4m;
                else if (subtotal >= 500)
                    discountPercent = .5m;
                break;
            default:
                discountPercent = .1m;
                break;
        }

            decimal discountAmount = subtotal * discountPercent;
            decimal invoiceTotal = subtotal - discountAmount;

            txtDiscountPercent.Text = discountPercent.ToString("p1");
            txtDiscountAmount.Text = discountAmount.ToString("c");
            txtTotal.Text = invoiceTotal.ToString("c");

            txtCustomerType.Focus();            
        }


    private void btnExit_Click(object sender, EventArgs e)
    {

        int i = 0;
        string summaryString = txtTotal.Text;
        for (i = 0; i < 5; i++)
            summaryString += Environment.NewLine;

        MessageBox.Show(summaryString, "Order Totals");

        this.Close();
    }
}

一旦用户点击计算按钮，它就会计算发票总额。我需要做的就是存储前 5 个总值，并让它们在新行上一个接一个地显示在消息框中。一旦用户单击退出按钮，该消息框就会显示出来。

【问题讨论】：

您应该将此标记为家庭作业，并告诉我们具体给您带来的问题。我们不是一个“复制粘贴让这项工作”的社区。span>
@SimonWhitehead 作业标签已被弃用。

标签： c# arrays loops

【解决方案1】：

这样的事情可能会为您指明正确的方向：

public partial class mainForm : Form
{
    public mainForm()
    {
        InitializeComponent();
    }

    private List<string> _totals = new List<string>();

    private void btnCalculate_Click(object sender, EventArgs e)
    {
            string customerType = txtCustomerType.Text;
            decimal subtotal = Convert.ToDecimal(txtSubtotal.Text);
            decimal discountPercent = .0m;

            switch (customerType)
            {
                case "R":
                    if (subtotal < 100)
                        discountPercent = .0m;
                    else if (subtotal >= 100 && subtotal < 250)
                        discountPercent = .1m;
                    else if (subtotal >= 250 && subtotal < 500)
                        discountPercent = .25m;
                    else if (subtotal >= 500)
                        discountPercent = .30m;
                    break;
                case "C":
                    discountPercent = .2m;
                    break;
                case "T":
                    if (subtotal < 500)
                        discountPercent = .4m;
                    else if (subtotal >= 500)
                        discountPercent = .5m;
                    break;
                default:
                    discountPercent = .1m;
                    break;
            }

            decimal discountAmount = subtotal * discountPercent;
            decimal invoiceTotal = subtotal - discountAmount;

            txtDiscountPercent.Text = discountPercent.ToString("p1");
            txtDiscountAmount.Text = discountAmount.ToString("c");
            txtTotal.Text = invoiceTotal.ToString("c");
            _totals.Add(txtTotal.Text);

            txtCustomerType.Focus();
        }


        private void btnExit_Click(object sender, EventArgs e)
        {
            MessageBox.Show(string.Join(Environment.NewLine, _totals.ToArray()), "Order Totals");
            this.Close();
        }

}

【讨论】：

【解决方案2】：

试试这个。这只会为您提供最后五个总数：

public partial class mainForm : Form
{
public mainForm()
{
    InitializeComponent();
}

private List<string> allTotals = new List<string>();

private void btnCalculate_Click(object sender, EventArgs e)
{
        string customerType = txtCustomerType.Text;
        decimal subtotal = Convert.ToDecimal(txtSubtotal.Text);
        decimal discountPercent = .0m;

        switch (customerType)
        {
            case "R":
                if (subtotal < 100)
                    discountPercent = .0m;
                else if (subtotal >= 100 && subtotal < 250)
                    discountPercent = .1m;
                else if (subtotal >= 250 && subtotal < 500)
                    discountPercent = .25m;
                else if (subtotal >= 500)
                    discountPercent = .30m;
                break;
            case "C":
                discountPercent = .2m;
                break;
            case "T":
                if (subtotal < 500)
                    discountPercent = .4m;
                else if (subtotal >= 500)
                    discountPercent = .5m;
                break;
            default:
                discountPercent = .1m;
                break;
        }

        decimal discountAmount = subtotal * discountPercent;
        decimal invoiceTotal = subtotal - discountAmount;

        txtDiscountPercent.Text = discountPercent.ToString("p1");
        txtDiscountAmount.Text = discountAmount.ToString("c");
        txtTotal.Text = invoiceTotal.ToString("c");
        allTotals.Add(txtTotal.Text);

    if (allTotals.Count > 5) allTotals.RemoveAt(0);

        txtCustomerType.Focus();
    }


    private void btnExit_Click(object sender, EventArgs e)
    {
        MessageBox.Show(string.Join(Environment.NewLine, allTotals.ToArray()), "Order Totals");
        this.Close();
    }

}

【讨论】：