Question

    private void btnCalculate_Click(object sender, RoutedEventArgs e)
    {
        double pay;
        pay = 0.00;

        double add;
        add = 0.00;


        int age;
        age = int.Parse(txtAge.Text);

        string month;
        month = txtMonth.Text;


           if (age >= 18 && age <= 55)
           {
               pay = 350;
           }

           else if (age <= 18)
           {
               pay = 150;                   //if-else-if statements depending on age
           }

           else if (age > 55)
           {
               pay = 35;
           }

        switch (month)
        {
            case "January":
            case "january":
            case "July":
            case "july":          //switch statement, how much you pay depending on month
                add = 100;
                break;


            case "February":
            case "february":
            case "August":
            case "august":
                add = 120;
                break;

            case "March":
            case "march":
            case "September":
            case "september":
                add = 140;
                break;

            case "April":
            case "april":
            case "October":
            case "october":
                add = 160;
                break;

            case "May":
            case "may":
            case "November":
            case "november":
                add = 180;
                break;

            case "June":
            case "june":
            case "December":
            case "december":
                add = 120;
                break;
        }

           lblTotal.Content = (pay + add) * 1.13; //calculation that prints to the label

    }

因此，当我运行代码时，它只在标签中输出0 如果我将计算放在底部（见此处），它会说一些关于标签无法访问的内容。任何帮助都会很棒。代码已经解决

Answer 1

您可以直接分配变量。声明和指配不一定是不同的声明。
18有两个不同的检查：if中的＆gt; = 18，而第一个if中的＆lt; = 18。不是代码错误，而是语义错误。
最终分配在交换机块内部且无法访问。把它放在开关外面。

看起来您正在使用WPF？如果是这样，您应该查看MVVM模式以及数据绑定。在WPF中学习并不容易但非常重要。但是，在大多数情况下，它将不再需要查询和编写元素的属性 - 因为它将由运行时处理。

还要考虑在本月使用ComboBox。更容易验证数据。

Answer 2

根据建议，您的标签分配在switch声明中，导致它不会执行，除非月份是6月或12月。

无论如何，我建议你简化。

试试这个：

private void btnCalculate_Click(object sender, RoutedEventArgs e)
{
    int age = int.Parse(txtAge.Text);
    double pay = age <= 18 ? 150.0 : (age > 55 ? 35.0 : 350.0);

    int index = (DateTime.Parse("1 " + txtMonth.Text).Month - 1) % 6;
    double[] choices = new [] { 100.0, 120.0, 140.0, 160.0, 180.0, 120.0 };
    double add = choices[index];

    lblTotal.Content = (pay + add) * 1.13;
}

Answer 3

标签分配在switch语句中。您还可以对代码进行许多其他改进。

对于初学者，您还可以加入变量的赋值和声明，并在switch中使用.ToLower（）来节省额外的情况：

    private void btnCalculate_Click(object sender, RoutedEventArgs e)
    {
        var pay = 0.00;
        var add = 0.00;
        var age = int.Parse(txtAge.Text);
        var month = txtMonth.Text;

        if (age >= 18 && age <= 55)
        {
            pay = 350;
        }
        else if (age <= 18)
        {
            pay = 150;
        }
        else if (age > 55)
        {
            pay = 35;
        }

        switch (month.ToLower())
        {
            case "january":
            case "july":
                add = 100;
                break;

            case "february":
            case "august":
            case "june":
            case "december":
                add = 120;
                break;

            case "march":
            case "september":
                add = 140;
                break;

            case "april":
            case "october":
                add = 160;
                break;

            case "may":
            case "november":
                add = 180;
                break;
        }

        lblTotal.Text = Convert.ToString((pay + add) * 1.13); //calculation that prints to the label
    }

为什么我对此代码的计算不起作用？

3 个答案: