Question

我输入了这个代码作为家庭作业，它的工作原理。但是，方法部分不正确。该方法应从表单中获取2个值（批发价格和标记百分比）作为参数并返回零售价格。这是我到目前为止所做的，我只是想知道我需要移动到哪里才能使方法正确。

    {
        InitializeComponent();
    }
    private void CalculateRetail()//method header
     {//method body
        decimal Cost, //variables
                Percent,
                Perc,
                PercAmt,
                FinCost;

        Cost = Convert.ToDecimal(txtCost.Text);
        Percent = Convert.ToDecimal(txtPercent.Text);

        Perc = (Percent / 100);
        PercAmt = Cost * Perc;
        FinCost = Cost + PercAmt;

        lblFinCost.Text = "The Retail Price with markup is " + FinCost.ToString("C2"); //output to label
    }//end method body
    private void btnCalc_Click(object sender, EventArgs e)
    {
        decimal Cost;
        decimal Percent;

        lblFinCost.Text = "";

        if (string.IsNullOrEmpty(txtCost.Text)) // input validation check to make sure not blank
        {
            MessageBox.Show("Please enter a number for the cost", "Error");
            return;
        } //end if

        if (!decimal.TryParse(txtCost.Text, out Cost)) // input validation check to make sure is whole number
        {
            MessageBox.Show("Please enter a number for the cost", "Error");
            return;
        }
        if (string.IsNullOrEmpty(txtPercent.Text)) // input validation check to make sure not blank
        {
            MessageBox.Show("Please enter a number for the cost", "Error");
            return;
        } //end if

        if (!decimal.TryParse(txtPercent.Text, out Percent)) // input validation check to make sure is whole number
        {
            MessageBox.Show("Please enter a number for the cost", "Error");
            return;
        }
        CalculateRetail(); //call method once error check passes
    }

    private void btnClear_Click(object sender, EventArgs e)
    {
        txtCost.Text = "";//clear form
        txtPercent.Text = "";
        lblFinCost.Text = "";

    }

    private void btnExit_Click(object sender, EventArgs e)
    {
        this.Close(); //close form
    }

Answer 1

考虑到在检查字段是否为空或无法转换为小数时显示相同的错误，请将两者合并：

if (string.IsNullOrEmpty(txtCost.Text) || !decimal.TryParse(txtCost.Text, out cost))
{
    MessageBox.Show("Please enter a number for the cost", "Error");
    return;
}

（与txtPercent相同。）

您的主要问题是您不使用参数。您的方法可以像这样重写：

private void CalculateRetail(decimal cost, decimal percent)
{
    var percAmt = Cost * (percent / 100);
    var finCost = cost + percAmt;

    lblFinCost.Text = "The Retail Price with markup is " + finCost.ToString("C2");
}

然后这样叫：

CalculateRetail(cost, percent);

请注意，局部变量应该是CamelCase，而不是PascalCase，即它们不应该以大写字母开头。

同时避免仅描述我们已经看到的内容的评论;这些只会弄乱你的代码：

//end method body
//output to label
//variables

顺便说一句，finCost和percAmt等变量名称很糟糕。使用正确的描述性名称不会受到惩罚;如果他或她不必首先弄清楚变量包含什么，下一个出现的人将更容易维护你的代码。

接收批发成本和标记％作为参数并返回零售价格的方法c＃

1 个答案: