Question

这就是我所拥有的，我需要让控制台不要在主程序上返回额外的逗号，所以我可能需要重写字符串e。月份，描述等应该仍然有逗号，但如果没有“注释”之类的东西，那些额外的逗号就会消失。

    public override string ToString()
    {
        string e = description + ", " + month + day + year + ", " + amount.ToString("C") + ", ";
            e = e + paymentMethod + ", " +  trip + ", " + note;

        return e;

    }

Answer 1

您可以尝试这样的方法来过滤掉空元素：

public override string ToString()
{
    string[] elements = new string[] { description, 
                String.Concat(month, day, year),
                amount.ToString("C"), paymentMethod, trip, note };

    return String.Join(", ", elements.Where(s => !String.IsNullOrWhiteSpace(s)));
}

更冗长的选项，但也更少混淆和C＃2兼容：

private static void AddIfNotNull(List<string> elements, string value)
{
    if (!String.IsNullOrEmpty(value))
        elements.Add(value);
}

public override string ToString()
{
    List<string> elements = new List<string>();
    AddIfNotNull(elements, description);
    elements.Add(String.Concat(month, day, year));
    elements.Add(amount.ToString("C"));
    AddIfNotNull(elements, paymentMethod);
    AddIfNotNull(elements, trip);
    AddIfNotNull(elements, note);
    return String.Join(", ", elements.ToArray());
}

Answer 2

您可以像这样重写ToString，这是您想要的吗？

public override string ToString()
{
    string e = description + " " + month + day + year + " " + 
        amount.ToString("C") + " ";
    e = e + paymentMethod + " " +  trip + " " + note;

    return e;
}

从C＃构造函数中删除额外的逗号

2 个答案: