由网友(诗酒趁年少)分享简介：下面是我的code public class PItem{public String content;public int count;public int fee;public int amount;public string description;// default valuespublic PItem(S...

下面是我的code

public class PItem
{
    public String content;
    public int count;
    public int fee;
    public int amount;
    public string description;

    // default values
    public PItem(String _content = "", int _count = 0, int _fee = 0, string _description = "", int _amount = 0)
    {
        content = _content;
        count = _count < 0 ? 0 : _count;
        fee = _fee;
        description = _description;
        amount = _amount < 0 ? 0 : _amount;
    }
}

这是里面的一类。当我尝试运行程序给出了这样的错误：

this is inside on a class. when i try to run program gives this error:

默认参数指定不允许

我该如何解决这个问题？

How can i solve this error?

推荐答案

现在的问题是，你不能在C＃版本小于4 可选参数 您在这里可以找到这更多信息。

The problem is that you cannot have optional parameters in C# version less than 4. You can find more information on this here.

您可以解决这个问题是这样的：

You can solve it like this:

public class PItem
{
  public String content;
  public int count;
  public int fee;
  public int amount;
  public String description;
  // default values
  public PItem(): this("", 0, 0, "", 0) {}
  public PItem(String _content): this (_content, 0, 0, "", 0) {}
  public PItem(String _content, int _count): this(_content, _count, 0, "", 0) {}
  public PItem(String _content, int _count, int _fee): this(_content, _count, _fee, "", 0) {}
  public PItem(String _content, int _count, int _fee, string _description): this(_content, _count, _fee, _description, 0) {}
  public PItem(String _content, int _count, int _fee, string _description, int _amount)
  {
      content = _content;
      count = _count < 0 ? 0 : _count;
      fee = _fee;
      description = _description;
      amount = _amount < 0 ? 0 : _amount;
  }
}