ReadCSVfile错误

Question

我有这段代码

    class Player
{
    private string first_name;
    private string middle_name;
    private string last_name;
    private DateTime dob;
    private string nat;
    private char gender;
    public Player(string first_name, string last_name, string middle_name, DateTime dob, string nat, char gender)
    {
        this.first_name = first_name;
        this.last_name = last_name;
        this.middle_name = middle_name;
        this.dob = dob;
        this.nat = nat;
        this.gender = gender;
    }
    public override string ToString()
    {
        return first_name + " " + middle_name + " " + last_name + " " + dob + " " + nat + " " + gender;
    }
    private List<string> content = new List<string>();
    public string FileName { get; set; }
    public string Delimiter { get; set; }
    public ReadCSVFile(string fn, string delim = "|")
    {
        FileName = fn;
        Delimiter = delim;
    }
    public void Load()
    {
        TextFieldParser par = new TextFieldParser(FileName);
        par.TextFieldType = FieldType.Delimited;
        par.SetDelimiters(Delimiter);
        while (!par.EndOfData)
        {
            string[] fields = par.ReadFields();
            foreach (string field in fields)
            {
                Console.WriteLine(field);
            }
        }
        par.Close();
    }
    static void RunReadCSVFile()
    {
        var f = new ReadCSVFile(@"C:\Temp\car1.txt");
        f.Load();
    }

在ToString方法之后我遇到了问题。我尝试创建方法ReadCSVFile时出错。 IDE说“方法必须有一个返回值”。但是，我无法弄明白。

Answer 1

您尝试使用ReadCVSFile，就像它是一个类

var f = new ReadCSVFile(@"C:\Temp\car1.txt");
f.Load();

但没有课程ReadCVSFile。

此行表示您要使用班级

public ReadCVSFile(string filename, string delim = "|") {
}

因为这是构造函数的结构。

但是你没有在任何地方定义课程ReadCVSFile。

我会建议这样的事情

class Player {
    //player properties
    // ...

    public Player(...) { ... }
    public string ToString() { ...}
} //end of class player 


class ReadCVSFile {

    private List<string> content = new List<string>();
    public string FileName { get; set; }
    public string Delimiter { get; set; }
    public ReadCSVFile(string fn, string delim = "|")
    {
        FileName = fn;
        Delimiter = delim;
    }

    public void Load() { ...}

    static void RunReadCSVFile()
    {
        var f = new ReadCSVFile(@"C:\Temp\car1.txt");
        f.Load();
    }
} 

你的代码在这里没有明确播放器类的作用吗？ cvs文件应该包含播放器吗？

Answer 2

方法ReadCSVFile必须关联返回类型，如果方法没有返回任何内容，则将其标记为void。 void指定该方法不返回值。

通过指定访问级别（如public或private），可选修饰符（如abstract或sealed），返回值，方法名称和任何方法参数，在类或结构中声明方法。这些部分一起是该方法的标志。请阅读here了解更多信息。

public void ReadCSVFile(string fn, string delim = "|")
    {
        FileName = fn;
        Delimiter = delim;
    }

Answer 3

    public class Player
    {

    private string first_name;
    private string middle_name;
    private string last_name;
    private DateTime dob;
    private string nat;
    private char gender;

    public Player(string first_name, string last_name, string middle_name, DateTime dob, string nat, char gender)
    {
        this.first_name = first_name;
        this.last_name = last_name;
        this.middle_name = middle_name;
        this.dob = dob;
        this.nat = nat;
        this.gender = gender;
    }

    public override string ToString()
    {
        return first_name + " " + middle_name + " " + last_name + " " + dob + " " + nat + " " + gender;
    }

   private List<string> content = new List<string>();
   public string FileName { get; set; }
   public string Delimiter { get; set; }

   //public static class ReadCSVFile(string fn, string delim = "|")
   //{
   //    FileName = fn;
   //    Delimiter = delim;
   //}

   private void Load()
   {
       TextFieldParser par = new TextFieldParser(FileName);
       par.TextFieldType = FieldType.Delimited;
       par.SetDelimiters(Delimiter);
       while (!par.EndOfData)
       {
           string[] fields = par.ReadFields();
           foreach (string field in fields)
            {
                Console.WriteLine(field);
           }
      }  
      par.Close();
    }

   public void RunReadCSVFile(string fn, string delim = "|")
   {
        //var f = ReadCSVFile(@"C:\Temp\car1.txt");
        //f.Load();
        FileName = fn;
        Delimiter = delim;
        Load();

    }

       static void Main(string[] args)
        {
            Player plr = new Player("First","Last","Middle",DateTime.Now,"nat",'G');
            plr.RunReadCSVFile(@"C:\temp\car1.txt");

        }