不包含带有3个参数的构造函数

Question

please bear with me as I'm just learning C#. Just messing around with C# I decided to come up with an inventory system to test out but I have one problem in my script:

using System;
using System.Collections.Generic;


public class Item
{
    public String name;
    public int pesos;

    public int getPesos()
    {
        return pesos;
    }
    public String getName()
    {
        return name;
    }
}
public class statuseffect
{
    statuseffect(string Effect,int Amount,int Duration)
    {
        string effect = Effect;
        int amount = Amount;
        int duration = Duration;
    }
}
public class Potion : Item 
{
    public int hpeffect;
    public int mpeffect;
    List<statuseffect> effects = new List<statuseffect>();


    public Potion(int hp,int mp)
    {
        hpeffect = hp;
        mpeffect = mp;
    }
    public void addEffect(statuseffect eff)
    {
        effects.Add(eff);
    }
}
class game
{
public static void Main()
    {   
        Potion healthPotion = new Potion(200,50);
        healthPotion.pesos = 23;
        Console.WriteLine(healthPotion.hpeffect);
        statuseffect slow = new statuseffect("slow",10,30);
    }
}

in the last line the compiler tells me that statuseffect does not contain a constructor that takes 3 arguments. From what I can tell, it does contain 3 arguments. Is there something I am missing here?

as a side note. if you guys have any comments or suggestions for my script, that would be helpful as well.

Answer 1

Your constructor is private and therefore "invisible" to code outside the class itself. Try adding the keyword internal before the constructor. Or, if it needs to be visible from other projects as well, add public instead.

Another issue: In your class statuseffect , you declare three local variable inside your constructor. Those variable's only scope is the constructor. You must move their declarations out of the constructor (then they become instance fields of the class). The constructor can still assign to them.

Answer 2

您的构造函数需要标记为public 。

Answer 3

As c# is specifically an Objectt oriented language so every thing you declare in a class without an access specifier it is regarded as private by the compiler. So declare your constructor public , that will solve the case

public statuseffect(string Effect,int Amount,int Duration)
    {
        string effect = Effect;
        int amount = Amount;
        int duration = Duration;
    }

Answer 4

Make your constructor public. When you dont specify any access-specifier by default it becomes private, means it can only be used inside your class. Making it public makes it accessible from outside.

public class statuseffect
{
  public statuseffect(string Effect,int Amount,int Duration)
  {
    string effect = Effect;
    int amount = Amount;
    int duration = Duration;
  }
}

Moreover do something with those variables, they are of no use.

Answer 5

public static void Populare_Books()
{
    Books[] bks = { new Books(1, "Shogun", "James Clavell"), new Books(2, "Pe aripile vantului", "Margaret Mitchell"), new Books(3, "MANDRIE SI PREJUDECATA", "Jane Austen"), new Books(4, "ANNA KARENINA", " Lev Tolstoi"), new Books(5, "Notre-Dame de Paris", "Victor Hugo"), new Books(6, "Marile speranțe", "Charles Dickens"), new Books(7, "Ion", "Liviu Rebreanu"), new Books(8, "Cărțile junglei", "Rudyard Kipling")};
    MySqlConnection con = new MySqlConnection("DataSource=localhost; UserID=root;database=" + nume);
    con.Open();
    MySqlCommand cmd = con.CreateCommand();
    cmd.CommandText = "INSERT INTO Books (BookID, Title, ISBN, Number, NumberLeft) VALUES (@BookID, (@Title, (@ISBN, (@Number, (@NumberLeft)";
    MySqlTransaction tra = con.BeginTransaction();
    try
    {
        cmd.Transaction = tra;
        foreach (Books bo in bks)
        {
            cmd.Parameters.AddWithValue("@BookID", bo.BookID);
            cmd.Parameters.AddWithValue("@Title", bo.Title);
            cmd.Parameters.AddWithValue("@ISBN", bo.ISBN);
            cmd.Parameters.AddWithValue("@Number", bo.Number);
            cmd.Parameters.AddWithValue("@NumberLeft", bo.NumberLeft);
            cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
        }
        tra.Commit();
        Console.WriteLine("Tabelul Books a fost umplut");
        con.Close();
    }
    catch (Exception ex)
    {
        tra.Rollback();
        Console.WriteLine(ex.Message);
    }
}