相关疑难解决方法(0)

我有这两个分别被称为的类:Malicious和MaliciousSmall:

恶意代码:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DataModel.MaliciousCode
{
    public class Malicious : MaliciousSmall
    {
    }
}

恶意代码小:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Diagnostics;
using System.Data;
namespace DataModel.MaliciousCode
{
    public class MaliciousSmall
    {
        public int Id { get; set; }
        public int MaliciousCodeAlertId { get; set; }
        public string SourceId { get; set; }
        public int MalCodeID { get; set; }
        ...................................................... …

在我的方法中,我有这个查询:

var query =
    _db.STEWARDSHIP
        .OrderBy(r => r.SITE.SITE_NAME)
        .Where(r => SiteId == null || r.SITE_ID == iSiteId)
        .Where(r => SiteTypeId == null || r.SITE.SITE_TYPE_VAL.SITE_TYPE_ID == iSiteTypeId)
        .Where(r => EcoregionId == null || r.SITE.ECOREGION_VAL.ECOREGION_ID == iEcoregionId)
        .Where(r => ConservationAreaId == null || r.SITE.CONSERVATION_AREA_VAL.CONSERVATION_AREA_ID == iConservationAreaId)
        .Where(r => VisitTypeId == null || r.VISIT_TYPE_VAL.VISIT_TYPE_ID == iVisitTypeId)
        .Where(r => Staff == null || r.STAFF.Contains(sStaff))
        .Where(r => Comment == null || r.VISIT_COMMENTS.Contains(sComment))
        .Select(r => new SiteVisitDetails
        {
            Id = r.STEWARDSHIP_ID,
            Name = r.SITE.SITE_NAME,
            VisitType = …

首先,这不是一个重复的问题.

我知道以下事实:

• 在继承期间,构造函数的执行顺序将与它们的派生顺序相同,并且析构函数的执行顺序将与它们的派生顺序相反.
• 此外,我们可以base在构造函数定义中使用关键字显式调用基类构造函数.

我的问题是:对于我的下面的代码

class ClassA
{
    public ClassA(int a)
    {
        Console.WriteLine("Parameterized Constructor of ClassA");
    }
}
class ClassB : ClassA
{
    public ClassB(int a)
    {
        Console.WriteLine("Parameterized Constructor of ClassB");
    }
}
class ClassC : ClassB
{
    public ClassC(int a)
    {
        Console.WriteLine("Parameterized Constructor of ClassC");
    }
}

class Program
{
    static void Main(string[] args)
    {
        ClassC classc = new ClassC(1);
        Console.ReadLine();
    }
}

我得到了complie时间错误:

'ClassA' does not contain a constructor that takes 0 arguments
'ClassB' does …

我有一个基类:

public class Base {
  public string Foo { get; set; }
  public float Bar { get; set; }
  public float Foobar { get; set; }

  public Base (string foo, float bar, float foobar) {
      Foo = foo;
      Bar = bar;
      Foobar = foobar;
  }
}

当我尝试添加扩展此类的类时,我收到错误:

public class Derived : Base {
    public Base derived = new Derived ("Foo", 0f, 0f);
}

收到的错误说明如下: Base does not contain a constructor that takes 0 arguments

我在Derived类的第1行得到了这个错误.任何修复/原因导致这种情况发生？

我很困惑为什么这不会运行.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication3
{
    class Buyer : User
    {
        public void AuctionWon()
        {
        }
    }
}

我得到"不包含带0参数的构造函数".我事前已经寻求帮助,但没有结果有帮助.

这是用户类

public class User
{

    private int accountNo;
    private int password;

    public User(int accountNo, int password)
    {
        this.accountNo = accountNo;
        this.password = password;

    }

    public bool Validatepassword(int userpassword)
    {
        if (password == userpassword)
        {
            return true;
        }
        else
        {
            return false;
        }
    }

    public int GetAccountNo()
    {
        return accountNo;
    }
}