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[英]Unable to explicitly cast a child class to another child class inside explicit implementation of interface in generic parent base class
[英]Calling base implementation of an accessor inside base class, getting child implementation
我试图在我们的代码库中设置一系列对象,以便能够使用 HTML 提供格式良好的字符串表示。 但是,当我尝试检索子类的通知文本时,当它获取父访问器时,它会检索子类的NotificationFormat
实现,而不是基类NotificationFormat
。
尝试通过使用this
来澄清没有区别,Resharper 建议删除多余的限定符。 如果我改为将子类更改为在我尝试保留的方法上使用new
,那么当我访问被视为基类的子类上的NotificationText
时,我只会得到基类NotificationText
。 我曾认为没有办法从父级访问任何子级实现。
我的目标是能够在可能是基类或子类的对象上调用NotificationText
。 如果我在一个实际上是子类的对象上调用它,我想使用子实现并让它回调到基类格式信息的基实现。
using System;
using System.Linq;
using System.Collections.Generic;
using System.IO;
public class Program
{
public static void Main()
{
var TestB = new B();
TestB.Details = "Some Details";
TestB.Name = "A Name";
TestB.ID = 1;
Console.WriteLine(TestB.NotificationText); // works
var TestA = (A)TestB;
Console.WriteLine(TestA.NotificationText); // only returns A notification Text
}
}
public class A
{
public long? ID {get;set;}
public virtual string NotificationFormat
{
get
{
return "<h3>General Details</h3>" +
"<table> " +
"<tr>" +
"<td>Id:</td>" +
"<td>{0}</td>" +
"</tr>" +
"</table>";
}
}
public virtual string NotificationText
{
get
{
return string.Format(NotificationFormat, ID);
}
}
}
public class B : A
{
public string Name {get;set;}
public string Details {get;set;}
// chnage override to new to get it to compile
public override string NotificationFormat
{
get
{
return "<h3>Specific Details</h3>" +
"<table> " +
"<tr>" +
"<td>Name:</td>" +
"<td>{0}</td>" +
"</tr>" +
"<tr>" +
"<td>Details:</td>" +
"<td>{1}</td>" +
"</tr>" +
"</table>";
}
}
// chnage override to new to get it to compile
public override string NotificationText
{
get
{
var baseNotification = base.NotificationText;
return baseNotification + string.Format(NotificationFormat, Name, Details);
}
}
}
由于NotficationFormat
是virtual
对Notification
任何调用都将调用最派生的实现。 当你调用base.NotificationText
类B
,在代码A.NotificationText
使得一个虚拟呼叫NotificaitonFormat
所以它会调用B.NotificationFormat
。 听起来您不希望NotificationFormat
是虚拟的:
public class A
{
public long? ID {get;set;}
private string NotificationFormat
{
get
{
return "<h3>General Details</h3>" +
"<table> " +
"<tr>" +
"<td>Id:</td>" +
"<td>{0}</td>" +
"</tr>" +
"</table>";
}
}
public virtual string NotificationText
{
get
{
return string.Format(NotificationFormat, ID);
}
}
}
public class B : A
{
public string Name {get;set;}
public string Details {get;set;}
private string NotificationFormat
{
get
{
return "<h3>Specific Details</h3>" +
"<table> " +
"<tr>" +
"<td>Name:</td>" +
"<td>{0}</td>" +
"</tr>" +
"<tr>" +
"<td>Details:</td>" +
"<td>{1}</td>" +
"</tr>" +
"</table>";
}
}
// change override to new to get it to compile
public override string NotificationText
{
get
{
var baseNotification = base.NotificationText;
return baseNotification + string.Format(NotificationFormat, Name, Details);
}
}
}
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