我可以重写 c # 中的属性吗? 怎么做？

我有一个基础类:

abstract class Base
{
public int x
{
get { throw new NotImplementedException(); }
}
}

还有下面这个后代:

class Derived : Base
{
public int x
{
get { //Actual Implementaion }
}
}

当我编译的时候，我得到一个警告，说派生类的 x定义将隐藏 Base 的版本。是否可以在类似 c # 的方法中重写属性？

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小开
最佳答案

You need to use virtual keyword

abstract class Base
{
// use virtual keyword
public virtual int x
{
get { throw new NotImplementedException(); }
}
}

or define an abstract property:

abstract class Base
{
// use abstract keyword
public abstract int x { get; }
}

and use override keyword when in the child:

abstract class Derived : Base
{
// use override keyword
public override int x { get { ... } }
}

If you're NOT going to override, you can use new keyword on the method to hide the parent's definition.

abstract class Derived : Base
{
// use new keyword
public new int x { get { ... } }
}
小开

Make the base property abstract and override or use the new keyword in the derived class.

abstract class Base
{
public abstract int x { get; }
}


class Derived : Base
{
public override int x
{
get { //Actual Implementaion }
}
}

Or

abstract class Base
{
public int x { get; }
}


class Derived : Base
{
public new int x
{
get { //Actual Implementaion }
}
}
小开

Change property signature as shown below:

Base class

public virtual int x
{ get { /* throw here*/ } }

Derived class

public override int x
{ get { /*overriden logic*/ } }

If you do not need any implementation in Base class just use abstract property.

Base:

public abstract int x { get; }

Derived:

public override int x { ... }

I would suggest you using abstract property rather than trhowing NotImplemented exception in getter, abstact modifier will force all derived classes to implement this property so you'll end up with compile-time safe solution.

小开 
abstract class Base
{


public virtual int x
{
get { throw new NotImplementedException(); }
}
}

or 

abstract class Base
{
// use abstract keyword
public abstract int x
{
get;
}
}

In both case you have to write in the derived class

public override int x
{
get { your code here... }
}

difference between the two is that with abstract you force the derived class to implement something, and with virtaul you can provide a default behavior that the deriver can use as is, or change.

小开 
abstract class Base
{
// use abstract keyword
public virtual int x
{
get { throw new NotImplementedException(); }
}
}

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