我有抽象基类,包含一些字段和一些作用于这些字段的方法.例如：
public abstract class A
{
protected double _field;
public double SquaredField { get { return _field * _field; } }
... some other abstract methods
}
我想强制A的所有孩子在他们的构造函数中初始化_field
public class B : A
{
public B(double field)
{
_field = Math.Sqrt(field);
}
... some other method implementations
}
实现这一目标的正确模式是什么？
– 编辑
我最终做的是：
public abstract class A
{
protected readonly double _field;
public A(double field)
{
_field = field;
}
public double SquaredField { get { return _field * _field; } }
... some other abstract methods
}
public class B : A
{
public B(double field) : base(field)
{
}
public static B CreateNew(double val)
{
return new B(Math.Sqrt(field));
}
... some other method implementations
}
解决方法
根本不要将字段公开给派生类.相反,创建一个受保护的抽象属性：
public abstract class A
{
protected double Field { get; }
public double SquaredField { get { return Field * Field; } }
}
或者,如果字段对于特定实例应始终保持不变,请将其作为构造函数参数并将其保持为私有：
public abstract class A
{
private readonly double _field;
public double SquaredField { get { return _field * _field; } }
protected A(double field)
{
_field = field;
}
}
