这是丹尼尔发布答案时我正在处理的示例代码。看起来它正在按照他的建议做:
public static class BaseFactory
{
public static Base Create(bool condition)
{
if (condition)
{
return Derived1.Create(1, "TEST");
}
else
{
return Derived2.Create(1, DateTime.Now);
}
}
}
public class Base
{
protected Base(int value)
{
}
protected static Base Create(int value)
{
return new Base(value);
}
}
public sealed class Derived1: Base
{
private Derived1(int value, string text): base(value)
{
}
internal static Derived1 Create(int value, string text)
{
return new Derived1(value, text);
}
}
public sealed class Derived2: Base
{
private Derived2(int value, DateTime time): base(value)
{
}
internal static Derived2 Create(int value, DateTime time)
{
return new Derived2(value, time);
}
}
[编辑] 对于丹尼尔的第二个建议:
public static class BaseFactory
{
public static Base Create(bool condition)
{
if (condition)
{
return new Derived1Creator(1, "TEST");
}
else
{
return new Derived2Creator(1, DateTime.Now);
}
}
private sealed class Derived1Creator: Derived1
{
public Derived1Creator(int value, string text): base(value, text)
{
}
}
private sealed class Derived2Creator: Derived2
{
public Derived2Creator(int value, DateTime time): base(value, time)
{
}
}
}
public class Base
{
protected Base(int value)
{
}
protected static Base Create(int value)
{
return new Base(value);
}
}
public class Derived1: Base
{
protected Derived1(int value, string text): base(value)
{
}
protected static Derived1 Create(int value, string text)
{
return new Derived1(value, text);
}
}
public class Derived2: Base
{
protected Derived2(int value, DateTime time): base(value)
{
}
protected static Derived2 Create(int value, DateTime time)
{
return new Derived2(value, time);
}
}
请注意,不幸的是,第二种方法意味着无法密封类。