派生类的C＃强制转换

Question

一个菜鸟问题...

我有两节课，一个普通的（父母）课和一个专门的（孩子）课：

public abstract class BaseTest
{
   public BaseTestSettings Settings{get;set;}
   public abstract void Run();
}

public class BaseTestSettings
{
   public double SettingsProp1{get;set;}
   public double SettingsProp1{get;set;}
}

public class SpecializaedTestSettings : BaseTestSettings
{
   public double SpecializaedTestSettingsPropA{get;set;}
   public double SpecializaedTestSettingsPropB{get;set;}
}

public class SpecializaedTest : BaseTest
{
   public SpecializaedTest()
   {
      this.Settings = new SpecializaedTestSettings();
   }

   public override void Run()
   {
      SpecializaedTestSettings settings = (SpecializaedTestSettings)this.Settings;
   }
}

有没有一种方法可以避免在专用测试中使用覆盖的Run方法进行转换？ 我猜一个解决方案是在SpecializedTest类中定义SpecializedTestSettings类型的Settings属性，但是我的目标是避免这种情况，只声明一次这些属性。 我想我不能吗？

Answer 1

使用泛型 ：

public abstract class BaseTest<TSettings> where TSettings : BaseTestSettings
{
   public TSettings Settings{get;set;}
   public abstract void Run();
}

public class BaseTestSettings
{
   public double SettingsProp1{get;set;}
   public double SettingsProp1{get;set;}
}

public class SpecializaedTestSettings : BaseTestSettings
{
   public double SpecializaedTestSettingsPropA{get;set;}
   public double SpecializaedTestSettingsPropB{get;set;}
}

public class SpecializaedTest : BaseTest<SpecializaedTestSettings>
{
   public SpecializaedTest()
   {
      this.Settings = new SpecializaedTestSettings();
   }

   public override void Run()
   {
      SpecializaedTestSettings settings = this.Settings;
   }
}

如果您需要非通用/协变版本，则可以编写协变接口或非通用基本类型。