C#:从基类静态方法确定派生对象类型

尝试使用泛型:

public static BaseClass Create() where T : BaseClass, new()
{
    T newVar = new T();
    // Do something with newVar
    return T;
}

样品用途:

DerivedClass d = BaseClass.Create();

摘要

有两个主要选择.更好更新的是使用泛型,另一种是使用反射.我提供这两个以防你需要开发一个在.NET 2.0之前工作的解决方案.

泛型

abstract class BaseClass
{
  public static BaseClass Create() where T : BaseClass, new()
  {
    return new T();
  }
}

用法如下:

DerivedClass derivedInstance = BaseClass.Create();

反射

abstract class BaseClass
{
  public static BaseClass Create(Type derivedType)
  {
    // Cast will throw at runtime if the created class
    // doesn't derive from BaseClass.
    return (BaseClass)Activator.CreateInstance(derivedType);
  }
}

使用的位置(为了便于阅读,分为两行):

DerivedClass derivedClass
    = (DerivedClass)BaseClass.Create(typeof(DerivedClass));