Question

我有以下类，当我在BaseScriptConfigurationList上调用CreateQuerySettings时，它会从QuerySettings返回新的ConfigurationList，而不是HierarchicalQuerySettings中的BaseScriptConfigurationList值1}}：

public abstract class ConfigurationList<TConfigurationObject, TPropertyEnum>
{
  public QuerySettings<TConfigurationObject, TPropertyEnum> CreateQuerySettings()
  {
    return new QuerySettings<TConfigurationObject, TPropertyEnum>();
  }
}

public class BaseScriptConfigurationList : EditableConfigurationList<BaseScriptConfiguration, BaseScriptConfiguration.Property>
{
  public BaseScriptConfigurationList(ConfigurationManager configurationManager)
    : base(configurationManager, InternalAdminObjectType.BaseScript)
  {
     _BaseScriptPageListWatcher = new ConfigurationList<BaseScriptPageConfiguration, BaseScriptPageConfiguration.Property>.
     ConfigurationWatcher(null);

      _ConfigurationWatcher.ChildWatchers.Add(_BaseScriptPageListWatcher);

  }

  public new QuerySettings<BaseScriptConfiguration, BaseScriptConfiguration.Property> CreateQuerySettings()
  {
    return new HierarchicalQuerySettings<BaseScriptConfiguration, BaseScriptConfiguration.Property, BaseScriptQueryChildrenSettings>();
  }
}

编辑：我从TConfigurationObjectList为BaseScriptConfigurationList的其他班级拨打电话。我已将构造函数添加到上面的代码中，以便您可以看到它正在做什么。请注意，EditableConfigurationList继承自ConfigurationList。

TConfigurationObjectList cl = (TConfigurationObjectList)typeof(TConfigurationObjectList).GetConstructor(new Type[] { typeof(ConfigurationManager) }).Invoke(new object[] { Manager.ConfigurationManager });
var querySettings = cl.CreateQuerySettings();

当我进行此调用时，它将进入ConfigurationList.CreateQuerySettings方法。

如何隐藏CreateQuerySettings方法，以便当我从BaseScriptConfigurationList类调用它时，我会得到一个HierarchicalQuerySettings对象？

Answer 1

new修饰符可能是令人讨厌的。请注意，您在示例中隐藏而非覆盖。您没有显示该部分代码，但我认为您遇到了这种情况：

class Base
{
   public static void BaseMethod() { Console.WriteLine("BASE!"); }
}

class Derived : Base
{
   // Hides Base.BaseMethod()
   new public static void BaseMethod() { Console.WriteLine("DERIVED!"); }   
}

Base a = new Base();
a.BaseMethod(); // -> "BASE!"

Base b = new Derived();
b.BaseMethod(); // -> "BASE!"

Derived b = new Derived();
b.BaseMethod(); // -> "DERIVED!"

Answer 2

BaseScriptConfigurationList.CreateQuerySettings() 您的返回类型为QuerySettings<T,T>，因此您始终会将该类型作为返回值，但您将返回HierarchicalQuerySettings。您可以将CreateQuerySettings()的返回类型更改为HierarchicalQuerySettings或两个，将对象转换为其子类型＆＃34; HierarchicalQuerySettings＆＃34;。如果你真的想要隐藏它，你可以这样做：

public class newclass : BaseScriptConfigurationList
{
    public new HierarchicalQuerySettings<BaseScriptConfiguration, BaseScriptConfiguration.Property> CreateQuerySettings()
    {
        return (HierarchicalQuerySettings<BaseScriptConfiguration, BaseScriptConfiguration.Property>)base.CreateQuerySettings();
    }
}

但这并不是很有效，我建议不要这样做。就像我说的，我可能会错过其他一些要求，但是基于你给出的信息......

基本上，我TConfigurationObjectList来自ConfigurationList的{{1}} Inhertis沿着某个地方，依此类推，直到EditableConfigurationList }。由于您正在动态创建类TConfigurationObjectList的实例，并从该点调用该方法，因此您将调用基类ConfigurationList成员CreateQuerySettings。您无权访问新的CreateQuerySettings。如果此时正在创建类BaseScriptConfigurationList实例，请转换对象((BaseScriptConfigurationList)cl).CreateQuerySettings()。话虽如此。如果你不知道你在运行时有什么：

var obj = typeof(TConfigurationObjectList).GetConstructor(new Type[] { typeof(ConfigurationManager) }).Invoke(new object[] { Manager.ConfigurationManager });
var cl = (obj  as BaseScriptConfigurationList) ?? (TConfigurationObjectList)obj;
// or do something else
var querySettings = cl.CreateQuerySettings();

注意我假设您的架构大致设置如下：

public abstract class ConfigurationList<TConfigurationObject, TPropertyEnum>
{
    public QuerySettings<TConfigurationObject, TPropertyEnum> CreateQuerySettings()
    {
        return new QuerySettings<TConfigurationObject, TPropertyEnum>();
    }
}

public class TConfigurationObjectList : ConfigurationList<BaseScriptConfiguration, BaseScriptConfiguration.Property>
{

}

public class EditableConfigurationList<T, T1> : TConfigurationObjectList
{
    protected EditableConfigurationList(ConfigurationManager configurationManager, object baseScript)
    {
        throw new NotImplementedException();
    }
}

public class BaseScriptConfigurationList : EditableConfigurationList<BaseScriptConfiguration, BaseScriptConfiguration.Property>
{
    public BaseScriptConfigurationList(ConfigurationManager configurationManager)
        : base(configurationManager, InternalAdminObjectType.BaseScript)
    {

    }

    public new QuerySettings<BaseScriptConfiguration, BaseScriptConfiguration.Property> CreateQuerySettings()
    {
        return new HierarchicalQuerySettings<BaseScriptConfiguration, BaseScriptConfiguration.Property, BaseScriptQueryChildrenSettings>();
    }
}

public class QuerySettings<T, T1>
{
}

public class HierarchicalQuerySettings<T, T1, T2> : QuerySettings<BaseScriptConfiguration, BaseScriptConfiguration.Property>
{
}

public class BaseScriptQueryChildrenSettings
{
}

public class BaseScriptPageConfiguration
{
    public class Property
    {
    }
}

public class InternalAdminObjectType
{
    public static object BaseScript { get; set; }
}

public class ConfigurationManager
{
}

public class BaseScriptConfiguration
{
    public class Property
    {
    }
}

Answer 3

为ConfigurationList类（例如IConfigurationList）创建一个基本界面，并使用此界面作为变量cl的数据类型，而不是TConfigurationList。

如何在基类使用泛型时隐藏成员函数

3 个答案: