c# - 问题复制 C# 枚举器接口(interface)

Question

对于我的项目，我需要复制 C# 枚举器接口(interface)层次结构。我继续从 VS F12 简单地复制&粘贴&重命名:

  public interface IMyEnumerator {
    object Current { get; }
    bool MoveNext();
    void Reset();
  }

  public interface IMyEnumerator<out T> : IMyEnumerator, IDisposable {
    T Current { get; }
  }

  public interface IMyEnumerable {
    IMyEnumerator GetEnumerator();
  }

  public interface IMyEnumerable<out T> : IMyEnumerable {
    IMyEnumerator<T> GetEnumerator();
  }

  public class MyContainer : IMyEnumerable<T>, IMyEnumerable {
    ...
  }
}

我收到关于 IMyEnumerator<out T>.Current 的警告隐藏 IMyEnumerator.Current和 IMyEnumerable<out T>.GetEnumerator隐藏 IMyEnumerable.GetEnumerator建议添加 new关键字。

我应该添加 new 吗？在这种情况下的关键字？我有点不确定其含义，因为 IEnumerator 和 IEnumerable 的匹配源(至少从 VS F12 看)没有 new 关键字，请参阅:

namespace System.Collections {
  //
  // Summary:
  //     Supports a simple iteration over a non-generic collection.
  public interface IEnumerator {
    //
    // Summary:
    //     Gets the element in the collection at the current position of the enumerator.
    //
    // Returns:
    //     The element in the collection at the current position of the enumerator.
    object Current { get; }

    //
    // Summary:
    //     Advances the enumerator to the next element of the collection.
    //
    // Returns:
    //     true if the enumerator was successfully advanced to the next element; false if
    //     the enumerator has passed the end of the collection.
    //
    // Exceptions:
    //   T:System.InvalidOperationException:
    //     The collection was modified after the enumerator was created.
    bool MoveNext();
    //
    // Summary:
    //     Sets the enumerator to its initial position, which is before the first element
    //     in the collection.
    //
    // Exceptions:
    //   T:System.InvalidOperationException:
    //     The collection was modified after the enumerator was created.
    void Reset();
  }
  //
  // Summary:
  //     Exposes an enumerator, which supports a simple iteration over a non-generic collection.
  public interface IEnumerable {
    //
    // Summary:
    //     Returns an enumerator that iterates through a collection.
    //
    // Returns:
    //     An System.Collections.IEnumerator object that can be used to iterate through
    //     the collection.
    IEnumerator GetEnumerator();
  }
}

namespace System.Collections.Generic {
  //
  // Summary:
  //     Supports a simple iteration over a generic collection.
  //
  // Type parameters:
  //   T:
  //     The type of objects to enumerate.
  public interface IEnumerator<out T> : IEnumerator, IDisposable {
    //
    // Summary:
    //     Gets the element in the collection at the current position of the enumerator.
    //
    // Returns:
    //     The element in the collection at the current position of the enumerator.
    T Current { get; }
  }

  //
  // Summary:
  //     Exposes the enumerator, which supports a simple iteration over a collection of
  //     a specified type.
  //
  // Type parameters:
  //   T:
  //     The type of objects to enumerate.
  public interface IEnumerable<out T> : IEnumerable {
    //
    // Summary:
    //     Returns an enumerator that iterates through the collection.
    //
    // Returns:
    //     An enumerator that can be used to iterate through the collection.
    IEnumerator<T> GetEnumerator();
  }
}

Answer 1

如果您引用源代码，您会看到 IEnumerator<T>实际上使用 new关键词:

public interface IEnumerator<out T> : IDisposable, IEnumerator
{
    // Returns the current element of the enumeration. The returned value is
    // undefined before the first call to MoveNext and following a
    // call to MoveNext that returned false. Multiple calls to
    // GetCurrent with no intervening calls to MoveNext
    // will return the same object.
    new T Current
    {
        get;
    }
}

来源:

• .NET Framework IEnumerator<T>
• .NET Framework IEnumerator
• .NET Core IEnumerator<T>
• .NET Core IEnumerator