c# - 将 Last 属性添加到 System.Array 的最佳方法是什么？

Question

我尝试了下面的解决方案，但我不喜欢它。我正在寻找扩展类，而不是封装 double[]。

谢谢。

编辑:我们需要使用 .NET 2.0

public class DoubleArray : IList, ICloneable
{

    protected double[] items;

    /// <summary>
    /// Gets the last item in the array.
    /// </summary>
    public double Last { get { return items[items.Length-1]; } }

    /// <summary>
    /// Gets the number of items in the array.
    /// </summary>
    public int Length { get { return items.Length; } }

    /// <summary>
    /// Number of items constructor.
    /// </summary>
    /// <param name="len">Number of items</param>
    public DoubleArray(int len)
    {
        items = new double[len];
    }      

    public double this[int index]
    {
        get { return items[index]; }
        set { items[index] = value; }
    }

    public bool IsReadOnly
    {
        get { return items.IsReadOnly; }
    }

    public bool IsFixedSize
    {
        get { return items.IsFixedSize; }
    }

    public void CopyTo(Array array, int index)
    {
        items.CopyTo(array, index);
    }

    public IEnumerator GetEnumerator()
    {
        return items.GetEnumerator();
    }

    public object SyncRoot
    {
        get { return items.SyncRoot; }
    }

    public bool IsSynchronized
    {
        get { return items.IsSynchronized; }
    }

    object ICloneable.Clone()
    {
        return items.Clone();
    }

    #region ICollection and IList members implementation

    // hides this members from intellisense, see: http://stackoverflow.com/questions/10110205/how-does-selectedlistviewitemcollection-implement-ilist-but-not-have-add

    int ICollection.Count
    {
        get { return items.Length; }
    }

    int IList.Add(object value)
    {
        throw new NotImplementedException();
    }

    bool IList.Contains(object value)
    {
        throw new NotImplementedException();
    }

    void IList.Clear()
    {
        throw new NotImplementedException();
    }

    int IList.IndexOf(object value)
    {
        throw new NotImplementedException();
    }

    void IList.Insert(int index, object value)
    {
        throw new NotImplementedException();
    }

    void IList.Remove(object value)
    {
        throw new NotImplementedException();
    }

    void IList.RemoveAt(int index)
    {
        throw new NotImplementedException();
    }

    object IList.this[int index]
    {
        get { throw new NotImplementedException(); }
        set { throw new NotImplementedException(); }
    } 

    #endregion

}

Answer 1

你不能使用 LINQ 并调用

array.Last()

? (.NET 3.5 及更高版本和“使用 System.Linq；”)

.NET 2 解决方案:(将触发 IndexOutOfRange exc. 在 Count == 0 的情况下)

public class MyList<T> : List<T>
{
    public T Last
    {
        get
        {
             return this[this.Count - 1];
        }
    }
}