Array.Reverse()方法背后的逻辑

Question

什么是public static void Reverse(Array array,int index,int length)背后的原生逻辑工作;

Answer 1

您可以使用.NET Reflector:

[ReliabilityContract(Consistency.MayCorruptInstance, Cer.MayFail)]
public static void Reverse(Array array, int index, int length)
{
    if (array == null)
    {
        throw new ArgumentNullException("array");
    }
    if ((index < array.GetLowerBound(0)) || (length < 0))
    {
        throw new ArgumentOutOfRangeException((index < 0) ? "index" : "length", Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum"));
    }
    if ((array.Length - (index - array.GetLowerBound(0))) < length)
    {
        throw new ArgumentException(Environment.GetResourceString("Argument_InvalidOffLen"));
    }
    if (array.Rank != 1)
    {
        throw new RankException(Environment.GetResourceString("Rank_MultiDimNotSupported"));
    }
    if (!TrySZReverse(array, index, length))
    {
        int num = index;
        int num2 = (index + length) - 1;
        object[] objArray = array as object[];
        if (objArray == null)
        {
            while (num < num2)
            {
                object obj3 = array.GetValue(num);
                array.SetValue(array.GetValue(num2), num);
                array.SetValue(obj3, num2);
                num++;
                num2--;
            }
        }
        else
        {
            while (num < num2)
            {
                object obj2 = objArray[num];
                objArray[num] = objArray[num2];
                objArray[num2] = obj2;
                num++;
                num2--;
            }
        }
    }
}

TrySZReverse是一种本机方法,有时可以更快地执行相同的操作.