public static void NonRefArray(object[] a)
{
    a[1] = 2;
    a = new object[] { 3, 3, 3 };
}
public static void RefArray(ref object[] a)
{
    a[1] = 2;
    a = new object[] { 3, 3, 3 };
}
static void Main(string[] args)
{
    object[] a = new object[] { 1, 1, 1, 1 };
    NonRefArray(a);
    Console.WriteLine(String.Join(", ", a));
    RefArray(a);
    Console.WriteLine(String.Join(", ", a));
}

------解决方案--------------------
C# code

// 修改一下：
public static void NonRefArray(object[] a)
{
    a[1] = 2;
    a = new object[] { 3, 3, 3 };
}
public static void RefArray(ref object[] a)
{
    a[1] = 2;
    a = new object[] { 3, 3, 3 };
}
static void Main(string[] args)
{
    object[] a = new object[] { 1, 1, 1, 1 };
    NonRefArray(a);
    Console.WriteLine(String.Join(", ", a));
    RefArray(ref a); // 调用加 ref 关键字
    Console.WriteLine(String.Join(", ", a));
}