class A
{
    public string Text;
}
class Test:ICloneable
{
    public A a = new A();
      

    public object Clone()
    {
        return this.MemberwiseClone();
    }

     
}

  protected void Page_Load(object sender, EventArgs e)
    {

        Test t = new Test();
        t.a.Text = "A";

        Response.Write(t.a.Text);
        Test t1 = (Test)t.Clone();
        t.a.Text = "B";

        Response.Write(t1.a.Text);
        
    }

------解决方案--------------------

对引用类型字段复制包括它的引用和它的内容
-------------
这一句有点歧义...这里“它的引用”所指向的地址已经不同于源对象的地址了，只是引用的类型相同...