跨未装箱变量传播更改

我只是做了一个小实验，看看改变一个未装箱的变量是否会传播对原始源代码所做的更改，并根据我使用的类型得到了两个完全不同的结果。我主要感兴趣的是为WPF数据绑定应用程序弄清楚这一点，在这些应用程序中，我绑定到object、转换、更改，并希望原始的更新它们的ui。

结果如下:

1. 简单类型在拆箱后似乎失去了对原始源的引用。
自定义类型似乎保留了它们的引用。

似乎我没有什么可担心的，在我的情况下，希望我的WPF UI更新自己后对未装箱绑定的数据上下文进行更改;然而，不知道为什么这种情况只发生在复杂的对象上，这让我有点担心。我不希望我的UI在我不知道的罕见或奇怪的情况下失败。有人能解释一下后面发生的机械现象吗?

class Program
{
    //simple types
    private static object sbox1;
    private static object sbox2;
    private static int svalue1 = 10;
    private static int svalue2 = 15;
    //custom types
    private static MyType cvalue1;
    private static MyType cvalue2;
    private static object cbox1;
    private static object cbox2;
    static void Main(string[] args)
    {
        //Box up the values
        sbox1 = svalue1;
        sbox2 = svalue2;
        //unbox the values to local var
        var sunboxed1 = (int)sbox1;
        var sunboxed2 = (int)sbox2;
        //change the values in the new unboxed vars
        sunboxed1 = -10;
        sunboxed2 = -15;
        //check unboxed values and check original value variables
        Console.WriteLine("unboxed1 = " + sunboxed1);
        Console.WriteLine("unboxed2 = " + sunboxed2);
        Console.WriteLine("value1 = " + svalue1);
        Console.WriteLine("value2 = " + svalue2);
        //Now try hand at custom types
        cvalue1 = new MyType() { Example = "I am cvalue1's original string." };
        cvalue2 = new MyType() { Example = "I am cvalue2's original string." };
        //now box them up.
        cbox1 = cvalue1;
        cbox2 = cvalue2;
        //now unbox and change the strings
        var cunboxed1 = cbox1 as MyType;
        var cunboxed2 = cbox2 as MyType;
        //change the original strings to see if they propogate to original objects
        cunboxed1.Example = "I am cunboxed1's altered string.";
        cunboxed2.Example = "I am cunboxed2's altered string.";
        //print unboxed and originals values to compare
        Console.WriteLine("cunboxed1.Example = " + cunboxed1.Example);
        Console.WriteLine("cunboxed2.Example = " + cunboxed2.Example);
        Console.WriteLine("cvalue1.Example = " + cvalue1.Example);
        Console.WriteLine("cvalue2.Example = " + cvalue2.Example);
        Console.ReadKey();
    }
}
class MyType
{
    public string Example { get; set; }
}

测试程序的结果:

unboxed1 = -10  
unboxed2 = -15  
value1 = 10  
value2 = 15  
cunboxed1.Example = I am cunboxed1's altered string.  
cunboxed2.Example = I am cunboxed2's altered string.  
cvalue1.Example = I am cunboxed1's altered string.  
cvalue2.Example = I am cunboxed2's altered string.