reflection - 为什么反射不在Struct中设置属性？

Question

   class PriceClass {

        private int value;
        public int Value
        {
            get { return this.value; }
            set { this.value = value; }
        }           
    }


    struct PriceStruct
    {

        private int value;
        public int Value
        {
            get { return this.value; }
            set { this.value = value; }
        }
    }
    static void Main(string[] args)
    {
        PriceClass _priceClass = new PriceClass();
        Type type = typeof(PriceClass);
        PropertyInfo info = type.GetProperty("Value");
        info.SetValue(_priceClass, 32, null);
        Console.WriteLine(_priceClass.Value);

        PriceStruct _priceStruct = new PriceStruct();
        type = typeof(PriceStruct);
        info = type.GetProperty("Value");
        info.SetValue(_priceStruct, 32, null);
        Console.WriteLine(_priceStruct.Value);

        Debugger.Break();
    }

打印的第一个值是32，第二个值是0。不会引发异常

Answer 1

这是因为对结构进行装箱会对其进行复制，因此您应该更早对它进行装箱，以便从修改后的相同数据中调用 setter/getter 。以下代码有效:

    object _priceStruct = new PriceStruct(); //Box first
    type = typeof(PriceStruct);
    info = type.GetProperty("Value");
    info.SetValue(_priceStruct, 32, null);
    Console.WriteLine(((PriceStruct)_priceStruct).Value); //now unbox and get value

    Debugger.Break();