static void Main(string[] args) {
Fruit f = new Fruit() {
Weight = 1,
Color = ""
};
Change(ref f);
//把引用对象作为参数传进一个方法，实际上是在栈上新分配了一块内存保存传入的地址
WriteLine(f.Weight); //output is 2
}
static void Change(ref Fruit f)
{
f.Weight = 2;
f = new Fruit() { Weight = 3 };
}
https://www.cnblogs.com/lwzz/archive/2012/03/11/2390589.html