引用型变量和值类型变量在foreach中的区别

对于值类型变量，迭代变量不可更改。 

对于引用型变量，迭代变量可以更改，但是不可以删除。

 

public partial class MainForm : 
    {

        List<int> iNum = new List<int>();

        List<Object> oPerson = new List<object>();

        //foreach--- Reference Type 和  Value Type
        private void simpleButton2_Click(object sender, EventArgs e)
        {
            iNum.Add(1);
            iNum.Add(2);

            Person person1 = new Person();
            person1.Age = 25;
            Person person2 = new Person();
            person2.Age = 26;
            oPerson.Add(person1);
            oPerson.Add(person2);

            //编译时无法通过----错误代码
            foreach (int i in iNum){
                i = 10;
            }

            // 成功修改
            foreach (Person o in oPerson){
                o.Age = 50;
            }
        }
    }
    public class Person
    {
        private int iAge;
        public int Age
        {
            get{return iAge;}
            set{iAge =value;}
        }

    }