从不同的C#类访问列表对象

Question

我正在尝试锻炼以了解如何从不同的类访问列表项并更新它们,我在下面的代码中进行了澄清.

class list
{
    private List<Person> people;
    public List<Person> People
    {
       get { return people; }
       set { people = value; }
    }
}

public partial class Form2 : Form
{
    Person p = new Person();
    list l = new list();

    p.Name = textBox1.Text;
    p.Streetaddress = textBox2.Text;
    p.Email = textBox3.Text;
    p.Birthday = dateTimePicker1.Value;
    p.AdditionalNotes = textBox4.Text;

    l.People.Add(p);
    listView2.Items.Add(p.Name);
}

有Person类,它有实例变量Name,Streetaddress等.

得到一个错误

Nullreference异常未得到处理

请帮我..

Answer 1

在实例化List<Person>List类时,需要实例化内部.否则它将为null.

class list
{

   private List<Person> people = new List<Person>();
   public List<Person> People
   {
       get { return people; }
       set { people = value;}
   }

}