鉴于这一法典,我无法理解以下两个问题。 我将一个 com子描绘成一个定制物体,我每次都希望 com子上选定的价值变化,习惯也反对改变。

public partial class MainForm : Form
{
    private Person _person;
    public MainForm()
    {
        InitializeComponent();
        _person = new Person();

        //Populating the combox, we have this.comboBoxCities.DataSource = this.cityBindingSource;
        cityBindingSource.Add(new City("London"));
        cityBindingSource.Add(new City("Paris"));
        _person.BirthCity = new City("Roma");
        cityBindingSource.Add(_person.BirthCity);
        cityBindingSource.Add(new City("Madrid"));

        //Doing the binding
        comboBoxCities.DataBindings.Add("SelectedItem", _person, "BirthCity");
    }

    private void buttonDisplay_Click(object sender, EventArgs e)
    {
        MessageBox.Show("BirthCity=" + _person.BirthCity.Name);
    }

    private int i = 0;
    private void buttonAddCity_Click(object sender, EventArgs e)
    {
        City city = new City("City n°" + i++);
        cityBindingSource.Add(city);
        comboBoxCities.SelectedItem = city;
    }

}

public class Person
{
    private City _birthCity;
    public City BirthCity
    {
        get { return _birthCity; }
        set
        {
            Console.WriteLine("Setting birthcity : " + value.Name);
            _birthCity = value;
        }
    }
}

public class City
{
    public string Name { get; set; }
    public City(string name) { Name = name; }
    public override string ToString() { return Name; }
}

1 - 为什么我用手工方式在一行(或更长时间)中选择了两 value子的不同价值,我只听说生育间隔。 他必须掌握最后选定的价值(而电话似乎只是在 com子失去重点时才发射)?

2 - 因此,当我点击纽顿AddCity和随后又点击Display时,被淡化的城市不是被选择的(不是在 como箱中展示的)城市。