你可以尝试这样的事情。以下代码假定 Windows 窗体包含一个名为 mainListBox 的列表框、一个名为 upButton 的按钮和一个名为 downButton 的按钮。
public partial class Form1 : Form
{
private class Person
{
public string LastName { get; set; }
public string FirstName { get; set; }
public override string ToString()
{
return string.Format("{0}, {1}", LastName, FirstName);
}
}
public Form1()
{
this.InitializeComponent();
this.mainListBox.SelectionMode = SelectionMode.One;
this.PopulateListBox();
}
private void PopulateListBox()
{
this.mainListBox.Items.Add(new Person() { FirstName = "Joe", LastName = "Smith" });
this.mainListBox.Items.Add(new Person() { FirstName = "Sally", LastName = "Jones" });
this.mainListBox.Items.Add(new Person() { FirstName = "Billy", LastName = "Anderson" });
}
private void upButton_Click(object sender, EventArgs e)
{
if (this.mainListBox.SelectedIndex > 0)
{
int selectedIndex = this.mainListBox.SelectedIndex;
object selectedItem = this.mainListBox.SelectedItem;
this.mainListBox.Items.RemoveAt(selectedIndex);
this.mainListBox.Items.Insert(selectedIndex - 1, selectedItem);
this.mainListBox.SelectedIndex = selectedIndex - 1;
}
}
private void downButton_Click(object sender, EventArgs e)
{
if (this.mainListBox.SelectedIndex > -1 &&
this.mainListBox.SelectedIndex < this.mainListBox.Items.Count - 1)
{
int selectedIndex = this.mainListBox.SelectedIndex;
object selectedItem = this.mainListBox.SelectedItem;
this.mainListBox.Items.RemoveAt(selectedIndex);
this.mainListBox.Items.Insert(selectedIndex + 1, selectedItem);
this.mainListBox.SelectedIndex = selectedIndex + 1;
}
}
}
仅当您使用 ObjectCollection.Add 方法将项目添加到 ListBox 时,此方法才有效。如果是数据绑定,可以更新实际的数据源,使用ListBox的BindingContext来刷新。
private List<Person> people = new List<Person>();
private void PopulateListBox()
{
this.people.Add(new Person() { FirstName = "Joe", LastName = "Smith" });
this.people.Add(new Person() { FirstName = "Sally", LastName = "Jones" });
this.people.Add(new Person() { FirstName = "Billy", LastName = "Anderson" });
this.mainListBox.DataSource = people;
}
private void upButton_Click(object sender, EventArgs e)
{
if (this.mainListBox.SelectedIndex > 0)
{
int selectedIndex = this.mainListBox.SelectedIndex;
Person selectedItem = this.mainListBox.SelectedItem as Person;
this.people.RemoveAt(selectedIndex);
this.people.Insert(selectedIndex - 1, selectedItem);
this.mainListBox.SelectedIndex = selectedIndex - 1;
this.RefreshListSource();
}
}
private void RefreshListSource()
{
CurrencyManager boundList = this.mainListBox.BindingContext[this.people] as CurrencyManager;
boundList.Refresh();
}