双向绑定一个实现INotifyPropertyChanged的类，什么都不会发生

本文关键字：什么 的类 INotifyPropertyChanged 实现 绑定 一个 | 更新日期: 2023-09-27 17:54:41

我在微软网站上遵循了几个例子，第一个涉及ItemsSource:

ItemsControl。ItemsSource财产第二:

如何:实现属性更改通知

合并在一起的两个例子，我已经到达我的例子:

XAML 

<Window x:Class="WpfSchede.Test.ItemsSourceTest"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:c="clr-namespace:WpfSchede.Test"
    Title="ItemsSourceTest" Height="352" Width="467">
<Window.Resources>
    <c:NameList x:Key="NameListData"></c:NameList>
    <DataTemplate x:Key="NameItemTemplate">
        <TextBlock Width="200" Text="{Binding Path=FullName, Mode=TwoWay}" />
    </DataTemplate>
</Window.Resources>                   
<Grid>
    <ListBox ItemsSource="{Binding Source={StaticResource NameListData}}" ItemTemplate="{StaticResource NameItemTemplate}" Margin="12,12,120,65" Name="listBoxNames" IsSynchronizedWithCurrentItem="True"> 
    </ListBox>
    <Button Content="Change First Name" Height="23" HorizontalAlignment="Left" Margin="12,270,0,0" Name="buttonChangeName" VerticalAlignment="Top" Width="163" Click="buttonChangeName_Click" />
    <Button Content="Change Full Name" Height="23" HorizontalAlignment="Left" Margin="193,270,0,0" Name="buttonChangeFullName" VerticalAlignment="Top" Width="163" Click="buttonChangeFullName_Click" />
</Grid>

XAML.CS 

using System.Windows;
namespace WpfSchede.Test
{
public partial class ItemsSourceTest : Window
{
    public ItemsSourceTest()
    {
        InitializeComponent();
    }
    private void buttonChangeName_Click(object sender, RoutedEventArgs e)
    {
        PersonName p = listBoxNames.SelectedItem as PersonName;
        p.FirstName = "Andrew";
    }
    private void buttonChangeFullName_Click(object sender, RoutedEventArgs e)
    {
        PersonName p = listBoxNames.SelectedItem as PersonName;
        p.FullName = "Andrea Rossi";
    }
  }
}
<<p> 名称表类/strong> 
using System.Collections.ObjectModel;
using System.ComponentModel;
namespace WpfSchede.Test
{
public class NameList : ObservableCollection<PersonName>
{
    public NameList()
        : base()
    {
        Add(new PersonName("Wil", "Cath"));
        Add(new PersonName("Isak", "Dinesen"));
        Add(new PersonName("Victor", "Hugo"));
        Add(new PersonName("Jules", "Verne"));
        Add(new PersonName("Leonardo", "Rossi"));
    }
}
public class PersonName : INotifyPropertyChanged 
{
    private string firstName;
    private string lastName;
    // Define the event
    public event PropertyChangedEventHandler PropertyChanged; 
    public PersonName(string first, string last)
    {
        this.firstName = first;
        this.lastName = last;
    }
    public string FirstName
    {
        get { return firstName; }
        set { 
            firstName = value; 
            OnPropertyChanged(value);
        }
    }
    public string LastName
    {
        get { return lastName; }
        set { lastName = value; }
    }
    public string FullName
    {
        set {
            string full = value as string;
            char[] sep = { ' ' };
            string[] n = full.Split(sep);
            this.FirstName = n[0];
            this.LastName = n[1];
            OnPropertyChanged(value);
        }
        get { return firstName + " " + lastName; }
    }
    protected void OnPropertyChanged(string name)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null)
        {
            handler(this, new PropertyChangedEventArgs(name));
        }
    }
 }
}

我有两个问题

第一)当点击其中一个按钮时，我期待列表框反映的变化，而不是什么都没有发生!我错过了什么?

第二)在DataTemplate中，我绑定到FullName(仅绑定到FirstName对于示例来说更容易，但对我来说似乎太简化了)。因此，我选择绑定到一个属性FullName，为此我在NameList类和DataTemplate代码中编写了自定义代码。我的代码有什么问题?在DataTemplate中指定Mode=TwoWay是正确的吗?

双向绑定一个实现INotifyPropertyChanged的类，什么都不会发生

OnPropertyChanged(value);是错误的

应该是OnPropertyChanged("FirstName");并且后面还应该跟着OnPropertyChanged("FullName");导致

OnPropertyChanged("FirstName");
OnPropertyChanged("FullName");

LastName设置函数应该有

OnPropertyChanged("LastName");
OnPropertyChanged("FullName");

和finally set函数应该有

OnPropertyChanged("FullName");
OnPropertyChanged("FirstName");
OnPropertyChanged("LastName");
相关文章：