c# - INotifyPropertyChanged 不适用于传统绑定(bind)，但适用于编译绑定(bind)

Question

如果我做错了什么或者我遗漏了什么，我不会这样做，但是当我使用编译时绑定(bind)时 INotifyPropertyChanged 起作用，而当我使用传统绑定(bind)时它不起作用。

public class Students : INotifyPropertyChanged
{

    private string name;
    private string surname;


    public event PropertyChangedEventHandler PropertyChanged;

    private void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    public string Name
    {
        get { return name; }
        set
        {
            if(value != name)
            {
                name = value;
                NotifyPropertyChanged();
            }

        }
    }

    public string Surname
    {
        get { return surname; }
        set
        {
            if (value != surname)
            {
                surname = value;
                NotifyPropertyChanged();
            }

        }
    }

    public Students()
    {
        Name = "John";
        Surname = "Smith";
    }


}

主页.xaml

<Page.DataContext>
    <local:Students/>
</Page.DataContext>

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

    <StackPanel Margin="0,200,0,0">
        <TextBlock Text="{Binding Name}"/>
        <TextBlock Text="{Binding Surname}"/>
        <Button Content="Change Name" Click="change_name"/>
        <Button Content="Change Surname" Click="change_surname"/>
    </StackPanel>

</Grid>

MianPage.xaml.cs

public sealed partial class MainPage : Page
{
    Students st;
    public MainPage()
    {
        this.InitializeComponent();
        st = new Students();
    }

    private void change_name(object sender, RoutedEventArgs e)
    {
        st.Name = "MM";
    }

    private void change_surname(object sender, RoutedEventArgs e)
    {
        st.Surname = "SS";
    }
}

我真的很困惑，因为当你使用编译时绑定(bind)进行绑定(bind)时，它工作正常。怎么回事？

Answer 1

我没有看到您将当前 DataContext 设置为您的对象的任何地方。

 public MainPage()
    {
        this.InitializeComponent();
        st = new Students();
        this.DataContext = st;
    }

或:您正在 XAML 中设置数据上下文，但未引用它。

<Page.DataContext>
<local:Students/>
</Page.DataContext>

如果您打算使用它，则需要从代码中引用该对象。

 private void change_name(object sender, RoutedEventArgs e)
    {
        ((Students)this.DataContext).Name = "MM";
    }