WPF中的INotifyPropertyChanged

Question

尝试了解WPF.这是我的测试类:

    public partial class MainWindow : Window, INotifyPropertyChanged
{
    private ObservableCollection<string> _myList = new ObservableCollection<string>();

    public ObservableCollection<string> MyList
    {
        get { return _myList; }
        set
        {
            _myList = value;
            RaisePropertyChanged("_myList");
        }
    }

    public MainWindow()
    {
        InitializeComponent();
        comboBox1.DataContext = _myList;
    }

    private void button1_Click(object sender, RoutedEventArgs e)
    {
        MyList = AnotherClass.SomeMethod();
    }

    public event PropertyChangedEventHandler PropertyChanged;

    private void RaisePropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

internal static class AnotherClass
{
    public static ObservableCollection<string> SomeMethod()
    {
        return new ObservableCollection<string> {"this","is","test"};
    }
}

这是XAML

<Grid>
    <ComboBox Height="23" HorizontalAlignment="Left" Margin="65,51,0,0" Name="comboBox1" VerticalAlignment="Top" Width="120" ItemsSource="{Binding}" />
    <Button Content="Button" Height="23" HorizontalAlignment="Left" Margin="310,51,0,0" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click" />
</Grid>

如何使这段代码工作？我希望在单击按钮并更新MyList后,ComboBox数据将被更改.PropertyChangedEventHandler始终为null.

Answer 1

问题是你直接将原始列表设置为Window.DataContext,所以没有任何东西听过窗口的PropertyChanged事件.

要解决此问题,请将DataContext窗口设置为:

this.DataContext = this;

然后改变Binding所以参考属性:

<ComboBox ItemsSource="{Binding MyList}" />

你还需要改变你的属性定义,使其提高了的名称属性被更改,该成员的不是名称:

this.RaisePropertyChanged("MyList");