WPF中的INotifyPropertyChanged

Question

嘗試了解WPF。 這是我的測試類：

    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"};
    }
}

這是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>

如何使這段代碼工作？ 我希望在單擊按鈕並更新MyList后，ComboBox數據將被更改。 PropertyChangedEventHandler始終為null。

Answer 1

問題是你是直接將原始列表設置到Window.DataContext ，所以沒有任何東西可以監聽windows的PropertyChanged事件。

要解決此問題，請將DataContext設置為窗口本身：

this.DataContext = this;

然后更改Binding所以請參閱屬性：

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

你還需要改變你的屬性定義，這樣它提出要更改的屬性的名稱，該成員的不是名稱：

this.RaisePropertyChanged("MyList");

Answer 2

我認為你有兩個問題：

1）綁定應該是： {Binding MyList}

2）在RaisePropertyChanged("MyList"); setter上你應該使用RaisePropertyChanged("MyList");