如何知道数据绑定源/路径是否有效

Question

我是新的WPF数据绑定。我为数据绑定测试编写了一个小程序。有两个窗户。在Window1.xaml.cs中，

public partial class Window1 : Window, INotifyPropertyChanged
{
    public Window1()
    {
        InitializeComponent();
    }

    public event PropertyChangedEventHandler PropertyChanged;

    string test = "aaa";
    string Test
    {
        get { return test; }
        set { test = value; }
    }

在MainWindow.xaml.cs中，

public partial class MainWindow : Window, INotifyPropertyChanged
{

    public MainWindow()
    {
        InitializeComponent();
        Window1 W1 = new Window1();
        textBlock.DataContext = this;//data-binding source
        textBlock1.DataContext = W1;//data-binding source
    }

    public event PropertyChangedEventHandler PropertyChanged;

    private int a;
    public int A
    {
        get { return a; }
        set { a = value; }
    }

    private void button_Click(object sender, RoutedEventArgs e)
    {
        a++; //why does not it update the value in the UI?
    }
}

最后，在MainWindow.xaml中：

    <Button x:Name="button" Click="button_Click"/>
    <TextBlock x:Name="textBlock" Text="{Binding A}"/>
    <TextBlock x:Name="textBlock1" Text="{Binding Test}"/> //Why does not it work?

当我单击按钮时，我希望更新MainWindow UI，以及从另一个窗口绑定一个字符串类型值"aaa“。但我不知道哪里出了问题。我也不知道是否有一种方法来检查绑定源和路径是否有效。谢谢。

Answer 1

来解决这两个问题。正如Sinatr和Alex提到的，

首先，

public string Test
{
    get { return test; }
    set { test = value; }
}

第二，

public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyname)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null)
        {
            handler(this, new PropertyChangedEventArgs(propertyname));
        }
    }

private void button_Click(object sender, RoutedEventArgs e)
{
    a++; //why does not it update the value in the UI?
    OnPropertyChanged("A");
}