Question

我有一个模型和一个窗口的视图模型，我被困在视图中视图的控件具有以下内容：

<TextBlock Text="{Binding Title}" [...] />

数据上下文是视图模型，它具有string类型的Title属性。

问题是，即使值发生变化（我可以通过调试器看到它）并且PropertyChanged调用了Title，TextBlock也不会发生变化（它保持空白。）

为了确认这一点，我实际上每次按下鼠标都会调用更新方法。

我听说有时TextBlock中的绑定被窃听，所以我也试过了一个标签，但它没有用。有什么建议？如果你想看到任何代码，请在评论中告诉我（整件事情都很大）。

ViewModel
Code-behind for the View.

更清楚：Window是我的模特，而不是WPF的窗口！

Answer 1

你的_window.Title是string.Empty。为它分配一些值。喜欢

public WindowViewModel()
{
    Window = new Window(){Title="abc"};
}

更新我尝试了你的代码，但它对我没有用，我做了一个更改，它的工作变化是

public WindowEntryView()
{
    DataContext = new WindowViewModel();
    InitializeComponent();
}

Answer 2

如果您实例化WindowViewModel类

，它会起作用

代码隐藏：

public partial class WindowEntryView
{
    public static readonly DependencyProperty WindowViewModelProperty;
    public WindowViewModel WindowViewModel
    {
        get { return (WindowViewModel)GetValue(WindowViewModelProperty); }
        set
        {
            SetValue(WindowViewModelProperty, value);
            value.Refresh(); // I've putted this out of desperation to see if it would help.. it didn't.
        }
    }

    static WindowEntryView()
    {
        PropertyMetadata metadata = new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.AffectsRender); // Another attempt with no success.
        WindowViewModelProperty = DependencyProperty.Register("WindowViewModel", typeof(WindowViewModel), typeof(WindowEntryView), metadata);
    }

    public WindowEntryView()
    {
        //WindowViewModel = new WindowViewModel(19860522); This is the only attempt that made the label show something, but it didn't update later of course.

        InitializeComponent();

        WindowViewModel = new WpfApplication3.WindowViewModel() { Title = "Check" };
        DataContext = WindowViewModel;
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        WindowViewModel.Title = DateTime.Now.ToString();
    }
}

XAML：

<Grid>
    <TextBlock Text="{Binding Title}" VerticalAlignment="Top"/>
    <Button Content="Button" HorizontalAlignment="Left" Margin="116,131,0,0" VerticalAlignment="Top" Width="75" Click="Button_Click"/>
</Grid>

Answer 3

您能否将属性“Title”中的属性名称传递给OnPropertyChanged方法。

绑定不响应PropertyChanged

3 个答案: