.net 绑定到MVVM中ViewModel中更新的值？

我是MVVM的新手

我的视图中有一个标签如下所示：

<Label Content="{Binding Path=ClockTime}" />

---

我的问题是标签不会随ViewModel中的线程动态更新。有没有简单的方法让视图知道此值是动态的？

您需要在ViewModel中实现INotifyPropertyChanged接口，并在设置时钟时间时引发PropertyChanged事件

您需要在ViewModel中实现INotifyPropertyChanged接口，并在设置时钟时间时引发PropertyChanged事件，以扩展Todd所说的应该像这样更新代码的内容 您需要ViewModelBase看起来像这样

Public class ViewModelBase Inherits INotifyPropertyChanged
  protected Sub OnPropertyChanged(PropertyName as string)
    if PropertyChanged is not nothing then
      PropertyChanged(new PropertyChangedEventArgs(PropertyName)
    end if 
  End Sub
End Class

然后修改视图模型，如下所示：

  Private Sub TimeDelegate(ByVal sender As Object, ByVal e As System.EventArgs)
    ClockTime = DateTime.Now.ToString("dddd, dd MMMM yyyy h:mm:ss tt")
  End Sub

  Public Property ClockTime As String
    Get
      Return strClockTime
    End Get
    Private Set
      strClockTime = value
      OnPropertyChanged("ClockTime")
    End Set
  End Property

---

请注意，我正在分配给ClockTime，当设置完成时，WPF会收到通知，ClockTime已更改，以扩展Todd所说的内容，您应该像这样更新代码 您需要ViewModelBase看起来像这样

Public class ViewModelBase Inherits INotifyPropertyChanged
  protected Sub OnPropertyChanged(PropertyName as string)
    if PropertyChanged is not nothing then
      PropertyChanged(new PropertyChangedEventArgs(PropertyName)
    end if 
  End Sub
End Class

然后修改视图模型，如下所示：

  Private Sub TimeDelegate(ByVal sender As Object, ByVal e As System.EventArgs)
    ClockTime = DateTime.Now.ToString("dddd, dd MMMM yyyy h:mm:ss tt")
  End Sub

  Public Property ClockTime As String
    Get
      Return strClockTime
    End Get
    Private Set
      strClockTime = value
      OnPropertyChanged("ClockTime")
    End Set
  End Property

请注意，我正在分配给ClockTime，当设置时，WPF会被通知ClockTime已更改