Csharp 如何在CommunityToolkit.Mvvm的ObservableObject中绑定到Task<T>

你必须等Task号.你的例子不是与Task的结果绑定，而是与Task.Status的结果绑定.为了绑定到结果，你必须await Task对象.

为此，您可以定义一个异步命令:

[RelayCommand]
private async Task RequestValueAsync()
{
  RequestTask = await LoadAsync();
}

private int requestTask;
public int RequestTask
{
  get => requestTask;
  private set => SetProperty(ref requestTask, value);
}

private async Task<int> LoadAsync()
{
  await Task.Delay(3000);
  return 5;
}

<Window>
    <Window.DataContext>
        <local:MainWindowViewModel/>
    </Window.DataContext>
    <StackPanel>
        <Button Command="{Binding RequestValueCommand}" Content="Get my value"/>
        <StackPanel Orientation="Horizontal" >
            <TextBlock Text="My value is:"/>
            <TextBlock Text="{Binding RequestTask}"/>
        </StackPanel>
    </StackPanel>
</Window>

If for what reason ever you insist in using TaskNotifier to bind to "async" properties (an asynchronous property is an oxymoron) you simply bind to the property as usual. The TaskNotifier will unwrap the result.
Because asynchronous code implies to be longrunning you should also set Binding.IsAsync to true on the particular Binding:

<Window>
    <Window.DataContext>
        <local:MainWindowViewModel/>
    </Window.DataContext>
    <StackPanel>
        <Button Command="{Binding RequestValueCommand}" Content="Get my value"/>
        <StackPanel Orientation="Horizontal" >
            <TextBlock Text="My value is:"/>
            <TextBlock Text="{Binding RequestTask.Result, IsAsync=True}"/>
        </StackPanel>
    </StackPanel>
</Window>