ContentControl中没有更新 [英] ContentControl not updating

问题描述

我想有一个绑定到一个视图中的主窗口。我更改代码视图，并期待它在主窗口更新，但是这没有发生。

我有这样的代码在我的XAML

<预类=郎咸平的XML prettyprint-覆盖> <网格和GT;
< ContentControl中CONTENT ={绑定源= {StaticResource的ViewModelLocator}，路径= MainWindowViewModel.CurrentControl}/>
< /网格和GT;


然后我通过这段代码

改变我的控制<前类=郎-CS prettyprint-覆盖> 公共类MainWindowViewModel：ReactiveObject
{
私人用户控件_CurrentControl = NULL;
公众用户控件CurrentControl
{
得到
{
如果（_CurrentControl == NULL）
{
_CurrentControl =新的主页（）;
}
返回_CurrentControl;
}
组
{
this.RaiseAndSetIfChanged（X => x.CurrentControl，价值）;
}
}
}


正如你可以看到我'使用ReactiveUI库米

是 ContentControl中做错事在该视图中使用还是我只是不具约束力和更新是否正确？

解决方案

有实际上是一个更好的办法做到这一点，使用 ViewModelViewHost ：

 <电网的DataContext ={绑定视图模型，的ElementName = TheUserControl}> 
< ViewModelViewHost视图模型={结合CurrentControlViewModel}/> 
< /网格和GT; 
  

现在，您的类看起来是这样的：

 公共类MainWindowViewModel：ReactiveObject 
 {
私人ReactiveObject _CurrentControlViewModel =新HomePageViewModel（）; 
公共ReactiveObject CurrentControlViewModel {
 {返回_CurrentControl; } 
集合{this.RaiseAndSetIfChanged（X => x.CurrentControlViewModel，价值）; } 
} 
} 
  

和地方在你的应用程序的启动，你应该写

  RxApp.Register（typeof运算（IViewFor< HomePageViewModel>）的typeof（主页））; 
  

什么是ViewModelViewHost？

ViewModelViewHost 将带您通过绑定提供一个视图模型对象，而查找的适合它，使用服务定位视图。该注册电话是怎么可以关联与次的ViewModels

I'm trying to have a MainWindow that is bound to the a view. I change that view in code and expect it to update in the Main Window, however that is not happening.

I have this code in my XAML

<Grid>
    <ContentControl Content="{Binding Source={StaticResource ViewModelLocator}, Path=MainWindowViewModel.CurrentControl}" />
</Grid>

I then change my Control via this code

public class MainWindowViewModel : ReactiveObject
{
    private UserControl _CurrentControl = null;
    public UserControl CurrentControl
    {
        get
        {
            if (_CurrentControl == null)
            {
                _CurrentControl = new HomePage();
            }
            return _CurrentControl;
        }
        set
        {
            this.RaiseAndSetIfChanged(x => x.CurrentControl, value);
        }
    }
}

As you can see I'm using the ReactiveUI library.

Is ContentControl the wrong thing to use in that view or am I just not binding and updating correctly?

解决方案

There is actually a far better way to do this, using ViewModelViewHost:

<Grid DataContext="{Binding ViewModel, ElementName=TheUserControl}">
    <ViewModelViewHost ViewModel="{Binding CurrentControlViewModel}" />
</Grid>

Now, your class will look something like:

public class MainWindowViewModel : ReactiveObject
{
    private ReactiveObject _CurrentControlViewModel = new HomePageViewModel();
    public ReactiveObject CurrentControlViewModel {
        get { return _CurrentControl; }
        set { this.RaiseAndSetIfChanged(x => x.CurrentControlViewModel, value); }
    }
}

And somewhere in your app's startup, you should write:

RxApp.Register(typeof(IViewFor<HomePageViewModel>), typeof(HomePage));

What's ViewModelViewHost?

ViewModelViewHost will take a ViewModel object that you provide via Bindings, and look up a View that fits it, using Service Location. The Register call is how you can associate Views with ViewModels.

这篇关于ContentControl中没有更新的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！