如何知道我们何时完成DataContext？(How to know when we're done with a DataContext?)

如何知道我们何时完成DataContext？(How to know when we're done with a DataContext?)

我目前正在学习WPF和MVVM。

我有一个在我的XAML中使用创建的对话框

<Window.DataContext> <vm:PreferencesViewModel /> </Window.DataContext>

PreferencesViewModel（）的构造函数调用我的PreferencesModel对象的LoadConfig（）（加载XML文件）。 我想要做的是在单击对话框的“确定”按钮时从PreferencesViewModel调用PreferencesModel :: SaveConfig（）但我不能，因为我无法访问由<vm:PreferencesViewModel />自动创建的PreferencesViewModel对象<vm:PreferencesViewModel /> 。 我会在析构函数中执行此操作，但GC不会销毁该对象。

有没有办法知道XAML何时完成了PreferencesViewModel对象？

I'm currently learning WPF and MVVM on my own.

I have a dialog box that is created in my XAML using

<Window.DataContext> <vm:PreferencesViewModel /> </Window.DataContext>

The constructor of PreferencesViewModel() calls the LoadConfig() of my PreferencesModel object (loads a XML file). What I would like to do is call PreferencesModel::SaveConfig() from the PreferencesViewModel when the "OK" button of my dialog box is clicked but I can't since the I don't have access to the PreferencesViewModel object automatically created by <vm:PreferencesViewModel />. I'd do it in the destructor but the GC won't destroy the object.

Is there a way to know when the XAML is done with the PreferencesViewModel object?

最满意答案

...但我不能，因为我无法访问PreferencesViewModel ...

给它一个名字并在codebehind中访问它。

<vm:PreferencesViewModel x:Name="MyVM" />

或者从代码后面的datacontext中提取它：

var myVM = (PreferencesViewModel) DataContext;

...but I can't since the I don't have access to the PreferencesViewModel...

Give it a name and access it in codebehind.

<vm:PreferencesViewModel x:Name="MyVM" />

Or extract it off of the datacontext in code behind:

var myVM = (PreferencesViewModel) DataContext;