Silverlight View 通过 MEF 将 DependencyProperty 导出到 ViewModel

发布于 2024-10-05 08:54:56 字数 1403 浏览 2 评论 0原文

我需要 ViewModel 构造函数中的视图中的一个 DependencyProperty：

我的问题：MEF 不会 SatisfyImports() '因为它标记有一个或多个 ExportAttributes' （这是例外）

这是 VIEW 的代码结构：

public class MyView : UserControl
{
    [Export(MethodTypes.ChartType)]
    public Charts MyChartType
    {
        get
        {
            object k = GetValue(ChartTypeProperty);
            Charts f = (Charts)Enum.Parse(typeof(Charts), k.ToString(), true);
            return f;
        }
        set
        {
            SetValue(ChartTypeProperty, value);
        }
    }

    [Import(ViewModelTypes.GenericChartViewModel)]
    public object ViewModel
    {
        set
        {
            DataContext = value;
        }
    }

    public MyView()
    {
        InitializeComponent();

        if (!ViewModelBase.IsInDesignModeStatic)
        {
            // Use MEF To load the View Model
            CompositionInitializer.SatisfyImports(this);
        }
    }
}

和 VIEWMODEL：

[PartCreationPolicy(CreationPolicy.NonShared)]
[Export(ViewModelTypes.GenericChartViewModel)]
public class GenericChartViewModel
{
    [ImportingConstructor]
    public GenericChartViewModel([Import(MethodTypes.ChartType)] Charts forChartType)
    {
        string test = forChartType.ToString();
    }
}

请给我任何提示，或者建议通过 mef 传递参数的更好解决方案。

在我的情况下，我现在只需要传递 dependentecyproperty...

谢谢

原文

I have a need of one DependencyProperty from a View in my ViewModel constructor:

My problem: MEF wouldn't SatisfyImports() 'because it is marked with one or more ExportAttributes' (that is the exception)

This is the code structure for the VIEW:

public class MyView : UserControl
{
    [Export(MethodTypes.ChartType)]
    public Charts MyChartType
    {
        get
        {
            object k = GetValue(ChartTypeProperty);
            Charts f = (Charts)Enum.Parse(typeof(Charts), k.ToString(), true);
            return f;
        }
        set
        {
            SetValue(ChartTypeProperty, value);
        }
    }

    [Import(ViewModelTypes.GenericChartViewModel)]
    public object ViewModel
    {
        set
        {
            DataContext = value;
        }
    }

    public MyView()
    {
        InitializeComponent();

        if (!ViewModelBase.IsInDesignModeStatic)
        {
            // Use MEF To load the View Model
            CompositionInitializer.SatisfyImports(this);
        }
    }
}

and the VIEWMODEL:

[PartCreationPolicy(CreationPolicy.NonShared)]
[Export(ViewModelTypes.GenericChartViewModel)]
public class GenericChartViewModel
{
    [ImportingConstructor]
    public GenericChartViewModel([Import(MethodTypes.ChartType)] Charts forChartType)
    {
        string test = forChartType.ToString();
    }
}

Please give me any hints on this or maybe suggest a better solution for passing parameters through mef

In my case, I would need to pass only dependecyproperty's for now...

Thanks

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花开柳相依 2024-10-12 08:54:56

您的解决方法并不是很好。您不能从 ChartTypes 中删除导出并将其手动传递给想要的人吗？我认为视图模型只是一个对此感兴趣的人。

回复收藏 0 原文

無心 2024-10-12 08:54:56

我成功地做到了！

我使用：而不是默认构造函数中的代码，

    void MyView_Loaded(object sender, RoutedEventArgs e)
    {
        if (!ViewModelBase.IsInDesignModeStatic)
        {
            var catalog = new TypeCatalog(typeof(GenericChartViewModel));
            var container = new CompositionContainer(catalog);

            container.ComposeParts(this);
        }
    }

并且 dependencyproperty 值已正确传播到 ViewModel
（必须在加载控件后执行此操作，否则该属性将具有默认值）

但是，如果有人可以：

谢谢

I managed to put this through !

Instead of the code in the default constructor, I use:

    void MyView_Loaded(object sender, RoutedEventArgs e)
    {
        if (!ViewModelBase.IsInDesignModeStatic)
        {
            var catalog = new TypeCatalog(typeof(GenericChartViewModel));
            var container = new CompositionContainer(catalog);

            container.ComposeParts(this);
        }
    }

and the dependencyproperty value is correctly propagated to the ViewModel
(must do this after control is loaded, or the property will have its default value)

However, I would be very grateful if someone could: