Question

我想在子窗口中使用View Model Locator。问题是这不起作用：

<controls:ChildWindow x:Class="Views.PopupViews.AddAlert"
       xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
       xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
       xmlns:controls="clr namespace:System.Windows.Controls;assembly=System.Windows.Controls"
       DataContext="{Binding AddAlert, Source={StaticResource Locator}}>

我收到错误： 找不到名称/密钥定位器的资源

Answer 1

使用定位器模式将子窗口绑定到静态视图模型没有任何技巧。我的猜测是你的DataContext错了。

检查：确保在定位器类中定义了“AddAlert”属性。类似的东西：

    private static AddAlertViewModel _AddAlertViewModel;

    /// <summary>
    /// Gets the ViewModelPropertyName property.
    /// </summary>
    public static AddAlertViewModel AddAlertViewModelStatic
    {
        get
        {
            if (_AddAlertViewModel == null)
            {
                CreateAddAlertViewModel();
            }

            return _AddAlertViewModel;
        }
    }

    /// <summary>
    /// THIS PROPERTY IS WHAT YOU NEED TO REFERENCE IN YOUR XAML
    /// </summary>
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1822:MarkMembersAsStatic", Justification = "This non-static member is needed for data binding purposes.")]
    public AddAlertViewModel AddAlert
    {
        get
        {
            return AddAlertViewModelStatic;
        }
    }

当然，请确保您的视图模型定位器在App.xaml文件中实例化：

  <vm:MyModelLocator xmlns:vm="clr-namespace:MyAppNamespace" x:Key="Locator" />

Answer 2

好的，它无法工作的原因是我的childWindow是在IApplicationService的ctor中创建的。

此popupService在App.xaml中声明：

<Application.Resources>
    <ResourceDictionary>
        <vm:ViewModelLocator xmlns:vm="clr-namespace:Client.ViewModel" x:Key="Locator" />
        <ResourceDictionary.MergedDictionaries>
            <ResourceDictionary Source="Assets/Styles.xaml"/>
        </ResourceDictionary.MergedDictionaries>
    </ResourceDictionary>
</Application.Resources>
<Application.ApplicationLifetimeObjects>
    <popup:myPopupService/>
</Application.ApplicationLifetimeObjects>

显然，视图是在之前应用资源创建的！

在Silverlight 4中使用带有子窗口的MVVM Light View模型定位器

2 个答案: