App.xaml中的错误试图在Windows Phone 8项目中使用MVVM Light

Question

当我通过NuGet添加MVVM Light包时,我会在安装期间添加引用App.xaml文件中的行的错误.这些错误仅出现在Windows Phone 8项目中.Windows Phone 7项目中完全相同的行不会引发任何错误.MVVM Light添加的行是:

<ResourceDictionary>
    <vm:ViewModelLocator x:Key="Locator" d:IsDataSource="True" />
     <ResourceDictionary.MergedDictionaries></ResourceDictionary.MergedDictionaries>
</ResourceDictionary>

这些行位于结束</Application.Resources>标记之前."错误列表"窗格中报告的错误是:

• 每个字典必须有一个关联的密钥
• 名称"ViewModelLocator"在命名空间"clr-namespace:sdkVoiceAlarmClockWP8CS.ViewModel"中不存在

这似乎有意义,因为<ResourceDictionary>标记没有键属性.但是,如果我试图将这一行移动到外面 块,我得到一组全新的错误.

就ViewModelLocator问题而言,我进行了双重检查,并将以下命名空间作为属性添加到<Application>标记中,并且未标记任何错误:

xmlns:vm="clr-namespace:sdkVoiceAlarmClockWP8CS.ViewModel" mc:Ignorable="d"

为什么这一组完全相同的行在Windows Phone 7项目中运行良好？如何修复我在Windows Phone 8项目中遇到的命名空间问题？

以防这是由于更复杂的问题,这里是整个App.xaml文件:

<?xml version="1.0" encoding="utf-8"?>
<!-- 
    Copyright (c) 2012 Microsoft Corporation.  All rights reserved.
    Use of this sample source code is subject to the terms of the Microsoft license 
    agreement under which you licensed this sample source code and is provided AS-IS.
    If you did not accept the terms of the license agreement, you are not authorized 
    to use this sample source code.  For the terms of the license, please see the 
    license agreement between you and Microsoft.

    To see all Code Samples for Windows Phone, visit http://go.microsoft.com/fwlink/?LinkID=219604
-->
<Application x:Class="AlarmClockWithVoice.App" 
             xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone" 
             xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone" 
             xmlns:toolkit="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls.Toolkit" 
             xmlns:telerikPrimitives="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls.Primitives" 
             xmlns:p1="http://schemas.microsoft.com/winfx/2006/xaml" 
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:vm="clr-namespace:sdkVoiceAlarmClockWP8CS.ViewModel" mc:Ignorable="d"
             >

    <!--Application Resources-->
    <Application.Resources>
        <Style x:Key="TransitionPageStyle" TargetType="phone:PhoneApplicationPage">
            <Setter Property="toolkit:TransitionService.NavigationInTransition">
                <Setter.Value>
                    <toolkit:NavigationInTransition>
                        <toolkit:NavigationInTransition.Backward>
                            <toolkit:TurnstileTransition Mode="BackwardIn" />
                        </toolkit:NavigationInTransition.Backward>
                        <toolkit:NavigationInTransition.Forward>
                            <toolkit:TurnstileTransition Mode="ForwardIn" />
                        </toolkit:NavigationInTransition.Forward>
                    </toolkit:NavigationInTransition>
                </Setter.Value>
            </Setter>
            <Setter Property="toolkit:TransitionService.NavigationOutTransition">
                <Setter.Value>
                    <toolkit:NavigationOutTransition>
                        <toolkit:NavigationOutTransition.Backward>
                            <toolkit:TurnstileTransition Mode="BackwardOut" />
                        </toolkit:NavigationOutTransition.Backward>
                        <toolkit:NavigationOutTransition.Forward>
                            <toolkit:TurnstileTransition Mode="ForwardOut" />
                        </toolkit:NavigationOutTransition.Forward>
                    </toolkit:NavigationOutTransition>
                </Setter.Value>
            </Setter>
        </Style>
        <ResourceDictionary>
            <vm:ViewModelLocator x:Key="Locator" d:IsDataSource="True" />
            <ResourceDictionary.MergedDictionaries></ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>

    <Application.ApplicationLifetimeObjects>
        <!--Required object that handles lifetime events for the application-->
        <shell:PhoneApplicationService Launching="Application_Launching" Closing="Application_Closing" Activated="Application_Activated" Deactivated="Application_Deactivated" />
    </Application.ApplicationLifetimeObjects>

</Application>

Answer 1

我以前也遇到过这个问题。要使其在 WP8 中工作，请替换以下内容：

<ResourceDictionary>
    <vm:ViewModelLocator x:Key="Locator" d:IsDataSource="True" />
    <ResourceDictionary.MergedDictionaries></ResourceDictionary.MergedDictionaries>
</ResourceDictionary>

仅此而已：

<vm:ViewModelLocator x:Key="Locator" d:IsDataSource="True" />

但我没有理会为什么它在 WP7 上有效但在 WP8 上不起作用