WPF用户控件显示配置错误

Question

我有一个简单的UserControl

<UserControl x:Class="UIWpf.UserControls.MultiSelectEnvironmentContextControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d"
             d:DesignHeight="500" d:DesignWidth="500">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="25*"/>
            <RowDefinition Height="30*"/>
            <RowDefinition Height="31*"/>
            <RowDefinition Height="29*"/>
            <RowDefinition Height="36*"/>
            <RowDefinition Height="149*"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="149*"/>
            <ColumnDefinition Width="151*"/>
        </Grid.ColumnDefinitions>

        <ComboBox Grid.Column="0" Grid.Row="0" x:Name="ComboBoxVersions" SelectedIndex="0">
            <ComboBox.ItemTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding}" />
                </DataTemplate>
            </ComboBox.ItemTemplate>
        </ComboBox>

        <StackPanel Orientation="Horizontal" Grid.Column="1" Grid.Row="0">
            <TextBlock >Tests to be run for:</TextBlock>
            <ComboBox  Name="ComboBoxFileTypeSelector" DisplayMemberPath="Key" SelectedValuePath="Value" SelectedIndex="0">
            </ComboBox>
        </StackPanel>

    </Grid>
</UserControl>

现在，我在MainWindow.xaml中使用此UserControl

<Window x:Class="UIWpf.MainWindow"
        xmlns:u="clr-namespace:UIWpf.UserControls"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition></ColumnDefinition>
            <ColumnDefinition></ColumnDefinition>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
      <RowDefinition>
      </RowDefinition>
    </Grid.RowDefinitions>
        <u:MultiSelectEnvironmentContextControl x:Name="MultiSelectEnvironmentContextControl"></u:MultiSelectEnvironmentContextControl>
         </Grid>
</Window>

UserControl使用数据绑定，数据来自配置文件中配置的源。

我在app.config中有配置设置，当我运行应用程序时，MainForm可以正常使用填充了数据的UserControl。 但是在编译时我仍然看到一个错误说，配置文件中缺少设置。