我在mvvm模式设计中工作。 过了一会儿，我可以随意使用devExpress dialogService。
我必须从我的mainWindowViewModel绑定两个数据：一个用于填充组合框和一个对象的集合，绑定到布局控件（此对话框用于插入新项目）。
在我的usercontrol的头部，在对话框中显示，我有：
DataContext="{dxmvvm:ViewModelSource vm:MainWindowViewModel}"
通过这种方式正确绑定集合：
虽然不起作用的绑定是：
<dxlc:LayoutControl Grid.Column="1" Orientation="Vertical" UseLayoutRounding="True" Margin="0,10,0,0"
DataContext="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=UserControl},
Path=DataContext.impiantoVuoto, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">
layoutControl只是绑定到一个空对象。当我编写新字段并单击＆＃34; ok＆＃34;时，由于绑定，它必须保存这些数据。但这不起作用，当我去mainViewModel时，空对象仍然是空的。为什么呢？
这是我的整个用户控件：
<UserControl x:Class="MyNS.View.Generic.nuovoImpianto"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:MyNS"
xmlns:vm="clr-namespace:MyNS.ViewModel"
xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
xmlns:View="clr-namespace:MyNS.View"
xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid"
xmlns:dxe="http://schemas.devexpress.com/winfx/2008/xaml/editors"
xmlns:dxprg="http://schemas.devexpress.com/winfx/2008/xaml/propertygrid"
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
xmlns:sys="clr-namespace:System;assembly=mscorlib"
xmlns:dxlc="http://schemas.devexpress.com/winfx/2008/xaml/layoutcontrol"
xmlns:dxmvvm="http://schemas.devexpress.com/winfx/2008/xaml/mvvm"
DataContext="{dxmvvm:ViewModelSource vm:MainWindowViewModel}"
>
<UserControl.Resources>
<vm:InverseBooleanConverter x:Key="InverseBooleanConverter" />
</UserControl.Resources>
<StackPanel Orientation="Horizontal" HorizontalAlignment="Center" VerticalAlignment="Center">
<dxlc:LayoutControl Grid.Column="1" Orientation="Vertical" UseLayoutRounding="True" Margin="0,10,0,0"
DataContext="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=UserControl},
Path=DataContext.impiantoVuoto, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">
<dxlc:LayoutGroup Header="Info generali" View="GroupBox" Orientation="Vertical" >
<dxlc:LayoutItem Label="Codice">
<dxe:TextEdit EditValue="{Binding CODICE}" />
</dxlc:LayoutItem>
<dxlc:LayoutItem Label="Nome">
<dxe:TextEdit EditValue="{Binding NOME}"/>
</dxlc:LayoutItem>
<dxlc:LayoutItem Label="Città">
<dxe:TextEdit EditValue="{Binding LOCALITA}"/>
</dxlc:LayoutItem>
<dxlc:LayoutItem Label="Indirizzo">
<dxe:TextEdit EditValue="{Binding INDIRIZZO}"/>
</dxlc:LayoutItem>
<dxlc:LayoutItem Label="CAP">
<dxe:TextEdit EditValue="{Binding CAP}"/>
</dxlc:LayoutItem>
<dxlc:LayoutItem Label="P. IVA">
<dxe:TextEdit EditValue="{Binding PIVA}"/>
</dxlc:LayoutItem>
<dxlc:LayoutItem Label="Telefono">
<dxe:TextEdit EditValue="{Binding TELEFONO}"/>
</dxlc:LayoutItem>
<dxlc:LayoutItem Label="Responsabile">
<dxe:TextEdit EditValue="{Binding RESPONSABILE}"/>
</dxlc:LayoutItem>
<dxlc:LayoutItem Label="E-mail">
<dxe:TextEdit EditValue="{Binding EMAILS}"/>
</dxlc:LayoutItem>
</dxlc:LayoutGroup>
<dxlc:LayoutGroup Header="Configurazione tecnica" View="GroupBox" Orientation="Vertical">
<dxlc:LayoutItem Label="Tipo sistema">
<dxe:ComboBoxEdit IsTextEditable="False" EditValue="{Binding IDTTS}"
ItemsSource="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=UserControl},Path=DataContext.tts}" />
</dxlc:LayoutItem>
<dxlc:LayoutItem Label="Locazione">
<StackPanel Margin="0" Orientation="Horizontal" VerticalAlignment="Center" HorizontalAlignment="Left">
<RadioButton Content="{DynamicResource Locale}" Margin="10,0,0,0" x:Name="rd_LOCALE" VerticalAlignment="Center"
GroupName="LocationL" Panel.ZIndex="9" TabIndex="10" />
<RadioButton Content="{DynamicResource Remoto}" Margin="10,0,6,0" x:Name="rd_REMOTO" VerticalAlignment="Center"
IsChecked="{Binding REMOTO}" GroupName="LocationR" Panel.ZIndex="10" TabIndex="11" Tag="PRISMA"/>
</StackPanel>
</dxlc:LayoutItem>
<dxlc:LayoutItem Label="Tipo di connessione">
<StackPanel Margin="0" Orientation="Horizontal" VerticalAlignment="Center">
<RadioButton x:Name="rd_TIPOCONN" Content="{DynamicResource Terminale}" Margin="10,0,0,0" Tag="PRISMA" VerticalAlignment="Center" GroupName="TipoConnT"
Panel.ZIndex="11" TabIndex="12" />
<RadioButton x:Name="rd_SLAVE" Content="Slave" Margin="10,0,6,0" Tag="PRISMA" VerticalAlignment="Center" GroupName="TipoConnS"
IsChecked="{Binding TIPOCONN}" Panel.ZIndex="12" TabIndex="13" />
</StackPanel>
</dxlc:LayoutItem>
</dxlc:LayoutGroup>
<dxlc:LayoutGroup Header="Centralina STK" View="GroupBox" Orientation="Vertical">
<dxlc:LayoutItem >
<StackPanel DockPanel.Dock="Top" Orientation="Horizontal" HorizontalAlignment="Center" Margin="0,6">
<RadioButton x:Name="rd_sermatic" Content="{DynamicResource SI}" Margin="10,0,0,0" Tag="PRISMA" VerticalAlignment="Center" Width="100"
HorizontalAlignment="Left" IsChecked="{Binding SERMATIC}" GroupName="stkS" Panel.ZIndex="13" TabIndex="14" />
<RadioButton x:Name="rd_sermaticNO" Content="{DynamicResource NO}" Margin="10,0,0,0" Tag="PRISMA" VerticalAlignment="Center" Width="100"
HorizontalAlignment="Left" GroupName="stkN"
Panel.ZIndex="14" TabIndex="15" />
</StackPanel>
</dxlc:LayoutItem>
<dxlc:LayoutItem >
<!--<dxe:ComboBoxEdit EditValue="{Binding SERMATICCOM}"/>-->
<UniformGrid Rows="1" Columns="2" DockPanel.Dock="Top" Margin="4,0,4,4" IsEnabled="{Binding IsChecked, ElementName=rd_sermatic}">
<TextBlock Margin="0" TextWrapping="Wrap" Text="{DynamicResource PortaCOM}" TextAlignment="Right" VerticalAlignment="Center" HorizontalAlignment="Right"/>
<ComboBox x:Name="cmb_SERMATICCOM" Height="23" Margin="10,2,0,0" Panel.ZIndex="15" TabIndex="16">
<ComboBoxItem Content="COM1" />
<ComboBoxItem Content="COM2" />
<ComboBoxItem Content="COM3" />
<ComboBoxItem Content="COM4" />
<ComboBoxItem Content="COM5" />
<ComboBoxItem Content="COM6" />
<ComboBoxItem Content="COM7" />
<ComboBoxItem Content="COM8" />
</ComboBox>
</UniformGrid>
</dxlc:LayoutItem>
</dxlc:LayoutGroup>
</dxlc:LayoutControl>
</StackPanel>
</UserControl>
我的错误在哪里？