WPF验证问题（IDataErrorInfo）并动态加载用户控件

Question

我有一个用户控件并且我使用（IDataErrorInfo）进行验证问题是当我加载用户控件时动态验证第一次没有出现但是当我在设计时加载它它的工作原理是什么问题？ 这是用户控件

 <UserControl x:Class="WeaponLibrary.WeaponUserControl"
         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"
         xmlns:local="clr-namespace:WeaponLibrary"
         xmlns:controls="http://metro.mahapps.com/winfx/xaml/controls"
         xmlns:ad="clr-namespace:DataAccessClassLibrary.ValidationRules;assembly=DataAccessClassLibrary"
         mc:Ignorable="d"
         d:DataContext="{d:DesignInstance local:WeaponUserControlViewModel}"
        Height="700" Width="730" FlowDirection="RightToLeft" Loaded="UserControl_Loaded" >
<AdornerDecorator>
    <Expander  IsExpanded="True" >
        <DockPanel>
            <WrapPanel DockPanel.Dock="Top"   DataContext="{Binding Path=SelectedWeapon}">
                <StackPanel Width="315" Margin="20,0,10,0">

                    <ComboBox x:Name="CmbWeaponType" IsReadOnly="True" IsEditable="True"
                          ItemsSource="{Binding RelativeSource={RelativeSource FindAncestor, 
                          AncestorType={x:Type UserControl}}, Path=DataContext.WeaponTypeList,ValidatesOnNotifyDataErrors =True,ValidatesOnDataErrors=True,
                    NotifyOnValidationError=True,UpdateSourceTrigger=PropertyChanged}" DisplayMemberPath="weaponTypeName" SelectedValuePath="ID" >
                        <ComboBox.SelectedValue>
                            <Binding Path="weaponTypeID" Mode="TwoWay" 
                                 UpdateSourceTrigger="PropertyChanged" ValidatesOnNotifyDataErrors="True" NotifyOnValidationError="True">
                            </Binding>
                        </ComboBox.SelectedValue>
                    </ComboBox>
                </StackPanel>
                <StackPanel Width="315" Margin="20,0,10,0" >

                    <TextBox x:Name="TxtWeaponNumber" Width="315" Text="{Binding weaponNumber,UpdateSourceTrigger=PropertyChanged, NotifyOnValidationError=True ,ValidatesOnNotifyDataErrors=True,ValidatesOnDataErrors=True,NotifyOnSourceUpdated=True,NotifyOnTargetUpdated=True,ValidatesOnExceptions=True}"  >
                        <!--<TextBox.Text>
                            <Binding Path="weaponNumber">
                                <Binding.ValidationRules >
                                    <ad:RequiredRule ValidatesOnTargetUpdated="True"  />
                                </Binding.ValidationRules>
                            </Binding>
                        </TextBox.Text>-->
                    </TextBox>
                </StackPanel>
                <StackPanel Width="315" Margin="20,0,10,0">

                    <TextBox x:Name="TxtOwnership" Width="315"
                         controls:TextBoxHelper.IsWaitingForData="True"
                         Text="{Binding Path=ownership}" />
                </StackPanel>
                <StackPanel Width="315" Margin="20,0,10,0">

                    <TextBox x:Name="TxtMagazineNumber" Width="315"
                         controls:TextBoxHelper.IsWaitingForData="True"
                         Text="{Binding Path=magazineNumber}" />
                </StackPanel>
                <StackPanel>

                    <TextBox x:Name="TxtNotes" Margin="20,0,10,0" Width="660" Height="100"
                         controls:TextBoxHelper.IsWaitingForData="True" Text="{Binding Path=note}" />
                </StackPanel>
                <StackPanel Width="660" Margin="10,10,10,0">
                    <TextBlock Text="{Binding AllErrors}"  Foreground="Red" >

                    </TextBlock>
                </StackPanel >


            </WrapPanel>
            <DataGrid x:Name="DgvWeapons" Margin="0,10,0,10" VerticalContentAlignment="Center"  ItemsSource="{Binding WeaponsList, Mode=OneWay,ValidatesOnNotifyDataErrors=False,NotifyOnValidationError=False}"  
                  HorizontalContentAlignment="Center" IsReadOnly="True"  AlternatingRowBackground="{DynamicResource AccentColorBrush4}" SelectionMode="Single" 
                  CanUserDeleteRows="False" CanUserAddRows="False" AutoGenerateColumns="False" Width="657"  SelectedItem="{Binding SelectedWeapon,ValidatesOnNotifyDataErrors=False,NotifyOnValidationError=False}" MouseLeftButtonDown="DgvWeapons_MouseLeftButtonDown">
                <DataGrid.Columns>
                    <DataGridTextColumn Width="100" Binding="{Binding Path=WeaponTypeName}" />
                    <DataGridTextColumn  Width="100" Binding="{Binding Path=weaponNumber}"/>
                    <DataGridTextColumn  Width="100" Binding="{Binding Path=ownership}"/>
                    <DataGridTextColumn  Width="100" Binding="{Binding Path=magazineNumber}"/>
                    <DataGridTextColumn  Width="100" Binding="{Binding Path=note}"/>
                </DataGrid.Columns>
            </DataGrid>
        </DockPanel>
    </Expander>
</AdornerDecorator>
</UserControl>

这是代码：

var tabItem = new TabItem { Header = item.FormName };
var adornerDecorator = new AdornerDecorator();
var stackPanel = new StackPanel();
stackPanel.Children.Add(item.MainForm);
adornerDecorator.Child = stackPanel;
tabItem.Content = adornerDecorator;
tabItem.SetValue(ControlsHelper.HeaderFontSizeProperty, 18.0);
MainTabControl.Items.Add(tabItem);

这是实施代码

    public string Error
    {
        get {return string.Empty; }
    }

    public string this[string columnName]
    {
        get
        {
            if (columnName == "weaponNumber")
            {
                bool valid = !string.IsNullOrEmpty(weaponNumber);

                if (!valid)
                {
                    var propertyErrors = new List<string>();
                    propertyErrors.Add("error message");
                    SetErrors("weaponNumber", propertyErrors);
                    return "error message";
                }
                else
                {
                    ClearErrors("weaponNumber");
                }
                OnPropertyChanged("AllErrors");
            }

            if (columnName == "weaponTypeID")
            {
                bool valid = weaponTypeID != null && weaponTypeID != new Guid();

                if (!valid)
                {
                    var propertyErrors = new List<string>();
                    propertyErrors.Add("error message");
                    SetErrors("weaponTypeID", propertyErrors);
                }
                else
                {
                    ClearErrors("weaponTypeID");
                }
                OnPropertyChanged("AllErrors");
                return "error message";
            }

            return null;
        }
    }