问题在于:

1. I have a simple form (textboxes, etc).
   • The bindings are all within a BindingGroup.
   • Each binding has UpdateSourceTrigger=Explicit set.
   • Some bindings have validation rules attached that do not allow blank/null values (required field).
2. I bind a brand new, empty object to the form.
3. Without entering any data, the user clicks the save button triggering BindingGroup.UpdateSources().
4. UpdateSources succeeds, no validation errors are triggered.

我相信,这是因为 WPF 只有在用户积极改变UI中该字段的价值时, 才会触发每个约束性的验证规则, 而且由于我最初将一个空对象绑在窗体上, 没有任何变化。 这不是我想要的行为 - 我希望在调用“ 更新源代码” 时, 所有验证规则都得到评估 。

有没有人知道什么(希望干净的)方法 来得到我想要的行为?

以下是 C# 和 XAML 代码的一个( 简化的、 简化的) 示例 :

< 加固> 工具元元模板.xaml.cs

private void addModelButton_Click(object sender, RoutedEventArgs e)
{
    ToolModel model = new ToolModel();

    // bind the model details view to the new model
    this.createModelBinding = new Binding();
    this.createModelBinding.Source = model;
    this.modelFormGrid.SetBinding(Grid.DataContextProperty, this.createModelBinding);
}

private void saveModelButton_Click(object sender, RoutedEventArgs e)
{
    Binding modelDataContext = this.modelFormGrid.GetBindingExpression(Grid.DataContextProperty).ParentBinding;

    if (modelDataContext == this.modelDetailsBinding && this.modelListBox.SelectedItem != null)
    {
        // update existing tool model
        if (this.modelFormBindingGroup.UpdateSources())
        {
            // ...
        }
    }
    else if (modelDataContext == this.createModelBinding)
    {
        // create new tool model
        ToolModel modelToCreate = (ToolModel)this.createModelBinding.Source;

        if (this.modelFormBindingGroup.UpdateSources())
        {
            Context.ToolModel.AddObject(modelToCreate);
            Context.SaveChanges();

            // ...
        }
    }
}

< 坚固 > TOLTypeModelPanel.xaml

<GroupBox
    Grid.Row="3"
    Grid.Column="2"
    Margin="5"
    Header="{x:Static prop:Resources.HeaderModelDetails}">
    <Grid x:Name="modelFormGrid" DataContext="{Binding ElementName=modelListBox, Path=SelectedItem}">

        <Grid.BindingGroup>
            <BindingGroup x:Name="modelFormBindingGroup" />
        </Grid.BindingGroup>

        <Label Grid.Row="0" Grid.Column="0" Content="{x:Static prop:Resources.LabelModelName}" />
        <TextBox x:Name="modelNameTextBox"
            Grid.Row="0"
            Grid.Column="1">
            <TextBox.Text>
                <Binding Path="ModelName" UpdateSourceTrigger="Explicit">
                    <Binding.ValidationRules>
                        <vr:RequiredValidationRule />
                    </Binding.ValidationRules>
                </Binding>
            </TextBox.Text>
        </TextBox>

        <Label Grid.Row="3" Grid.Column="0" Content="{x:Static prop:Resources.LabelModelParameter}" />
        <TextBox x:Name="modelParameterTextBox"
            Grid.Row="3"
            Grid.Column="1"
            Text="{Binding Path=ModelParameter, UpdateSourceTrigger=Explicit}" />

        <Label Grid.Row="4" Grid.Column="0" Content="{x:Static prop:Resources.LabelFactoryAssemblyName}" />
        <TextBox x:Name="modelFactoryAssemblyTextBox"
            Grid.Row="4"
            Grid.Column="1">
            <TextBox.Text>
                <Binding Path="FactoryAssemblyName" UpdateSourceTrigger="Explicit">
                    <Binding.ValidationRules>
                        <vr:NamespaceValidationRule />
                    </Binding.ValidationRules>
                </Binding>
            </TextBox.Text>
        </TextBox>

        <Button x:Name="saveModelButton"
            Width="100"
            Margin="36,0,0,0"
            IsEnabled="False"
            Content="{x:Static prop:Resources.ButtonSaveText}"
            Click="saveModelButton_Click" />
    </Grid>
</GroupBox>