WPF数据验证中的绑定失败

时间:2013-01-08 16:17:29

标签: c# wpf validation binding

我正在尝试从我的控件样式绑定到属性到控件中定义的属性。控件继承自TextBox,称为ChangeTextBoxWithRangeUnits。我正在尝试从我创建的ValidationRule类绑定它们。以下是我正在尝试验证文本的Setter

 <Setter Property="Text">
        <Setter.Value>
            <Binding RelativeSource="{RelativeSource Self}"
                     Path="Text"
                     NotifyOnValidationError="True">
                <Binding.ValidationRules>
                    <basic:DoubleValidationRule>
                        <basic:DoubleValidationRule.MinMaxDependencyObject>
                            <basic:MinMaxDependencyObject Minimum="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type local:ChangeTextBoxWithRangeUnits}}, Path=MinimumValue}"
                                                          Maximum="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type local:ChangeTextBoxWithRangeUnits}}, Path=MaximumValue}" />
                        </basic:DoubleValidationRule.MinMaxDependencyObject>
                    </basic:DoubleValidationRule>
                </Binding.ValidationRules>
            </Binding>
        </Setter.Value>
    </Setter>

我不明白为什么它说无法找到源绑定。这是错误:

  

System.Windows.Data错误:4:无法找到与引用'RelativeSource FindAncestor绑定的源,AncestorType ='Frasca.Simplicity.Controls.UnitControls.ChangeTextBoxWithRangeUnits',AncestorLevel ='1''。 BindingExpression:路径= MinimumValue;的DataItem = NULL; target元素是'MinMaxDependencyObject'(HashCode = 16320155); target属性为'Minimum'(类型为'Double')

编辑完成XAML

 <Style x:Key="ChangeTextBoxWithRangeUnits"
       TargetType="{x:Type local:ChangeTextBoxWithRangeUnits}"
       BasedOn="{StaticResource {x:Type TextBox}}">
    <Setter Property="Validation.ErrorTemplate"
            Value="{x:Null}" />
    <Setter Property="Height"
            Value="64" />
    <Setter Property="FontSize"
            Value="22" />
    <Setter Property="Margin"
            Value="5" />
    <Setter Property="Background"
            Value="LightGray" />
    <Setter Property="BorderThickness"
            Value="0" />
    <Setter Property="KeyboardNavigation.TabNavigation"
            Value="None" />
    <Setter Property="AllowDrop"
            Value="true" />
    <Setter Property="ScrollViewer.PanningMode"
            Value="VerticalFirst" />
    <Setter Property="Stylus.IsFlicksEnabled"
            Value="False" />
    <Setter Property="Text">
        <Setter.Value>
            <Binding RelativeSource="{RelativeSource Self}"
                     Path="Text"
                     NotifyOnValidationError="True">
                <Binding.ValidationRules>
                    <basic:DoubleValidationRule>
                        <basic:DoubleValidationRule.MinMaxDependencyObject>
                            <basic:MinMaxDependencyObject Minimum="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type local:ChangeTextBoxWithRangeUnits}}, Path=MinimumValue}"
                                                          Maximum="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type local:ChangeTextBoxWithRangeUnits}}, Path=MaximumValue}" />
                        </basic:DoubleValidationRule.MinMaxDependencyObject>
                    </basic:DoubleValidationRule>
                </Binding.ValidationRules>
            </Binding>
        </Setter.Value>
    </Setter>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type local:ChangeTextBoxWithUnits}">
                <Grid>
                    <Border Name="bg"
                            Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}"
                            Width="{TemplateBinding Width}"
                            CornerRadius="15"
                            SnapsToDevicePixels="true">
                        <Grid>
                            <Grid.RowDefinitions>
                                <RowDefinition Height="3*" />
                                <RowDefinition Height="Auto" />
                                <RowDefinition Height="2*" />
                            </Grid.RowDefinitions>

                            <StackPanel Orientation="Horizontal"
                                        Grid.Row="0"
                                        Name="mValueStackPanel"
                                        VerticalAlignment="Bottom"
                                        HorizontalAlignment="Center">
                                <ScrollViewer x:Name="PART_ContentHost"
                                              SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />
                                <TextBox Name="PART_UnitTextBlock"
                                         Style="{DynamicResource InlineTextBox}"
                                         Text="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type local:ChangeTextBoxWithUnits}}, Path=Units}"
                                         FontSize="14"
                                         Margin="3,0,0,0"
                                         Foreground="{TemplateBinding Foreground}" />
                            </StackPanel>

                            <StackPanel Orientation="Horizontal"
                                        Grid.Row="2"
                                        HorizontalAlignment="Center"
                                        VerticalAlignment="Top">
                                <TextBlock Text="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type local:ChangeTextBoxWithUnits}}, Path=Label}"
                                           FontSize="14"
                                           Foreground="{TemplateBinding Foreground}" />
                            </StackPanel>

                            <TextBlock Text="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type local:ChangeTextBoxWithUnits}}, Path=DisabledText}"
                                       Foreground="{TemplateBinding Foreground}"
                                       Grid.Row="0"
                                       FontSize="14"
                                       HorizontalAlignment="Center"
                                       VerticalAlignment="Bottom"
                                       Visibility="Collapsed"
                                       x:Name="mDisabledTextBlock" />

                            <!-- Horizontal line -->
                            <Rectangle Height="1"
                                       Margin="10,0"
                                       Grid.Row="1"
                                       Opacity="0.15"
                                       SnapsToDevicePixels="True"
                                       Fill="{TemplateBinding Foreground}" />

                            <!-- Object which flashes when the textbox is selected -->
                            <Border Grid.RowSpan="3"
                                    Background="White"
                                    Name="FlashObject"
                                    CornerRadius="15"
                                    Opacity="0">
                                <Border.Effect>
                                    <BlurEffect Radius="20" />
                                </Border.Effect>
                            </Border>

                            <!-- Object which flashes when the textbox has a validation error-->
                            <Border Grid.RowSpan="3"
                                    Grid.ColumnSpan="2"
                                    Background="Red"
                                    Name="ErrorFlashObject"
                                    CornerRadius="15"
                                    Opacity="0">
                                <Border.Effect>
                                    <BlurEffect Radius="20" />
                                </Border.Effect>
                            </Border>
                        </Grid>
                    </Border>

                    <!-- Object which glows when the user makes a change to the text value. -->
                    <Border Width="{Binding ElementName=bg, Path=ActualWidth}"
                            Height="{Binding ElementName=bg, Path=ActualHeight}"
                            CornerRadius="15"
                            Background="#FFF066"
                            Name="ChangeGlowObject"
                            Panel.ZIndex="-1"
                            Visibility="Collapsed">
                        <Border.Effect>
                            <BlurEffect Radius="20" />
                        </Border.Effect>
                    </Border>
                </Grid>
                <ControlTemplate.Triggers>
                    <MultiTrigger>
                        <MultiTrigger.Conditions>
                            <Condition Property="HasChangedValue"
                                       Value="True" />
                            <Condition Property="IsEnabled"
                                       Value="True" />
                        </MultiTrigger.Conditions>
                        <Setter Property="Visibility"
                                TargetName="ChangeGlowObject"
                                Value="Visible" />
                    </MultiTrigger>
                    <Trigger Property="IsEnabled"
                             Value="False">
                        <Setter Property="Background"
                                Value="#686868" />
                    </Trigger>
                    <MultiTrigger>
                        <MultiTrigger.Conditions>
                            <Condition Property="IsEnabled"
                                       Value="False" />
                            <!--<Condition Property="ShowTextWhenDisabled"
                                       Value="False" />-->
                        </MultiTrigger.Conditions>
                        <Setter Property="Visibility"
                                TargetName="mDisabledTextBlock"
                                Value="Visible" />
                        <Setter Property="Visibility"
                                TargetName="mValueStackPanel"
                                Value="Collapsed" />
                    </MultiTrigger>

                    <!-- trigger to flash the object when the textbox has an error -->
                    <Trigger Property="Validation.HasError"
                             Value="True">
                        <Trigger.EnterActions>
                            <BeginStoryboard>
                                <Storyboard>
                                    <DoubleAnimation BeginTime="00:00:00"
                                                     Duration="00:00:00.2"
                                                     From="0"
                                                     To="1"
                                                     Storyboard.TargetName="ErrorFlashObject"
                                                     Storyboard.TargetProperty="Opacity">
                                        <DoubleAnimation.EasingFunction>
                                            <PowerEase Power="2"
                                                       EasingMode="EaseIn" />
                                        </DoubleAnimation.EasingFunction>
                                    </DoubleAnimation>
                                    <DoubleAnimation BeginTime="00:00:00.2"
                                                     Duration="00:00:00.5"
                                                     From="1"
                                                     To="0"
                                                     Storyboard.TargetName="ErrorFlashObject"
                                                     Storyboard.TargetProperty="Opacity">
                                        <DoubleAnimation.EasingFunction>
                                            <PowerEase Power="2"
                                                       EasingMode="EaseIn" />
                                        </DoubleAnimation.EasingFunction>
                                    </DoubleAnimation>
                                </Storyboard>
                            </BeginStoryboard>
                        </Trigger.EnterActions>
                    </Trigger>

                    <!-- trigger to flash the object when the textbox is selected -->
                    <EventTrigger RoutedEvent="FocusManager.GotFocus">
                        <BeginStoryboard>
                            <Storyboard>
                                <DoubleAnimation BeginTime="00:00:00"
                                                 Duration="00:00:00.2"
                                                 From="0"
                                                 To="1"
                                                 Storyboard.TargetName="FlashObject"
                                                 Storyboard.TargetProperty="Opacity">
                                    <DoubleAnimation.EasingFunction>
                                        <PowerEase Power="2"
                                                   EasingMode="EaseIn" />
                                    </DoubleAnimation.EasingFunction>
                                </DoubleAnimation>
                                <DoubleAnimation BeginTime="00:00:00.2"
                                                 Duration="00:00:00.5"
                                                 From="1"
                                                 To="0"
                                                 Storyboard.TargetName="FlashObject"
                                                 Storyboard.TargetProperty="Opacity">
                                    <DoubleAnimation.EasingFunction>
                                        <PowerEase Power="2"
                                                   EasingMode="EaseIn" />
                                    </DoubleAnimation.EasingFunction>
                                </DoubleAnimation>
                            </Storyboard>
                        </BeginStoryboard>
                    </EventTrigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

1 个答案:

答案 0 :(得分:1)

RelativeSource绑定不会向上移动XML,它们会向上走 Visual Tree 。这意味着只要您绑定的元素位于该树中,您就可以使用它。

在这种情况下,您的DoubleValidationRule 是一个UIElement,它在可视化树中,因此RelativeSouce绑定到此规则将失败。

不幸的是,如果不知道DoubleValidationRule.MinMaxDependencyObject的实现或目的,很难说你应该做什么。您可以通过更改验证规则的实现来解决此限制。

一种可行的方法是,您可以通过x:Name

引用树中的元素
Minimum="{Binding MinimumValue, ElementName=TheMinimumTarget}

但这可能意味着您无法使用Style执行此操作,因为每次使用都会(可能)绑定到表单上的其他元素。


看着你的编辑...... Wat?您是否将控件的文本绑定到控件的文本以附加验证规则?那是......我甚至没有。

我建议对控件进行子类化以添加验证逻辑(例如,覆盖Text依赖项属性的属性元数据),然后将模板应用于此新类型。