C# 如果验证失败，则创建VisualState（UWP）

我在Usercontrol中有Textbox，如果对Textbox的验证失败，我想创建一个visualstate。我的代码如下所示

<Grid>
    <TextBox Style="{StaticResource ExtendeTextBoxStyle}" PlaceholderText="I'am Active"   HasError="{Binding IsInvalid, UpdateSourceTrigger=PropertyChanged}"  Height="80" Width="300"  x:Name="txtActive"  Text="{Binding TextValue, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" ></TextBox>
</Grid>

---

我在这里所做的，以及我如何确保当文本框验证失败时，我的新

VisualState

被激活

textbox

没有

HasError

属性，因此我们无法直接设置它，我们需要创建

HasError

附加属性并检测textbox

TextChanged

事件，然后检查文本是否有效

根据您的要求，我们建议使用方法。并使用

XamlBehaviors

调用

VisualState

命令

比如说

<StackPanel>
    <TextBox
        Name="PhoneNumberValidator"
        extensions:TextBoxRegex.Regex="^\s*\+?\s*([0-9][\s-]*){9,}$"
        Background="Red"
        Header="Text box with Regex extension for phone number, validation occurs on TextChanged"
        >
        <Interactivity:Interaction.Behaviors>
            <Interactions:DataTriggerBehavior Binding="{Binding (extensions:TextBoxRegex.IsValid), ElementName=PhoneNumberValidator}" Value="True">
                <Interactions:GoToStateAction StateName="BlueState" />
            </Interactions:DataTriggerBehavior>
            <Interactions:DataTriggerBehavior Binding="{Binding (extensions:TextBoxRegex.IsValid), ElementName=PhoneNumberValidator}" Value="False">
                <Interactions:GoToStateAction StateName="RedState" />
            </Interactions:DataTriggerBehavior>
        </Interactivity:Interaction.Behaviors>
    </TextBox>

    <VisualStateManager.VisualStateGroups>
        <VisualStateGroup x:Name="AdaptiveVisualStateGroup">
            <VisualState x:Name="BlueState">

                <VisualState.Setters>
                    <Setter Target="PhoneNumberValidator.Background" Value="Blue" />
                </VisualState.Setters>
            </VisualState>
            <VisualState x:Name="RedState">

                <VisualState.Setters>
                    <Setter Target="PhoneNumberValidator.Background" Value="Red" />
                </VisualState.Setters>
            </VisualState>

        </VisualStateGroup>
    </VisualStateManager.VisualStateGroups>
</StackPanel>

Unknown member 'HasError' on element 'TextBox'  

<StackPanel>
    <TextBox
        Name="PhoneNumberValidator"
        extensions:TextBoxRegex.Regex="^\s*\+?\s*([0-9][\s-]*){9,}$"
        Background="Red"
        Header="Text box with Regex extension for phone number, validation occurs on TextChanged"
        >
        <Interactivity:Interaction.Behaviors>
            <Interactions:DataTriggerBehavior Binding="{Binding (extensions:TextBoxRegex.IsValid), ElementName=PhoneNumberValidator}" Value="True">
                <Interactions:GoToStateAction StateName="BlueState" />
            </Interactions:DataTriggerBehavior>
            <Interactions:DataTriggerBehavior Binding="{Binding (extensions:TextBoxRegex.IsValid), ElementName=PhoneNumberValidator}" Value="False">
                <Interactions:GoToStateAction StateName="RedState" />
            </Interactions:DataTriggerBehavior>
        </Interactivity:Interaction.Behaviors>
    </TextBox>

    <VisualStateManager.VisualStateGroups>
        <VisualStateGroup x:Name="AdaptiveVisualStateGroup">
            <VisualState x:Name="BlueState">

                <VisualState.Setters>
                    <Setter Target="PhoneNumberValidator.Background" Value="Blue" />
                </VisualState.Setters>
            </VisualState>
            <VisualState x:Name="RedState">

                <VisualState.Setters>
                    <Setter Target="PhoneNumberValidator.Background" Value="Red" />
                </VisualState.Setters>
            </VisualState>

        </VisualStateGroup>
    </VisualStateManager.VisualStateGroups>
</StackPanel>