用触发器管理必填字段

Question

我想设置必填字段背景为红色，其他为绿色。所以我尝试在下面实现。但我无法控制带触发器的ValueConstraint Nullable属性。你能帮忙吗？

<Window x:Class="TriggerGirilmesigerekenalanlar.Window1" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
     xmlns:y="http://infragistics.com/Editors" 
    Title="Window1" Height="300" Width="300"> 
    <Window.Resources> 
     <Style TargetType="{x:Type y:XamTextEditor}"> 
      <Style.Triggers> 
       <Trigger Property="ValueConstraint" Value="{x:Null}"> 
        <Trigger.Setters> 
         <Setter Property="Background" Value="green"></Setter> 
        </Trigger.Setters> 
       </Trigger> 
       <Trigger Property="y:ValueConstraint.Nullable" Value="false"> 
        <Trigger.Setters> 
         <Setter Property="Background" Value="red"></Setter> 
        </Trigger.Setters> 
       </Trigger> 
      </Style.Triggers> 
     </Style> 
    </Window.Resources> 
    <StackPanel> 
     <y:XamTextEditor> 
      <y:XamTextEditor.ValueConstraint> 
       <y:ValueConstraint Nullable="False" ></y:ValueConstraint> 
      </y:XamTextEditor.ValueConstraint> 
     </y:XamTextEditor> 
     <y:XamTextEditor></y:XamTextEditor> 
    </StackPanel> 
</Window> 

---

其实它给错误。

错误1无法解析样式属性'可空'。验证拥有的类型是Style的TargetType，还是使用Class.Property语法指定属性。线15的位置26 d：\ Deneme幻灯\ TriggerGirilmesigerekenalanlar \ Window1.xaml 15 26 TriggerGirilmesigerekenalanlar

Answer 1

试试这个：

<Style.Triggers> 
    <Trigger Property="ValueConstraint.Nullable" Value="{x:Null}"> 
     <Trigger.Setters> 
      <Setter Property="Background" Value="Green"></Setter> 
     </Trigger.Setters> 
    </Trigger> 
    <Trigger Property="ValueConstraint.Nullable" Value="false"> 
     <Trigger.Setters> 
      <Setter Property="Background" Value="Red"></Setter> 
     </Trigger.Setters> 
    </Trigger> 
</Style.Triggers> 

Answer 2

这就是答案。

<Style TargetType="{x:Type y:XamTextEditor}"> 
      <Style.Triggers> 
       <MultiDataTrigger> 
        <MultiDataTrigger.Conditions> 
         <Condition Binding="{Binding Path=ValueConstraint.Nullable, RelativeSource={RelativeSource Self}}" Value="false" /> 
         <Condition Binding="{Binding Path=IsReadOnly, RelativeSource={RelativeSource Self}}" Value="false" /> 
         <Condition Binding="{Binding Path=IsEnabled, RelativeSource={RelativeSource Self}}" Value="true" /> 
         <Condition Binding="{Binding Path=Visibility, RelativeSource={RelativeSource Self}}" Value="Visible" /> 
        </MultiDataTrigger.Conditions> 
        <Setter Property="Background" Value="red"></Setter> 
       </MultiDataTrigger> 
      </Style.Triggers> 
     </Style>