如何使默認的DoubleUpDown驗證樣式？

當我進入文成DoubleUpDown控制，復位和控制以紅色突出顯示。它看起來像這樣：如何使默認的DoubleUpDown驗證樣式？

如何申請相同的風格爲負數？

我通過創建PositiveNumberToColorConverter做到這一點，並將其應用巫邊界：

public class PositiveNumberToColorConverter : IValueConverter 
{ 
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture) 
    { 
     if(value is int?) 
     { 
      var intValue = (int?)value; 
      if (intValue == null) 
       return Brushes.Transparent; 
      else if (intValue.HasValue&&intValue.Value>=0) 
       return Brushes.Transparent; 

      else if(intValue.HasValue==false) 
       return Brushes.Transparent; 
      return Brushes.Red; 
     }   
     return Brushes.Red; 
    } 

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) 
    { 
     throw new NotImplementedException(); 
    } 
} 


<Border 
            Grid.Column="0"                    
            BorderThickness="1" 
            Background="Transparent"           
            BorderBrush="{Binding ObjectViewModel.Value,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged,Converter={StaticResource positiveNumberConverter}}"                              
          IsEnabled="{Binding ObjectViewModel.IsEnabled,Mode=TwoWay,TargetNullValue=False,FallbackValue=False,UpdateSourceTrigger=PropertyChanged}" 
            > 
          <xcd:DoubleUpDown 
          HorizontalAlignment="Stretch" 
          Margin="5" 
          Grid.Column="0" 
          Minimum="0" 
          Height="{Binding ElementName=tbName,Path=Height}" 
          Width="Auto" 
          IsEnabled="{Binding ObjectViewModel.IsEnabled,Mode=TwoWay,TargetNullValue=False,FallbackValue=False,UpdateSourceTrigger=PropertyChanged}" 
          Text="{Binding ObjectViewModel.Value,Mode=TwoWay,UpdateSourceTrigger=LostFocus}" > 
           <xcd:DoubleUpDown.Resources> 
            <Style TargetType="Popup"> 
             <Setter Property="TextBlock.TextAlignment" Value="Left"/> 
            </Style> 
           </xcd:DoubleUpDown.Resources> 
          </xcd:DoubleUpDown> 
         </Border>

但是，它看起來像這樣：