使用IdataInfoError文本框后不允许浮点值

Question

Xaml代码：

   <StackPanel Grid.Row="1" Grid.Column="2" Orientation="Horizontal" HorizontalAlignment="Left" VerticalAlignment="Center" >
                <TextBox Style="{StaticResource EditValueStyle}" HorizontalAlignment="Left"   Text="{Binding TemperatureManualInput,UpdateSourceTrigger=PropertyChanged,ValidatesOnDataErrors=true, NotifyOnValidationError=true }" Height="Auto" VerticalAlignment="Center" HorizontalContentAlignment="Right" VerticalContentAlignment="Center" />
                <TextBlock Text="{Binding Units}"    Style="{StaticResource _unit_rangeStyle}" HorizontalAlignment="Left"  VerticalAlignment="Center"  />
                <TextBlock Text="{Binding ManualTemperatureInputRange}"    Style="{StaticResource _unit_rangeStyle}" HorizontalAlignment="Left"  VerticalAlignment="Center"  />
            </StackPanel>

Style.xaml

<Style x:Key="EditValueStyle" TargetType="TextBox">
        <Setter Property="Control.HorizontalAlignment" Value="Left" />
        <Setter Property="Control.VerticalAlignment" Value="Center" />
        <Setter Property="Control.Height" Value="Auto" />
        <Setter Property="Control.HorizontalContentAlignment" Value="Right" />
        <Setter Property="Control.VerticalContentAlignment" Value="Center" />
        <Setter Property="Control.Foreground" Value="#333" />
        <Setter Property="Control.Width" Value="60" />
        <Setter Property="Control.FontSize" Value="14" />
        <Setter Property="MaxLength" Value="8"></Setter>
        <Setter Property="Control.Margin" Value="0,0,15,0" />
        <Setter Property="Control.FontFamily" Value="Segoe UI Symbol" />
            <Setter Property="Validation.ErrorTemplate">

                <Setter.Value>
                    <ControlTemplate>
                        <DockPanel LastChildFill="true">
                            <Border Background="Red" DockPanel.Dock="right" Margin="3,0,0,0" Width="15" Height="15" CornerRadius="10"   ToolTip="{Binding ElementName=customAdorner, Path=AdornedElement.(Validation.Errors)[0].ErrorContent}">
                                <TextBlock Text="!" VerticalAlignment="center" HorizontalAlignment="center" FontWeight="Bold" Foreground="white">
                                </TextBlock>
                            </Border>
                            <AdornedElementPlaceholder Name="customAdorner" VerticalAlignment="Center" >
                                <Border BorderBrush="red" BorderThickness="1" />
                            </AdornedElementPlaceholder>
                        </DockPanel>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>

    </Style>

的.cs

public float TemperatureManualInput
        {
            get { return _temperatureManualInput; }
            set
            {
                _temperatureManualInput = value;
                OnPropertyChanged(nameof(TemperatureManualInput));
                EnableDisableSave?.Invoke();
              // DisableSaveButton?.Invoke(false);
            }
        }
 public string Error
        {
            get { return String.Empty; }
        }
        public  string this[string columnName]
        {
            get
            {
                String errorMessage = String.Empty;
                switch (columnName)
                {
                    case "TemperatureManualInput":
                        if (TemperatureManualInput < ManualTemperatureInputMin || TemperatureManualInput > ManualTemperatureInputMax)//ExternalTemperatureInputMax< TwentyMATemperatureValue || ExternalTemperatureInputMin> TwentyMATemperatureValue)
                        {
                            errorMessage = "Out of Range";
                           // SaveButtonStatusChanged();
                            IsEnabled = false;

                            //DisableSaveButton(false);
                        }

                        break;


                }
                if (errorMessage != string.Empty && !(Errors.ContainsKey(columnName)))Errors.Add(columnName, errorMessage);

                return errorMessage;
            }
        }

这是我的简短代码，我有一个允许浮点的文本框，但在添加验证后它不允许浮动。请帮我解决。谢谢提前。