[RelayCommand]
private void LostFocus()
{
GrowlTool.ShowError("123");
}
<TextBox
MinWidth="100"
hc:BorderElement.CornerRadius="0"
IsReadOnly="{Binding ElementName=CalModeComboBox, Path=SelectedIndex, Converter={StaticResource CalModeToBoolConverter}}"
Style="{StaticResource TextBoxBaseBaseStyle}"
Text="{Binding Curve.CrtFactor[0], StringFormat=0.###}"
TextAlignment="Center">
<hc:Interaction.Triggers>
<hc:EventTrigger EventName="LostFocus">
<hc:InvokeCommandAction Command="{Binding LostFocusCommand}" />
</hc:EventTrigger>
</hc:Interaction.Triggers>
</TextBox>
