When is ValidationSummary loaded? - silverlight

Question

I'm trying to realize when the ValidationSummary really loads and how can I force it to be loaded.
I've suscribed to loaded event to force a page validation and this is only triggered when I cause any "new" validation or open a ComboBox or something like this.
Any idea?? Thanks in advance.
Here goes my view:
<Grid Margin="0,3">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="120"></ColumnDefinition>
<ColumnDefinition Width="60" />
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="120"/>
<ColumnDefinition Width="60"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<sdk:Label Grid.Column="0" Target="{Binding ElementName=txtImporteTotal}" Content="Total Acto" VerticalAlignment="Center" HorizontalAlignment="Right" Margin="5,0"></sdk:Label>
<TextBox Grid.Column="1" Name="txtImporteTotal" Margin="5,0" VerticalAlignment="Center" HorizontalAlignment="Stretch" Text="{Binding ActoMedico.importe_total, Mode=TwoWay, ValidatesOnExceptions=True, ValidatesOnDataErrors=True, NotifyOnValidationError=True}"></TextBox>
<sdk:DescriptionViewer Target="{Binding ElementName=txtImporteTotal}" Grid.Column="2"></sdk:DescriptionViewer>
<sdk:Label Grid.Column="3" Target="{Binding ElementName=txtImporteMedico}" Content="Total Médico" VerticalAlignment="Center" HorizontalAlignment="Right" Margin="5,0"></sdk:Label>
<TextBox Grid.Column="4" Name="txtImporteMedico" Margin="5,0" VerticalAlignment="Center" HorizontalAlignment="Stretch" Text="{Binding ActoMedico.importe_medico, Mode=TwoWay, ValidatesOnExceptions=True, ValidatesOnDataErrors=True, NotifyOnValidationError=True}"></TextBox>
<sdk:DescriptionViewer Target="{Binding ElementName=txtImporteMedico}" Grid.Column="5"></sdk:DescriptionViewer>
This is its code behind, where I'm forcing the validation:
public ActoMedico()
{
InitializeComponent();
this.validationSummary.Loaded += new RoutedEventHandler(validationSummary_Loaded);
}
void validationSummary_Loaded(object sender, RoutedEventArgs e)
{
this.forzarValidacion();
}
private void forzarValidacion()
{
this.txtImporteMedico.GetBindingExpression(TextBox.TextProperty).UpdateSource();
this.txtImporteTotal.GetBindingExpression(TextBox.TextProperty).UpdateSource();
}
And finally, this is the model:
#region importe_medico
public const string importe_medicoPropertyName = "importe_medico";
private double? _importe_medico;
[Display(Description = "Importe")]
[Required(ErrorMessage = "Debe indicar el importe")]
public double? importe_medico
{
get
{
return _importe_medico;
}
set
{
Validator.ValidateProperty(value, new ValidationContext(this, null, null) { MemberName = importe_medicoPropertyName });
_importe_medico = value;
RaisePropertyChanged(importe_medicoPropertyName);
}
}
#endregion
#region importe_total
public const string importe_totalPropertyName = "importe_total";
private double? _importe_total;
[Display(Description = "Importe total")]
[Required(ErrorMessage = "Debe indicar el importe total")]
public double? importe_total
{
get
{
return _importe_total;
}
set
{
Validator.ValidateProperty(value, new ValidationContext(this, null, null) { MemberName = importe_totalPropertyName });
_importe_total = value;
RaisePropertyChanged(importe_totalPropertyName);
}
}
#endregion

Answer 1

As far as I see, you use the binding like {Binding ActoMedico.importe_total} in your text boxes. It means that the object bound to the UserControl must contain the property ActoMedico and the value of this property must contain the inner property importe_total.
I've added the following code to the code behind:
public class MainViewModel
{
public MainViewModel()
{
this.ActoMedico = new ItemViewModel();
}
public ItemViewModel ActoMedico { get; set; }
}
//...
public ActoMedico()
{
InitializeComponent();
this.DataContext = new MainViewModel(); //should be set in order to make bindings work
this.validationSummary.Loaded += new RoutedEventHandler(validationSummary_Loaded);
}
In the code above the ItemViewModel class is the class which contains those two properties from you last block of code. This class has a different name in your application, but I don't know it so I've named it in my way.
So now the ValidationSummary control will be displayed but with messages like Input string had an incorrect format. It is because the TextBox control expects the string data type whereas your view model has the double? data type. You can write a converter as a workaround to this issue:
public class DoubleToStringConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return value;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
var str = (string)value;
double d;
if (!double.TryParse(str, out d))
return null;
return d;
}
}
Usage:
<UserControl.Resources>
<local:DoubleToStringConverter x:Key="DoubleToStringConverter" />
</UserControl.Resources>
<!-- ... -->
<TextBox Text="{Binding ActoMedico.importe_total, Mode=TwoWay, Converter={StaticResource DoubleToStringConverter} ...
Anyway data annotations aren't easy to work with, so I reccomend to use the MVVM pattern and the INotifyDataErrorInfo interface. I've implemented the example of such validation here in my post, you can download source code and look how it is implemented.

Answer 2

Finally I get this by forcing a combobox to drop-down, force all the form validations and then undo the drop-down.
So I get the ValidationSummary from the beginning (I want every error from the start to be shown and disable the "save" button for the user.
Thanks so much for your help #vorrtex.