BindingGroup.ValidationRules Proprietà

Definizione

Spazio dei nomi:

System.Windows.Data

Assembly:

PresentationFramework.dll

Ottiene un insieme di oggetti ValidationRule per la convalida degli oggetti origine in un insieme di tipo BindingGroup.

public:
 property System::Collections::ObjectModel::Collection<System::Windows::Controls::ValidationRule ^> ^ ValidationRules { System::Collections::ObjectModel::Collection<System::Windows::Controls::ValidationRule ^> ^ get(); };

public System.Collections.ObjectModel.Collection<System.Windows.Controls.ValidationRule> ValidationRules { get; }

member this.ValidationRules : System.Collections.ObjectModel.Collection<System.Windows.Controls.ValidationRule>

Public ReadOnly Property ValidationRules As Collection(Of ValidationRule)

Valore della proprietà

Collection<ValidationRule>

Un insieme di oggetti ValidationRule per la convalida degli oggetti origine in un insieme di tipo BindingGroup.

Esempio

Nell'esempio seguente l'oggetto personalizzato ValidationRule, ValidateDateAndPrice, viene aggiunto all'oggetto BindingGroup.

<StackPanel.BindingGroup>
  <BindingGroup NotifyOnValidationError="True">
    <BindingGroup.ValidationRules>
      <src:ValidateDateAndPrice ValidationStep="ConvertedProposedValue" />
    </BindingGroup.ValidationRules>
  </BindingGroup>
</StackPanel.BindingGroup>

L'esempio seguente illustra la classe ValidateDateAndPrice. Il Validate metodo usa per BindingGroup ottenere i valori immessi dall'utente nel modulo e controlla che, se un elemento è superiore a 100 dollari, sarà disponibile per almeno sette giorni.

public class ValidateDateAndPrice : ValidationRule
{
    // Ensure that an item over $100 is available for at least 7 days.
    public override ValidationResult Validate(object value, CultureInfo cultureInfo)
    {
        BindingGroup bg = value as BindingGroup;

        // Get the source object.
        PurchaseItem item = bg.Items[0] as PurchaseItem;
        
        object doubleValue;
        object dateTimeValue;

        // Get the proposed values for Price and OfferExpires.
        bool priceResult = bg.TryGetValue(item, "Price", out doubleValue);
        bool dateResult = bg.TryGetValue(item, "OfferExpires", out dateTimeValue);

        if (!priceResult || !dateResult)
        {
            return new ValidationResult(false, "Properties not found");
        }

        double price = (double)doubleValue;
        DateTime offerExpires = (DateTime)dateTimeValue;

        // Check that an item over $100 is available for at least 7 days.
        if (price > 100)
        {
            if (offerExpires < DateTime.Today + new TimeSpan(7, 0, 0, 0))
            {
                return new ValidationResult(false, "Items over $100 must be available for at least 7 days.");
            }
        }

        return ValidationResult.ValidResult;
    }
}

Public Class ValidateDateAndPrice
    Inherits ValidationRule
    ' Ensure that an item over $100 is available for at least 7 days.
    Public Overrides Function Validate(ByVal value As Object, ByVal cultureInfo As CultureInfo) As ValidationResult
        Dim bg As BindingGroup = TryCast(value, BindingGroup)

        ' Get the source object.
        Dim item As PurchaseItem = TryCast(bg.Items(0), PurchaseItem)

        Dim doubleValue As Object = Nothing
        Dim dateTimeValue As Object = Nothing

        ' Get the proposed values for Price and OfferExpires.
        Dim priceResult As Boolean = bg.TryGetValue(item, "Price", doubleValue)
        Dim dateResult As Boolean = bg.TryGetValue(item, "OfferExpires", dateTimeValue)

        If (Not priceResult) OrElse (Not dateResult) Then
            Return New ValidationResult(False, "Properties not found")
        End If

        Dim price As Double = CDbl(doubleValue)
        Dim offerExpires As Date = CDate(dateTimeValue)

        ' Check that an item over $100 is available for at least 7 days.
        If price > 100 Then
            If offerExpires < Date.Today + New TimeSpan(7, 0, 0, 0) Then
                Return New ValidationResult(False, "Items over $100 must be available for at least 7 days.")
            End If
        End If

        Return ValidationResult.ValidResult

    End Function
End Class

Commenti

ValidationRule Quando un oggetto viene aggiunto a un BindingGroupoggetto , viene BindingGroup passato come primo parametro del Validate metodo . È possibile ottenere i valori proposti dell'oggetto usando il TryGetValue metodo o GetValue(Object, String) . È possibile ottenere gli oggetti che rappresentano le origini delle associazioni dalla Items proprietà .