BindingGroup.ValidationRules 屬性

定義

取得 ValidationRule 物件的集合,這些物件會驗證 BindingGroup 中的來源物件。Gets a collection of ValidationRule objects that validate the source objects in the 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)

屬性值

ValidationRule 物件的集合,這些物件會驗證 BindingGroup 中的來源物件。A collection of ValidationRule objects that validate the source objects in the BindingGroup.

範例

下列範例會將自訂ValidationRule ValidateDateAndPrice的加入至BindingGroupThe following example adds the custom ValidationRule, ValidateDateAndPrice, to the BindingGroup.

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

下列範例顯示 ValidateDateAndPrice 類別。The following example shows the ValidateDateAndPrice class. Validate方法會BindingGroup使用來取得使用者在表單中輸入的值,並檢查項目是否超過100美元,其將可供使用至少7天。The Validate method uses the BindingGroup to get the values the user entered into the form, and checks that if an item is over 100 dollars, it will be available for at least seven days.

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

備註

當加入至時BindingGroup ,會傳入做為方法的第一個參數。 Validate BindingGroup ValidationRuleWhen a ValidationRule is added to a BindingGroup, the BindingGroup is passed in as the first parameter of the Validate method. 您可以使用TryGetValueGetValue(Object, String)方法來取得物件的建議值。You can get the proposed values of the object by using the TryGetValue or GetValue(Object, String) method. 您可以從Items屬性取得屬於系結來源的物件。You can get the objects that are the sources of the bindings from the Items property.

適用於