BindingGroup.ValidationRules 属性

定义

获取 ValidationRule 对象的集合,这些对象验证 BindingGroup 中的源对象。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)

属性值

Collection<ValidationRule>

ValidationRule 对象的集合,这些对象验证 BindingGroup 中的源对象。A collection of ValidationRule objects that validate the source objects in the BindingGroup.

示例

下面的示例将自定义 ValidationRule 添加 ValidateDateAndPriceBindingGroupThe 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>

下面的示例展示了 ValidateDateAndPrice 类。The following example shows the ValidateDateAndPrice class. Validate方法使用 BindingGroup 来获取用户在窗体中输入的值,并检查项是否超过100美元,此值至少可用于七天。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

注解

ValidationRule 添加到时,将 BindingGroup BindingGroup 传入作为方法的第一个参数 ValidateWhen a ValidationRule is added to a BindingGroup, the BindingGroup is passed in as the first parameter of the Validate method. 您可以通过使用或方法获取对象的建议值 TryGetValue GetValue(Object, String)You can get the proposed values of the object by using the TryGetValue or GetValue(Object, String) method. 可以从属性获取作为绑定源的对象 ItemsYou can get the objects that are the sources of the bindings from the Items property.

适用于