BindingGroup.ValidationRules Property

Updated: July 2008

Gets a collection of ValidationRule objects that validate the source objects in the BindingGroup.

Namespace:  System.Windows.Data
Assembly:  PresentationFramework (in PresentationFramework.dll)

public Collection<ValidationRule> ValidationRules { get; }
You cannot set this property in XAML.

Property Value

Type: System.Collections.ObjectModel.Collection<ValidationRule>
A collection of ValidationRule objects that validate the source objects in the BindingGroup.

When a ValidationRule is added to a BindingGroup, the BindingGroup is passed in as the first parameter of the Validate method. You can get the proposed values of the object by using the TryGetValue or GetValue(Object, String) method. You can get the objects that are the sources of the bindings from the Items property.

The following example adds the custom ValidationRule, ValidateDateAndPrice, to the BindingGroup. For the entire example, see Validate the Data of an Object Sample.

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

The following example shows the ValidateDateAndPrice class. 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;

    }
}

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5 SP1, 3.0 SP2

Date

History

Reason

July 2008

Added topic for new class.

SP1 feature change.

Was this page helpful?
(1500 characters remaining)
Thank you for your feedback

Community Additions

ADD
Show:
© 2015 Microsoft