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ActivityValidator Class

Derivative of DependencyObjectValidator that is a base class for all activity validator components.

Namespace:  System.Workflow.ComponentModel.Compiler
Assembly:  System.Workflow.ComponentModel (in System.Workflow.ComponentModel.dll)

public class ActivityValidator : DependencyObjectValidator

The ActivityValidator type exposes the following members.

Public methodActivityValidatorInitializes a new instance of the ActivityValidator class.

Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Protected methodGetFullPropertyNameHelper method to extract the full property name. (Inherited from Validator.)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Public methodValidateVerifies that the given activity is valid. (Overrides DependencyObjectValidator.Validate(ValidationManager, Object).)
Public methodValidateActivityChangeWhen overridden in a derived class, validates a change based on a specified Activity being added or removed. This function is called during the application of changes that are made to the workflow during dynamic updates. (Inherited from Validator.)
Public methodValidatePropertiesHelper method to automatically validate the specific objects properties. (Inherited from Validator.)
Protected methodValidatePropertyPerforms validation on a property and returns a ValidationErrorCollection that contains the results of that validation. (Inherited from Validator.)

The following example shows a complete ActivityValidator used for a custom activity. The custom activity is a ConsoleWriteLineActivity activity that has a single dependency property named Msg of type String. The validator ensures that the Msg property is set. If it is not set, the compiler displays an error when the Validate(ValidationManager, Object) method is called on the ActivityValidator and the compilation fails.

class ConsoleWriteLineActivityValidator : ActivityValidator
    public override ValidationErrorCollection Validate(ValidationManager manager, object obj)
        // Invoke the base class method implementation to
        // perform default validation.
        ValidationErrorCollection errors = base.Validate(manager, obj);

        // Make sure there is an activity instance.
        ConsoleWriteLineActivity crw = obj as ConsoleWriteLineActivity;
        if (crw == null)
            throw new InvalidOperationException();

        // If the activity has no parent then this validation
        // is occurring during the compilation of the activity
        // and not during the hosting or creation of an
        // activity instance.
        if (crw.Parent == null)
            // Can skip the rest of the validation because
            // it deals with the hosting and the creation
            // of the activity.
            return errors;

        // Msg is required. Add a validation error if there is no
        // Msg specified or Msg is not bound to another property.
        if (string.IsNullOrEmpty(crw.Msg) &&
            crw.GetBinding(ConsoleWriteLineActivity.MsgProperty) == null)
            errors.Add(new ValidationError("Msg is required", 100, false, "Msg"));

        return errors;

.NET Framework

Supported in: 4, 3.5, 3.0

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.