ActivityValidator Class

Definition

public ref class ActivityValidator : System::Workflow::ComponentModel::Compiler::DependencyObjectValidator

public class ActivityValidator : System.Workflow.ComponentModel.Compiler.DependencyObjectValidator

[System.Obsolete("The System.Workflow.* types are deprecated.  Instead, please use the new types from System.Activities.*")]
public class ActivityValidator : System.Workflow.ComponentModel.Compiler.DependencyObjectValidator

type ActivityValidator = class
    inherit DependencyObjectValidator

[<System.Obsolete("The System.Workflow.* types are deprecated.  Instead, please use the new types from System.Activities.*")>]
type ActivityValidator = class
    inherit DependencyObjectValidator

Public Class ActivityValidator
Inherits DependencyObjectValidator

Inheritance

Object

Validator

DependencyObjectValidator

ActivityValidator

Derived

System.Workflow.Activities.CallExternalMethodActivityValidator

System.Workflow.Activities.HandleExternalEventActivityValidator

System.Workflow.ComponentModel.Compiler.CompositeActivityValidator

Attributes

ObsoleteAttribute

Examples

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 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;
    }
}

Class ConsoleWriteLineActivityValidator
    Inherits ActivityValidator

    Public Overrides Function Validate( _
        ByVal manager As System.Workflow.ComponentModel.Compiler.ValidationManager, _
        ByVal obj As Object) As System.Workflow.ComponentModel.Compiler.ValidationErrorCollection

        'Invoke the base class method implementation to
        'perform default validation.
        Dim errors As ValidationErrorCollection = MyBase.Validate(manager, obj)

        'Make sure there is an activity instance.
        Dim crw As ConsoleWriteLineActivity = CType(obj, ConsoleWriteLineActivity)
        If crw Is Nothing Then
            Throw New InvalidOperationException()
        End If

        '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 Is Nothing Then
            'Can skip the rest of the validation because
            'it deals with the hosting and the creation
            'of the activity.
            Return errors
        End If

        '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) And _
            crw.GetBinding(ConsoleWriteLineActivity.MsgProperty) Is Nothing Then

            errors.Add(New ValidationError("Msg is required", 100, False, "Msg"))

        End If

        Return errors
    End Function
End Class

Remarks

Constructors

Methods

Applies to