While.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / WF / Activities / While.cs / 1305376 / While.cs
                        
                        
                            namespace System.Workflow.Activities 
{
    #region Imports

    using System; 
    using System.Text;
    using System.Reflection; 
    using System.Collections; 
    using System.CodeDom;
    using System.ComponentModel; 
    using System.ComponentModel.Design;
    using System.ComponentModel.Design.Serialization;
    using System.Drawing;
    using System.Workflow.ComponentModel; 
    using System.Workflow.ComponentModel.Design;
    using System.Collections.Generic; 
    using System.Workflow.ComponentModel.Compiler; 
    using System.Workflow.Activities.Common;
 
    #endregion

    [SRDescription(SR.WhileActivityDescription)]
    [ToolboxItem(typeof(ActivityToolboxItem))] 
    [Designer(typeof(WhileDesigner), typeof(IDesigner))]
    [ActivityValidator(typeof(WhileValidator))] 
    [ToolboxBitmap(typeof(WhileActivity), "Resources.While.png")] 
    public sealed class WhileActivity : CompositeActivity, IActivityEventListener
    { 
        #region Dependency Properties
        //metadata properties go here
        public static readonly DependencyProperty ConditionProperty = DependencyProperty.Register("Condition", typeof(ActivityCondition), typeof(WhileActivity), new PropertyMetadata(DependencyPropertyOptions.Metadata, new Attribute[] { new ValidationOptionAttribute(ValidationOption.Required) }));
        #endregion 

        #region Constructors 
 
        public WhileActivity()
        { 
        }

        public WhileActivity(string name)
            : base(name) 
        {
        } 
 
        #endregion
 
        #region Public Properties
        [SRCategory(SR.Conditions)]
        [SRDescription(SR.WhileConditionDescr)]
        public ActivityCondition Condition 
        {
            get 
            { 
                return base.GetValue(ConditionProperty) as ActivityCondition;
            } 
            set
            {
                base.SetValue(ConditionProperty, value);
            } 
        }
 
        [Browsable(false)] 
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        public Activity DynamicActivity 
        {
            get
            {
                if (this.EnabledActivities.Count > 0) 
                {
                    Activity[] dynamicChildren = this.GetDynamicActivities(this.EnabledActivities[0]); 
                    if (dynamicChildren.Length != 0) 
                        return dynamicChildren[0];
                } 
                return null;
            }
        }
        #endregion 

        #region Protected Methods 
        protected override ActivityExecutionStatus Execute(ActivityExecutionContext executionContext) 
        {
            if (executionContext == null) 
                throw new ArgumentNullException("executionContext");

            if (TryNextIteration(executionContext))
                return ActivityExecutionStatus.Executing; 

            return ActivityExecutionStatus.Closed; 
        } 
        protected override ActivityExecutionStatus Cancel(ActivityExecutionContext executionContext)
        { 
            if (executionContext == null)
                throw new ArgumentNullException("executionContext");

            if (this.EnabledActivities.Count == 0) 
                return ActivityExecutionStatus.Closed;
 
            Activity childActivity = this.EnabledActivities[0]; 
            ActivityExecutionContextManager contextManager = executionContext.ExecutionContextManager;
            ActivityExecutionContext childContext = contextManager.GetExecutionContext(childActivity); 

            if (childContext != null)
            {
                if (childContext.Activity.ExecutionStatus == ActivityExecutionStatus.Executing) 
                    childContext.CancelActivity(childContext.Activity);
 
                return ActivityExecutionStatus.Canceling; 
            }
            return ActivityExecutionStatus.Closed; 
        }
        #endregion

        #region Private Implementations 
        private bool TryNextIteration(ActivityExecutionContext context)
        { 
            if (this.ExecutionStatus == ActivityExecutionStatus.Canceling || this.ExecutionStatus == ActivityExecutionStatus.Faulting || !this.Condition.Evaluate(this, context)) 
                return false;
            else 
            {
                if (this.EnabledActivities.Count > 0)
                {
                    ActivityExecutionContextManager contextManager = context.ExecutionContextManager; 
                    ActivityExecutionContext innerContext = contextManager.CreateExecutionContext(this.EnabledActivities[0]);
                    innerContext.Activity.RegisterForStatusChange(Activity.ClosedEvent, this); 
                    innerContext.ExecuteActivity(innerContext.Activity); 
                }
                else 
                {
                    System.Diagnostics.Debug.Assert(false);
                }
                return true; 
            }
        } 
        #endregion 

        #region IActivityEventListener Members 
        void IActivityEventListener.OnEvent(object sender, ActivityExecutionStatusChangedEventArgs e)
        {
            if (e == null)
                throw new ArgumentNullException("e"); 
            if (sender == null)
                throw new ArgumentNullException("sender"); 
 
            ActivityExecutionContext context = sender as ActivityExecutionContext;
 
            if (context == null)
                throw new ArgumentException(SR.Error_SenderMustBeActivityExecutionContext, "sender");

            e.Activity.UnregisterForStatusChange(Activity.ClosedEvent, this); 
            ActivityExecutionContextManager contextManager = context.ExecutionContextManager;
            contextManager.CompleteExecutionContext(contextManager.GetExecutionContext(e.Activity)); 
 
            if (!TryNextIteration(context))
                context.CloseActivity(); 
        }
        #endregion
    }
 
    #region Validator
    internal sealed class WhileValidator : CompositeActivityValidator 
    { 
        public override ValidationErrorCollection Validate(ValidationManager manager, object obj)
        { 
            ValidationErrorCollection validationErrors = new ValidationErrorCollection(base.Validate(manager, obj));

            WhileActivity whileActivity = obj as WhileActivity;
            if (whileActivity == null) 
                throw new ArgumentException(SR.GetString(SR.Error_UnexpectedArgumentType, typeof(WhileActivity).FullName), "obj");
            if(whileActivity.EnabledActivities.Count != 1) 
                validationErrors.Add(new ValidationError(SR.GetString(SR.Error_WhileShouldHaveOneChild), ErrorNumbers.Error_WhileShouldHaveOneChild)); 

            return validationErrors; 
        }

        public override ValidationError ValidateActivityChange(Activity activity, ActivityChangeAction action)
        { 
            if (activity == null)
                throw new ArgumentNullException("activity"); 
            if (action == null) 
                throw new ArgumentNullException("action");
 
            if (activity.ExecutionStatus != ActivityExecutionStatus.Initialized &&
                activity.ExecutionStatus != ActivityExecutionStatus.Executing &&
                activity.ExecutionStatus != ActivityExecutionStatus.Closed)
            { 
                return new ValidationError(SR.GetString(SR.Error_DynamicActivity2, activity.QualifiedName, Enum.GetName(typeof(ActivityExecutionStatus), activity.ExecutionStatus), activity.GetType().FullName), ErrorNumbers.Error_DynamicActivity2);
            } 
            return null; 
        }
    } 
    #endregion
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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While.cs source code in C# .NET

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