121 lines
3.9 KiB
C#
121 lines
3.9 KiB
C#
//-----------------------------------------------------------------------------
|
|
// Copyright (c) Microsoft Corporation. All rights reserved.
|
|
//-----------------------------------------------------------------------------
|
|
|
|
namespace System.Activities.Statements
|
|
{
|
|
using System;
|
|
using System.Activities;
|
|
using System.Activities.DynamicUpdate;
|
|
using System.Collections.Generic;
|
|
using System.Collections.ObjectModel;
|
|
using System.ComponentModel;
|
|
using System.Runtime.Collections;
|
|
using System.Windows.Markup;
|
|
|
|
[ContentProperty("Body")]
|
|
public sealed class CancellationScope : NativeActivity
|
|
{
|
|
Collection<Variable> variables;
|
|
Variable<bool> suppressCancel;
|
|
|
|
public CancellationScope()
|
|
: base()
|
|
{
|
|
this.suppressCancel = new Variable<bool>();
|
|
}
|
|
|
|
public Collection<Variable> Variables
|
|
{
|
|
get
|
|
{
|
|
if (this.variables == null)
|
|
{
|
|
this.variables = new ValidatingCollection<Variable>
|
|
{
|
|
// disallow null values
|
|
OnAddValidationCallback = item =>
|
|
{
|
|
if (item == null)
|
|
{
|
|
throw FxTrace.Exception.ArgumentNull("item");
|
|
}
|
|
}
|
|
};
|
|
}
|
|
return this.variables;
|
|
}
|
|
}
|
|
|
|
[DefaultValue(null)]
|
|
[DependsOn("Variables")]
|
|
public Activity Body
|
|
{
|
|
get;
|
|
set;
|
|
}
|
|
|
|
[DefaultValue(null)]
|
|
[DependsOn("Body")]
|
|
public Activity CancellationHandler
|
|
{
|
|
get;
|
|
set;
|
|
}
|
|
|
|
protected override void OnCreateDynamicUpdateMap(NativeActivityUpdateMapMetadata metadata, Activity originalActivity)
|
|
{
|
|
metadata.AllowUpdateInsideThisActivity();
|
|
}
|
|
|
|
protected override void CacheMetadata(NativeActivityMetadata metadata)
|
|
{
|
|
metadata.AddChild(this.Body);
|
|
metadata.AddChild(this.CancellationHandler);
|
|
metadata.SetVariablesCollection(this.Variables);
|
|
metadata.AddImplementationVariable(this.suppressCancel);
|
|
}
|
|
|
|
protected override void Execute(NativeActivityContext context)
|
|
{
|
|
if (this.Body != null)
|
|
{
|
|
context.ScheduleActivity(this.Body, new CompletionCallback(OnBodyComplete));
|
|
}
|
|
}
|
|
|
|
void OnBodyComplete(NativeActivityContext context, ActivityInstance completedInstance)
|
|
{
|
|
// Determine whether to run the Cancel based on whether the body
|
|
// canceled rather than whether cancel had been requested.
|
|
if (completedInstance.State == ActivityInstanceState.Canceled ||
|
|
(context.IsCancellationRequested && completedInstance.State == ActivityInstanceState.Faulted))
|
|
{
|
|
// We don't cancel the cancel handler
|
|
this.suppressCancel.Set(context, true);
|
|
|
|
context.MarkCanceled();
|
|
|
|
if (this.CancellationHandler != null)
|
|
{
|
|
context.ScheduleActivity(this.CancellationHandler, onFaulted: new FaultCallback(OnExceptionFromCancelHandler));
|
|
}
|
|
}
|
|
}
|
|
|
|
protected override void Cancel(NativeActivityContext context)
|
|
{
|
|
bool suppressCancel = this.suppressCancel.Get(context);
|
|
if (!suppressCancel)
|
|
{
|
|
context.CancelChildren();
|
|
}
|
|
}
|
|
|
|
void OnExceptionFromCancelHandler(NativeActivityFaultContext context, Exception propagatedException, ActivityInstance propagatedFrom)
|
|
{
|
|
this.suppressCancel.Set(context, false);
|
|
}
|
|
}
|
|
}
|