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//
// BackgroundWorker.cs
//
// Authors:
// Atsushi Enomoto <atsushi@ximian.com>
//
// Copyright (C) 2006 Novell, Inc.
//
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System.Collections.Generic;
using System.Threading;
namespace System.ComponentModel
{
#if !NET_2_1
[DefaultEvent ("DoWork")]
public class BackgroundWorker : Component
#else
public class BackgroundWorker
#endif
{
public BackgroundWorker ()
{
}
AsyncOperation async;
bool cancel_pending, report_progress = false, support_cancel = false, complete = false;
public event DoWorkEventHandler DoWork;
public event ProgressChangedEventHandler ProgressChanged;
public event RunWorkerCompletedEventHandler RunWorkerCompleted;
#if !NET_2_1
[Browsable (false)]
#endif
public bool CancellationPending {
get { return cancel_pending; }
}
#if !NET_2_1
[Browsable (false)]
#endif
public bool IsBusy {
get { return async != null; }
}
[DefaultValue (false)]
public bool WorkerReportsProgress {
get { return report_progress; }
set { report_progress = value; }
}
[DefaultValue (false)]
public bool WorkerSupportsCancellation {
get { return support_cancel; }
set { support_cancel = value; }
}
public void CancelAsync ()
{
if (!support_cancel)
throw new InvalidOperationException ("This background worker does not support cancellation.");
if (!IsBusy)
return;
cancel_pending = true;
}
public void ReportProgress (int percentProgress)
{
ReportProgress (percentProgress, null);
}
public void ReportProgress (int percentProgress, object userState)
{
if (!WorkerReportsProgress)
throw new InvalidOperationException ("This background worker does not report progress.");
if (complete)
throw new InvalidOperationException ("The background worker has ended.");
ProgressChangedEventArgs pcea = new ProgressChangedEventArgs (percentProgress, userState);
if (async == null) {
// we can report progress before a call to RunWorkerAsync - but we do it sync
OnProgressChanged (pcea);
} else {
async.Post (delegate (object o) {
ProgressChangedEventArgs e = o as ProgressChangedEventArgs;
OnProgressChanged (e);
}, pcea);
}
}
public void RunWorkerAsync ()
{
RunWorkerAsync (null);
}
delegate void ProcessWorkerEventHandler (object argument, AsyncOperation async, SendOrPostCallback callback);
void ProcessWorker (object argument, AsyncOperation async, SendOrPostCallback callback)
{
// do worker
Exception error = null;
DoWorkEventArgs e = new DoWorkEventArgs (argument);
try {
OnDoWork (e);
} catch (Exception ex) {
error = ex;
e.Cancel = false;
}
callback (new object [] {
new RunWorkerCompletedEventArgs (
e.Result, error, e.Cancel),
async});
}
void CompleteWorker (object state)
{
object [] args = (object []) state;
RunWorkerCompletedEventArgs e =
args [0] as RunWorkerCompletedEventArgs;
AsyncOperation async = args [1] as AsyncOperation;
SendOrPostCallback callback = delegate (object darg) {
this.async = null;
complete = true;
OnRunWorkerCompleted (darg as RunWorkerCompletedEventArgs);
};
async.PostOperationCompleted (callback, e);
cancel_pending = false;
}
public void RunWorkerAsync (object argument)
{
if (IsBusy)
throw new InvalidOperationException ("The background worker is busy.");
async = AsyncOperationManager.CreateOperation (this);
complete = false;
ProcessWorkerEventHandler handler =
new ProcessWorkerEventHandler (ProcessWorker);
handler.BeginInvoke (argument, async, CompleteWorker, null, null);
}
protected virtual void OnDoWork (DoWorkEventArgs e)
{
if (DoWork != null)
DoWork (this, e);
}
protected virtual void OnProgressChanged (ProgressChangedEventArgs e)
{
if (ProgressChanged != null)
ProgressChanged (this, e);
}
protected virtual void OnRunWorkerCompleted (RunWorkerCompletedEventArgs e)
{
if (RunWorkerCompleted != null)
RunWorkerCompleted (this, e);
}
}
}
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