Develop Reference

Threading lock in WinForms

I have a class that generates images in a thread and invokes an event on every frame. A Form subscribes to this event and displays the image in a PictureBox using Invoke.
If the image generation process is allowed to finish, all is good. However, if the Form is closed while the thread is running, the Form tries to stop the thread but ends up in some sort of a deadlock.
When I try to use the threaded class in without a Form or in a Console app, start the process, wait for a second, then Cancel it, everything works fine.
The question is, something must be wrong with either the Form_Closing method of the Form or the Stop method of the threaded class.
I have kept the code to a minimum and it can be pasted into LinqPad, etc.
An auxiliary question: Should the Process method invoke the Stop method to clean up?
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Reflection;
using System.Threading;
using System.Windows.Forms;
namespace VideoMask.WinFormsAppApp
{
internal static class Program
{
[STAThread]
private static void Main ()
{
Program.TestWithoutForm(); // Runs fine.
Program.TestWithForm(); // Deadlocks.
}
private static void TestWithForm ()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new FormMain());
}
private static void TestWithoutForm ()
{
new TestWithoutForm().Run();
}
}
public class TestWithoutForm
{
private VideoProcessor VideoProcessor = new VideoProcessor();
public TestWithoutForm ()
{
this.VideoProcessor.SourceFrameRead += this.VideoProcessor_SourceFrameRead;
}
public void Run ()
{
this.VideoProcessor.Start();
Thread.Sleep(1000);
this.VideoProcessor.Stop();
MessageBox.Show("Done");
}
private void VideoProcessor_SourceFrameRead (object sender, VideoProcessorEventArgs e)
{
var filename = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location), "Sample.png");
e.Bitmap.Save(filename, ImageFormat.Png);
}
}
public class FormMain: Form
{
private PictureBox PictureBox = new PictureBox();
private VideoProcessor VideoProcessor = new VideoProcessor();
public FormMain ()
{
this.Controls.Add(this.PictureBox);
this.PictureBox.Dock = DockStyle.Fill;
this.Shown += this.FormMain_Shown;
this.FormClosing += this.FormMain_FormClosing;
this.WindowState = FormWindowState.Maximized;
}
private void FormMain_Shown (object sender, EventArgs e)
{
this.VideoProcessor.SourceFrameRead += this.VideoProcessor_SourceFrameRead;
this.VideoProcessor.Start();
}
private void FormMain_FormClosing (object sender, FormClosingEventArgs e)
{
this.VideoProcessor.Stop();
this.VideoProcessor.Dispose();
this.VideoProcessor = null;
}
private void VideoProcessor_SourceFrameRead (object sender, VideoProcessorEventArgs e)
{
this.Invoke
(
new Action
(
() =>
{
using (var bitmap = this.PictureBox.Image)
{
this.PictureBox.Image = new Bitmap(e.Bitmap);
}
}
)
);
}
}
public sealed class VideoProcessor: IDisposable
{
public event EventHandler<ErrorEventArgs> ConversionError = null;
public event EventHandler<VideoProcessorEventArgs> SourceFrameRead = null;
private Font Font = null;
private Bitmap Bitmap = null;
private Thread Thread = null;
private Graphics Graphics = null;
private readonly object SyncRoot = new object();
private CancellationTokenSource CancellationTokenSource = null;
public VideoProcessor ()
{
this.Bitmap = new Bitmap(800, 600, PixelFormat.Format32bppArgb);
this.Graphics = Graphics.FromImage(this.Bitmap);
this.Font = new Font(FontFamily.GenericSansSerif, 48, GraphicsUnit.Point);
}
public bool IsRunning { get; private set; }
public void Start ()
{
lock (this.SyncRoot)
{
if (this.IsRunning) { throw (new Exception("A video conversion process is already running.")); }
this.Stop();
this.CancellationTokenSource = new CancellationTokenSource();
this.Thread = new Thread(new ParameterizedThreadStart(this.Process));
this.Thread.Start(this.CancellationTokenSource);
}
}
public void Stop ()
{
lock (this.SyncRoot)
{
if (!this.IsRunning) { return; }
this.CancellationTokenSource?.Cancel();
this.Thread.Join();
this.Thread = null;
this.CancellationTokenSource?.Dispose();
this.CancellationTokenSource = null;
}
}
private void Process (object cancellationTokenSource)
{
var source = (CancellationTokenSource) cancellationTokenSource ?? throw (new ArgumentNullException(nameof(cancellationTokenSource)));
lock (this.SyncRoot) { if (this.IsRunning) { throw (new Exception("A conversion process is already running.")); } }
this.IsRunning = true;
for (var i = 1; i <= int.MaxValue; i++)
{
if (source.IsCancellationRequested) { break; }
this.Graphics.Clear(Color.White);
this.Graphics.DrawString(i.ToString(), this.Font, Brushes.Black, 10, 10);
this.SourceFrameRead?.Invoke(this, new VideoProcessorEventArgs(this.Bitmap));
Thread.Sleep(33);
}
this.IsRunning = false;
}
public void Dispose () => this.Stop();
}
public class VideoProcessorEventArgs: EventArgs
{
public Bitmap Bitmap { get; private set; }
public VideoProcessorEventArgs (Bitmap bitmap) { this.Bitmap = bitmap; }
}
}

Fill list box from another thread

I'm searching for this for several hours now and was not able to find proper solution. I'm c# beginner.
I have a winforms app with a ListBox and a class that does some work and should run forever on separate thread. I want to push MyDataStruct to ListBox each time its created in WorkerClass.Work.
Later on, several WorkerClass instances should run simultaneously and I will have combobox to pick which instance data to feed to ListBox . Is it better to have WorkerClas return only single MyDataStruct and keep their queue in Form1 class or have a queue in each WorkerClass and exchange the entire queue with Form1 every time it changes?
is my void QueueToLb good way to add queue data to ListBox ?
thank you for your support.
public partial class Form1 : Form
{
Queue<MyDataStruct> qList;
MyDataStruct myDataStruct;
private void RunTask()
{
//how do I make MyLongTask to update either qList or myDataStuct
Task.Run(() =>
{
MyLongTask(0, 1000);
});
}
private void MyLongTask(int low, int high)
{
WorkerClass wc = new WorkerClass();
wc.Work(low,high);
}
private void QueueToLb()
{
//is this good way to update listbox from queue?
List<MyDataStruct> lstMds = qList.Reverse<MyDataStruct>().ToList<MyDataStruct>();
List<string> lstStr = new List<string>();
foreach (MyDataStruct m in lstMds)
{
lstStr.Add(m.ToString());
}
listBox1.DataSource = lstStr;
}
}
public class WorkerClass
{
Queue<MyDataStruct> qList; //not sure if its better to keep the queue here or in Form1
public WorkerClass()
{
qList = new Queue<MyDataStruct>();
}
public void Work(int low, int high) //does some work forever
{
while (true)
{
if (qList.Count > 11) qList.Dequeue();
MyDataStruct mds = new MyDataStruct();
Random random = new Random();
mds.dt = DateTime.Now;
mds.num = random.Next(low, high);
qList.Enqueue(mds);
Thread.Sleep(1000);
}
}
}
public class MyDataStruct
{
public DateTime dt;
public int num;
public override string ToString()
{
StringBuilder s = new StringBuilder();
s.Append(num.ToString());
s.Append(" - ");
s.Append(dt.ToShortDateString());
return s.ToString();
}
}
OK I think I figured how to use BackgroundWorker on this, I'll be happy if someone could verify it is correct
public partial class Form1 : Form
{
Queue<MyDataStruct> qList;
BackgroundWorker bw = new BackgroundWorker();
public Form1()
{
InitializeComponent();
bw.WorkerReportsProgress = true;
bw.DoWork += new DoWorkEventHandler(Bw_DoWork);
bw.ProgressChanged += new ProgressChangedEventHandler(bw_ProgressChanged);
}
private void Form1_Load(object sender, EventArgs e)
{
qList = new Queue<MyDataStruct>(12);
}
private void button1_Click(object sender, EventArgs e)
{
bw.RunWorkerAsync();
}
private void MyLongTask(int low = 0, int high = 1000)
{
WorkerClass wc = new WorkerClass(bw);
wc.Work(low,high);
}
private void BindToLbWithQueue()
{
MyDataStruct mds = new MyDataStruct();
Random random = new Random();
mds.dt = DateTime.Now;
mds.num = random.Next(0, 1000);
qList.Enqueue(mds);
QueueToLb();
}
private void QueueToLb()
{
//is this good way to update listbox from queue?
List<MyDataStruct> lstMds = qList.Reverse<MyDataStruct>().ToList<MyDataStruct>();
List<string> lstStr = new List<string>();
foreach (MyDataStruct m in lstMds)
{
lstStr.Add(m.ToString());
}
listBox1.DataSource = lstStr;
}
#region worker
private void Bw_DoWork(object sender, DoWorkEventArgs e)
{
MyLongTask();
}
private void bw_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
qList = (Queue<MyDataStruct>)e.UserState;
QueueToLb();
}
#endregion
}
public class WorkerClass
{
Queue<MyDataStruct> qList; //not sure if its better to keep the queue here or in Form1
BackgroundWorker bw = null;
public WorkerClass(BackgroundWorker bw)
{
this.bw = bw;
qList = new Queue<MyDataStruct>();
}
public void Work(int low, int high) //does some work forever
{
while (true)
{
if (qList.Count > 11) qList.Dequeue();
MyDataStruct mds = new MyDataStruct();
Random random = new Random();
mds.dt = DateTime.Now;
mds.num = random.Next(low, high);
qList.Enqueue(mds);
bw.ReportProgress(0, qList);
Thread.Sleep(1000);
}
}
}
public class MyDataStruct
{
public DateTime dt;
public int num;
public override string ToString()
{
StringBuilder s = new StringBuilder();
s.Append(num.ToString());
s.Append(" - ");
s.Append(dt.ToShortDateString());
return s.ToString();
}
}

Stop Timer in another class

I have a program that sends and receives messages over serial.
I have this Sender class:
public class Sender
{
private System.Timers.Timer _responseTimer;
public Sender(SerialPort sp)
{
_serialPort = sp;
_responseTimer = new System.Timers.Timer(2000);
}
public void Attach(ISenderObserver iso)
{
_responseTimer.Elapsed += new ElapsedEventHandler(iso.ResponseTooSlowEvent);
}
public void SendCommand(String command)
{
//start response timeout timer
_responseTimer.AutoReset = false;
_responseTimer.Enabled = true;
_serialPort.Write(command);
}
}
And then I have this receiving class:
public class Receiver : ISenderObserver
{
private static bool _continue;
private static SerialPort _serialPort;
private Thread _receiveThread;
public Receiver(SerialPort sp)
{
_serialPort = sp;
_continue = true;
_serialPort.Open();
//Start the receiving thread
_receiveThread = new Thread(Receive);
_receiveThread.Start();
}
public void Receive()
{
while (_continue)
{
String receivedMessage = _serialPort.ReadLine();
//parse received message
}
}
public void ResponseTooSlowEvent(object source, System.Timers.ElapsedEventArgs e)
{
Console.Write("\nToo Slow!");
}
}
And this interface:
public interface ISenderObserver
{
void ResponseTooSlowEvent(object source, ElapsedEventArgs e);
}
They are called like this in their main controller:
sender = new Sender(_serialPort);
receiver = new Receiver(_serialPort);
sender.Attach(receiver);
The reason for the timer is that I want the program to abort its waiting for a certain message if it takes too long, thereby avoiding a deadlock if it gets disconnected.
I thereby want to stop the timer within the Receiver-class as soon as line:
String receivedMessage = _serialPort.ReadLine();
is finished.
How can I do this without having dependencies all over the place?

C# Tasks - am I experiencing a suspicious increasing of number of handles

I am dipping my toes in Tasks (.NET 4.5) and am experiencing increasing handles (in task manager). I have a class doing a simple Play/Stop of audio file using MediaPlayer class (System.Windows.Media namespace). I have a second class which wraps it and exposes sync/async playback.
All is working fine and functionality is OK, but see the number of handles increasing in Task manager which worries me.... Am I doing something wrong here?
Important note: if I comment our the "await Task.Delay(1000);" --> then all is just fine and no leaks are observed... How come??
public partial class Form1 : Form
{
AudioActions syncAction = new AudioActions(#"c:\1.wav", false);
AudioActions asyncAction = new AudioActions(#"c:\1.wav", true);
public Form1()
{
InitializeComponent();
}
private async void syncPlayback(object sender, EventArgs e)
{
for (int i = 0; i < 10; i++)
{
await syncAction.Start();
}
}
private async void asyncPlayback(object sender, EventArgs e)
{
for (int i = 0; i < 100; i++)
{
await asyncAction.Start();
await Task.Delay(100); //remove this line and all is fine!!!!
asyncAction.Stop();
}
Console.WriteLine("done");
}
}
public class AudioActions
{
private Audio audio = null;
private TaskCompletionSource<bool> tcs = null;
private string pathToWaveFile;
private bool async;
public AudioActions(string pathToWaveFile, bool async)
{
this.pathToWaveFile=pathToWaveFile;
this.async=async;
}
public Task Start()
{
tcs = new TaskCompletionSource<bool>();
audio = new Audio();
audio.mediaPlayerPlaybackStoppedEvent += Audio_wmPlaybackStopped;
if (async)
tcs.TrySetResult(true); //since its async operation, lets return immediately and free the task from waiting
audio.PlayAudioFileInMediaPlayer(pathToWaveFile);
return tcs.Task;
}
private void Audio_wmPlaybackStopped()
{
audio.mediaPlayerPlaybackStoppedEvent -= Audio_wmPlaybackStopped;
tcs.TrySetResult(true); //playback stopped. Lets free the task from waiting
}
public void Stop()
{
audio.StopAudioFilePlaybackInMediaPlayer();
}
}
public class Audio
{
MediaPlayer mediaPlayer = null;
public delegate void MediaPlayerPlaybackStoppedDelegate();
public event MediaPlayerPlaybackStoppedDelegate mediaPlayerPlaybackStoppedEvent;
public void PlayAudioFileInMediaPlayer(string pathToWavFile)
{
mediaPlayer = new MediaPlayer();
mediaPlayer.MediaEnded += mediaPlayer_MediaEnded;
mediaPlayer.Open(new Uri(pathToWavFile));
mediaPlayer.Play();
}
void mediaPlayer_MediaEnded(object sender, EventArgs e)
{
mediaPlayerPlaybackStoppedEvent.Invoke();
MediaPlayer mediaPlayer = (MediaPlayer)sender;
mediaPlayer.MediaEnded -= mediaPlayer_MediaEnded;
mediaPlayer.Close();
mediaPlayer = null;
}
public void StopAudioFilePlaybackInMediaPlayer()
{
mediaPlayer.Stop();
mediaPlayer.Close();
mediaPlayer = null;
GC.Collect();
GC.WaitForPendingFinalizers();
GC.Collect();
}
}
Adding a strip down code:
private async void asyncPlayback(object sender, EventArgs e)
{
AudioActions asyncAction = new AudioActions();
for (int i = 0; i < 100; i++)
{
await asyncAction.Start();
await Task.Delay(1000); //remove this line and all is fine!!!!
asyncAction.Stop();
}
}
public class AudioActions
{
private Audio audio = null;
private TaskCompletionSource<bool> tcs = null;
public Task Start()
{
tcs = new TaskCompletionSource<bool>();
audio = new Audio();
tcs.TrySetResult(true); //since its async operation, lets return immediately and free the task from waiting
audio.PlayAudioFileInMediaPlayer(#"c:\1.wav");
return tcs.Task;
}
public void Stop()
{
audio.StopAudioFilePlaybackInMediaPlayer();
}
}
public class Audio
{
MediaPlayer mediaPlayer = null;
public void PlayAudioFileInMediaPlayer(string pathToWavFile)
{
mediaPlayer = new MediaPlayer();
mediaPlayer.Open(new Uri(pathToWavFile));
mediaPlayer.Play();
}
public void StopAudioFilePlaybackInMediaPlayer()
{
mediaPlayer.Stop();
mediaPlayer.Close();
mediaPlayer = null;
GC.Collect();
GC.WaitForPendingFinalizers();
GC.Collect();
}
}
Modified class solving the problem:
public class Audio
{
public delegate void NaudioPlaybackStoppedDelegate();
public event NaudioPlaybackStoppedDelegate naudioPlaybackStoppedEvent;
private WaveOut player = null;
public void PlayAudioFileUsingNaudio(string pathToWavFile)
{
player = new WaveOut();
AudioFileReader waveFileReader = new AudioFileReader(pathToWavFile);
player.Init(waveFileReader);
player.PlaybackStopped += NAudio_Stopped;
player.Play();
}
private void NAudio_Stopped(object sender, StoppedEventArgs e)
{
player.PlaybackStopped -= NAudio_Stopped;
if (naudioPlaybackStoppedEvent!=null)
naudioPlaybackStoppedEvent.Invoke();
player.Dispose();
}
public void StopAudioFilePlaybackInNaudio()
{
player.Stop();
}
}

Replacing MediaPlayer with NAudio 3rd party solved it.
public class Audio
{
public delegate void NaudioPlaybackStoppedDelegate();
public event NaudioPlaybackStoppedDelegate naudioPlaybackStoppedEvent;
private WaveOut player = null;
public void PlayAudioFileUsingNaudio(string pathToWavFile)
{
player = new WaveOut();
AudioFileReader waveFileReader = new AudioFileReader(pathToWavFile);
player.Init(waveFileReader);
player.PlaybackStopped += NAudio_Stopped;
player.Play();
}
private void NAudio_Stopped(object sender, StoppedEventArgs e)
{
player.PlaybackStopped -= NAudio_Stopped;
if (naudioPlaybackStoppedEvent!=null)
naudioPlaybackStoppedEvent.Invoke();
player.Dispose();
}
public void StopAudioFilePlaybackInNaudio()
{
player.Stop();
}
}

Updating UI from background thread issues

I'm coding a class to move and copy files. I'm raising events when the current file progress and the total progress changes. When I test the code on my XP machine, it works fine, but when I run it on my Windows 7 64-Bit machine, the current progress doesn't update the UI correctly. The current progress ProgressBar only gets half way then starts on the next file which does the same. The total progress ProgressBar updates fine. Any ideas why this is happening?
EDIT: The Windows 7 machine is running a quad-core and the XP is running a dual-core. Not sure if that might be what's making a difference. I'm only a hobbyist so excuse my ignorance :)
EDIT: Code added (Background)
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.IO;
using System.Threading;
using System.Timers;
using Timer = System.Timers.Timer;
namespace nGenSolutions.IO
{
public class FileTransporter
{
#region Delegates
public delegate void CurrentFileChangedEventHandler(string fileName);
public delegate void CurrentProgressChangedEventHandler(int percentComplete);
public delegate void CurrentWriteSpeedUpdatedEventHandler(long bytesPerSecond);
public delegate void TotalProgressChangedEventHandler(int percentComplete);
public delegate void TransportCompleteEventHandler(FileTransportResult result);
#endregion
private readonly List<string> _destinationFiles = new List<string>();
private readonly List<string> _sourceFiles = new List<string>();
private long _bytesCopiedSinceInterval;
private FileTransportResult _result;
private Timer _speedTimer;
private long _totalDataLength;
private BackgroundWorker _worker;
public bool TransportInProgress { get; private set; }
public event CurrentFileChangedEventHandler CurrentFileChanged;
public event CurrentProgressChangedEventHandler CurrentProgressChanged;
public event CurrentWriteSpeedUpdatedEventHandler CurrentWriteSpeedUpdated;
public event TotalProgressChangedEventHandler TotalProgressChanged;
public event TransportCompleteEventHandler TransportComplete;
public void AddFile(string sourceFile, string destinationFile)
{
if (!File.Exists(sourceFile))
throw new FileNotFoundException("The specified file does not exist!", sourceFile);
var fileInfo = new FileInfo(sourceFile);
_totalDataLength += fileInfo.Length;
_sourceFiles.Add(sourceFile);
_destinationFiles.Add(destinationFile);
}
public void BeginTransport()
{
// update the write speed every 3 seconds
_speedTimer = new Timer {Interval = 3000};
_speedTimer.Elapsed += SpeedTimerElapsed;
_worker = new BackgroundWorker();
_worker.DoWork += DoTransport;
_worker.RunWorkerCompleted += WorkerCompleted;
_worker.RunWorkerAsync();
_speedTimer.Start();
TransportInProgress = true;
}
private void SpeedTimerElapsed(object sender, ElapsedEventArgs e)
{
InvokeCurrentSpeedUpdated(_bytesCopiedSinceInterval);
_bytesCopiedSinceInterval = 0;
}
private void WorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
TransportInProgress = false;
InvokeTransportComplete(_result);
}
public void CancelTransport(bool rollbackChanges)
{
if (TransportInProgress == false)
throw new InvalidOperationException("You tried to stop the transport before you started it!");
_result = FileTransportResult.Cancelled;
_worker.CancelAsync();
while (_worker.IsBusy)
{
// wait for worker to die an 'orrible death
}
// TODO: rollback changes if requested
}
private void DoTransport(object sender, DoWorkEventArgs e)
{
long totalBytesCopied = 0;
int totalPercentComplete = 0;
for (int i = 0; i < _sourceFiles.Count; i++)
{
string sourceFile = _sourceFiles[i];
string destinationFile = _destinationFiles[i];
long currentFileLength = new FileInfo(sourceFile).Length;
InvokeCurrentFileChanged(sourceFile);
using (var sourceStream = new FileStream(sourceFile, FileMode.Open, FileAccess.Read))
{
using (var destinationStream = new FileStream(destinationFile, FileMode.Create, FileAccess.Write))
{
using (var reader = new BinaryReader(sourceStream))
{
using (var writer = new BinaryWriter(destinationStream))
{
int lastPercentComplete = 0;
for (int j = 0; j < currentFileLength; j++)
{
writer.Write(reader.ReadByte());
totalBytesCopied += 1;
_bytesCopiedSinceInterval += 1;
int current = Convert.ToInt32((j/(double) currentFileLength)*100);
int total = Convert.ToInt32((totalBytesCopied/(double) _totalDataLength)*100);
// raise progress events every 3%
if (current%3 == 0)
{
// only raise the event if the progress has increased
if (current > lastPercentComplete)
{
lastPercentComplete = current;
InvokeCurrentProgressChanged(lastPercentComplete);
}
}
if (total%3 == 0)
{
// only raise the event if the progress has increased
if (total > totalPercentComplete)
{
totalPercentComplete = total;
InvokeTotalProgressChanged(totalPercentComplete);
}
}
}
}
InvokeCurrentProgressChanged(100);
}
}
}
}
InvokeTotalProgressChanged(100);
}
private void InvokeCurrentFileChanged(string fileName)
{
CurrentFileChangedEventHandler handler = CurrentFileChanged;
if (handler == null) return;
handler(fileName);
}
private void InvokeCurrentProgressChanged(int percentComplete)
{
CurrentProgressChangedEventHandler handler = CurrentProgressChanged;
if (handler == null) return;
handler(percentComplete);
}
private void InvokeCurrentSpeedUpdated(long bytesPerSecond)
{
CurrentWriteSpeedUpdatedEventHandler handler = CurrentWriteSpeedUpdated;
if (handler == null) return;
handler(bytesPerSecond);
}
private void InvokeTotalProgressChanged(int percentComplete)
{
TotalProgressChangedEventHandler handler = TotalProgressChanged;
if (handler == null) return;
handler(percentComplete);
}
private void InvokeTransportComplete(FileTransportResult result)
{
TransportCompleteEventHandler handler = TransportComplete;
if (handler == null) return;
handler(result);
}
}
}
EDIT: Code added (GUI)
using System;
using System.IO;
using System.Windows.Forms;
using ExtensionMethods;
using nGenSolutions.IO;
namespace TestApplication
{
public partial class ProgressForm : Form
{
public ProgressForm()
{
InitializeComponent();
}
private void ProgressForm_Load(object sender, EventArgs e)
{
var transporter = new FileTransporter();
foreach (string fileName in Directory.GetFiles("C:\\Temp\\"))
{
transporter.AddFile(fileName, "C:\\" + Path.GetFileName(fileName));
}
transporter.CurrentFileChanged += transporter_CurrentFileChanged;
transporter.CurrentProgressChanged += transporter_CurrentProgressChanged;
transporter.TotalProgressChanged += transporter_TotalProgressChanged;
transporter.CurrentWriteSpeedUpdated += transporter_CurrentWriteSpeedUpdated;
transporter.TransportComplete += transporter_TransportComplete;
transporter.BeginTransport();
}
void transporter_TransportComplete(FileTransportResult result)
{
Close();
}
void transporter_CurrentWriteSpeedUpdated(long bytesPerSecond)
{
double megaBytesPerSecond = (double)bytesPerSecond/1024000;
currentSpeedLabel.SafeInvoke(x=> x.Text = string.Format("Transfer speed: {0:0.0} MB/s", megaBytesPerSecond));
}
private void transporter_TotalProgressChanged(int percentComplete)
{
totalProgressBar.SafeInvoke(x => x.Value = percentComplete);
}
private void transporter_CurrentProgressChanged(int percentComplete)
{
currentProgressBar.SafeInvoke(x => x.Value = percentComplete);
}
private void transporter_CurrentFileChanged(string fileName)
{
this.SafeInvoke(x => x.Text = string.Format("Current file: {0}", fileName));
}
}
}
EDIT: SafeInvoke code added
public static void SafeInvoke<T>(this T #this, Action<T> action) where T : Control
{
if (#this.InvokeRequired)
{
#this.Invoke(action, new object[] {#this});
}
else
{
if (!#this.IsHandleCreated) return;
if (#this.IsDisposed)
throw new ObjectDisposedException("#this is disposed.");
action(#this);
}
}

Well, if transporter_CurrentProgressChanged gets correct values, the program works properly. You can try to add some minimal Thread.Sleep call to InvokeCurrentProgressChanged (maybe with 0 parameter) when progress value is 100%, to get UI chance to update itself, but in this case you reduce the program performance. It is possibly better to leave the program unchanged, since it works as expected, and main progress bar is updated.