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C# code refactoring Background worker

On .NET Windows form, I have Background worker component that works fine. I have 5 forms, that has basically same Background worker on it with same code.
Can I extract this code to other class and somehow use it, considering this is an event? This is code I have on form. It takes 20 lines of code, and it would be nice if this can be refactored. Note: as you can see, I have already put it to other class BackgroundWorkerHelper, but can I also somehow refactor this events on Background worker, so that it is in other class as well, this way code is less and reused.
private void RunBackgroundWorker(string infoLabelText, int imageIndex)
{
BackgroundWorkerHelper.Run(backgroundWorker, progressBar, infoLabelText, imageIndex);
}
private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
BackgroundWorkerHelper.DoWork(backgroundWorker);
}
private void backgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
BackgroundWorkerHelper.ProgressChanged(sender, e, progressBar);
}
private void backgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
BackgroundWorkerHelper.RunWorkerCompleted(sender, e, progressBar);
}
Note: for now I would like to avoid using user control. I know I could do it, but then you have code that handles placing user control and so on. I am still not very good in it.

Here is solution, thanks to rory who gave me idea how to do it. First, I made this class:
public class BackgroundWorkerHelper
{
private static string _infoLabelText = string.Empty;
public BackgroundWorker _BackgroundWorker;
private BarEditItem _marqueeInfo;//this is marquee progress bar
public BackgroundWorkerHelper(BarEditItem marqueeInfo)
{
_marqueeInfo = marqueeInfo;
_BackgroundWorker = new BackgroundWorker();
_BackgroundWorker.WorkerReportsProgress = true;
_BackgroundWorker.WorkerSupportsCancellation = true;
_BackgroundWorker.DoWork += backgroundWorker_DoWork;
_BackgroundWorker.ProgressChanged += backgroundWorker_ProgressChanged;
_BackgroundWorker.RunWorkerCompleted += backgroundWorker_RunWorkerCompleted;
}
public void Run(string labelText, int imageIndex)
{
_marqueeInfo.Caption = labelText;
_marqueeInfo.ImageIndex = imageIndex;
if (!_BackgroundWorker.IsBusy)
_BackgroundWorker.RunWorkerAsync();
else
_marqueeInfo.Caption = "Busy processing saving data, please wait...";
}
public void DoWork()
{
for (int i = 0; i <= 5; i++)
{
_BackgroundWorker.ReportProgress(i); // call backgroundWorker_ProgressChanged event and pass i (which is e argument e.ProgressPercentage) to update UI controls
Thread.Sleep(250);
}
}
public void ProgressChanged(object sender, ProgressChangedEventArgs e)
{
_marqueeInfo.Visibility = BarItemVisibility.Always;
}
public void RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
_marqueeInfo.Visibility = BarItemVisibility.Never;
}
private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
DoWork();
}
private void backgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
ProgressChanged(sender, e);
}
private void backgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
RunWorkerCompleted(sender, e);
}
then in FORM, in class level above constructor place
private readonly BackgroundWorkerHelper _backgroundWorkerHelper;
then in Form Constructor instantiate class
_backgroundWorkerHelper = new BackgroundWorkerHelper(marqueeInfo);
and then I just call it in my form
_backgroundWorkerHelper.Run("Saving", 14);

BackgroundWorker Event Never Executes

I am attempting to use a Backgroundworker to keep my Main UI thread open and not freezing up. I am stepping thro my code and have set a breakpoint on both the backgroundWorker1.RunWorkerAsync(); which once hits just leaves the method and on the foreach line -> which is never hit.
What is the proper way to use a Backgroundworker?
public Form1()
{
InitializeComponent();
backgroundWorker1.WorkerReportsProgress = true;
backgroundWorker1.WorkerSupportsCancellation = true;
}
private void btnQuery_Click(object sender, EventArgs e)
{
grid1.Rows.Clear();
backgroundWorker1.RunWorkerAsync();
}
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
foreach (string name in studentRoster)
{
InsertIntoDB();
}
}

Here is your code with the handlers added and some comments.
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
backgroundWorker1.WorkerReportsProgress = true;
backgroundWorker1.WorkerSupportsCancellation = true;
backgroundWorker1.DoWork += new DoWorkEventHandler(BackgroundWorker_DoWork);
backgroundWorker1.ProgressChanged += new ProgressChangedEventHandler(BackgroundWorker_ProgressChanged);
backgroundWorker1.RunWorkerCompleted += new RunWorkerCompletedEventHandler(BackgroundWorker_RunWorkerCompleted);
}
private void btnQuery_Click(object sender, EventArgs e)
{
grid1.Rows.Clear();
backgroundWorker1.RunWorkerAsync();
}
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
foreach (string name in studentRoster)
{
InsertIntoDB();
// You can report progress by calling the following function.
//backgroundWorker1.ReportProgress(int percentProgress, object userState)
// You can set the percentProgress to any valid integer value,
// and userState can be any object you want.
// You can also check to see if this operation has been sent a request to cancel.
if (backgroundWorker1.CancellationPending)
{
e.Cancel = true;
return;
}
}
// You can send information back to the main thread by setting e.Result to any object you want.
}
private void BackgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
// Do something with the event that is being raised.
// To pass a value back through to this event, use the percentProgress and userState
// parameters of the ReportProgress function.
// the userState object that you pass will be received here as e.UserState
}
private void BackgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
// This event is raised by the background worker when the DoWork method is completed.
// You can receive information back from the worker thread by evaluating e.Result
}
}
}

How can I make a winform button "do something" as long as I am pressing the button?

I have tried all day, and looked up all kinds of ideas... with no real help.
When I press a button, like "JOG", which would move a CNC Machine axis continuously, as long a the button is pressed, then when released, it would stop.
To test this I am using a "picuture / LED" which when I press and hold, should be on... and when I release, it should turn off.
Pressed Button should = only while pressed, do something.
Release of same button = stop doing whatever you were doing now.
I am sure for you advanced folks, this is maybe 101... but for me... it is eating my lunch... help?

You can use the MouseDown and MouseUp events. When the MouseDown event is hit, call a method that loops and performs your action. Once MouseUp is hit, stop the loop.
private bool _run = false;
public void button_MouseDown(object sender, EventArgs e)
{
_run = true;
MyAction();
}
public void button_MouseUp(object sender, EventArgs e)
{
_run = false;
}
public void MyAction()
{
while(_run)
{
//You actions
}
}
Note that the above example will hog up the UI thread. You should run it on another thread using a BackgroundWorker or something similar.

Generically, have a look at the mouse up and down events. I would have it call some function asynchronously (not on the UI thread) when the mouse is down. And stop it when the mouse up event fires. System.Threading has some nice models for this. Try googling around there.
You are wanting to start and stop a thread where the procedure is looping performing your action.

I'd make my own subclass, something like this:
public class RepeatButton : Button
{
readonly Timer timer = new Timer();
public event EventHandler Depressed;
public virtual TimeSpan Interval
{
get { return TimeSpan.FromMilliseconds(timer.Interval); }
set { timer.Interval = (int)value.TotalMilliseconds; }
}
public RepeatButton()
{
timer.Interval = 100;
timer.Tick += delegate { OnDepressed(); };
}
protected override void OnMouseUp(MouseEventArgs e)
{
base.OnMouseUp(e);
timer.Stop();
}
protected override void OnMouseDown(MouseEventArgs e)
{
base.OnMouseDown(e);
timer.Start();
}
protected virtual void OnDepressed()
{
var handler = this.Depressed;
if (handler != null)
handler(this, EventArgs.Empty);
}
}
This allows your code to be asynchronous but also the Depressed event would be invoked on the UI thread still.

Consider Space bar to trigger button down and up as well.
this.button1.MouseDown += new System.Windows.Forms.MouseEventHandler(this.button1_MouseDown);
this.button1.MouseUp += new System.Windows.Forms.MouseEventHandler(this.button1_MouseUp);
this.button1.KeyDown += new System.Windows.Forms.KeyEventHandler(this.button1_KeyDown);
this.button1.KeyUp += new System.Windows.Forms.KeyEventHandler(this.button1_KeyUp);
private void button1_MouseDown(object sender, MouseEventArgs e)
{
led18.Show();
}
private void button1_MouseUp(object sender, MouseEventArgs e)
{
led18.Hide();
}
private void button1_KeyDown(object sender, KeyEventArgs e)
{
if(e.KeyCode == Keys.Space && e.Alt==false && e.Control==false && e.Shift==false)
{
led18.Show();
}
}
private void button1_KeyUp(object sender, KeyEventArgs e)
{
led18.Hide();
}

Thanks all, this is about as simple as I could get it.
Button and Mouse control mixed togather, needs mouse handling... which is added in the button properties, which will add the code to the designer.
private void button2_MouseDown(object sender, MouseEventArgs e)
{
led18.Show();
}
private void button2_MouseUp(object sender, MouseEventArgs e)
{
led18.Hide();
}
//below get automatically put into the design file...
this.button1.MouseDown += new System.Windows.Forms.MouseEventHandler(this.button1_MouseDown);
this.button1.MouseUp += new System.Windows.Forms.MouseEventHandler(this.button1_MouseUp);

Stop long running events

I have a following form Form3 that is opened by another form Form1, and when closed Form1 opens back up.
The problem is when I close Form3 DoSomething keeps running after form is closed.
I understand that I can make DoSomething into a thread and set IsBackground = true but is there another way to stop all processes when form closes.
This code is just example, For illustration.
public partial class Form3 : Form
{
public Form3()
{
InitializeComponent();
}
private void DoSomething()
{
int i = 0;
while(true)
{
if (!this.IsDisposed)
{
Application.DoEvents();
i++;
Thread.Sleep(10);
label1.Text = i.ToString();
dataGridView1.Rows.Add();
}
}
}
private void button1_Click(object sender, EventArgs e)
{
DoSomething();
}
private void Form3_FormClosed(object sender, FormClosedEventArgs e)
{
this.Dispose();
Form1.Default.Show();
}
}

You never break out of the while(true). You should either break the loop when it's IsDisposed is true, change your while loop to while(!IsDisposed), or store use a class level variable that determines when to break the loop.
I would probably opt for the latter, as it gives you a little more control.
public partial class Form3 : Form
{
volatile bool clDoSomething;
public Form3()
{
InitializeComponent();
}
private void DoSomething()
{
int i = 0;
clDoSomething = true;
while(clDoSomething)
{
Application.DoEvents();
++i;
Thread.Sleep(10);
label1.Text = i.ToString();
dataGridView1.Rows.Add();
}
}
private void button1_Click(object sender, EventArgs e)
{
DoSomething();
}
private void Form3_FormClosed(object sender, FormClosedEventArgs e)
{
clDoSomething = false;
Form1.Default.Show();
}
}

Your fundamental approach is flawed.
First off, Application.DoEvents should be avoided unless you are sure that you really need it, and that you are using it correctly. You do not need it here, and you are not using it correctly.
What you really need here is a Timer.
private Timer timer = new Timer();
private int count = 0;
public Form3()
{
InitializeComponent();
timer.Tick += timer_Tick;
timer.Interval = 10;
//when the form is closed stop the timer.
FormClosed += (_, args) => timer.Stop();
}
private void button1_Click(object sender, EventArgs e)
{
count = 0;
timer.Start();
}
private void timer_Tick(object sender, EventArgs e)
{
count++;
label1.Text = count.ToString();
dataGridView1.Rows.Add();
}
When the Form is create the Timer is configured. The tick event is set, along with the interval. The tick event will look similar to your DoSomething method; it will involve running some bit of code every 10 seconds, from the UI thread, while keeping the UI responsive. When the form is closed simply stop the timer and it will stop firing off these events.
Also note that in this example here pressing the button multiple times simply resets the timer and the count, it doesn't end up creating two loops that each fire every 10 milliseconds.

Override this.Dispose() or this.Close() as appropriate and kill off DoSomething() manually.

Thanks to cdhowie suggestions and input of all others. Mowing DoEvents to the end and adding IsDipsosed solved my problem.
public partial class Form3 : Form
{
public Form3()
{
InitializeComponent();
}
private void DoSomething()
{
int i = 0;
while ((true) && !this.IsDisposed)
{
i++;
Thread.Sleep(10);
label1.Text = i.ToString();
dataGridView1.Rows.Add();
Application.DoEvents();
}
}
private void button1_Click(object sender, EventArgs e)
{
DoSomething();
}
private void Form3_FormClosed(object sender, FormClosedEventArgs e)
{
Form1.Default.Show();
}
}

try to add this intsruction in the FormClosing event :
System.Diagnostics.Process.GetCurrentProcess().Kill();
it's a little bit like this:
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
System.Diagnostics.Process.GetCurrentProcess().Kill();
}

updating gui from another class c#

hey i am new to c# plz help.
i am writing a program that sorts data in a file and it is a time consuming process so i thought that i should run it in a separate thread and since it has alot of step so i made a new class for it. the problem is that i want to show the progress in the main GUI and i know for that i have to use Invoke function but the problem is that the form control variables are not accessible it this class. what should i do ??????
sample code:
public class Sorter
{
private string _path;
public Sorter(string path)
{
_path = path;
}
public void StartSort()
{
try
{
processFiles(_path, "h4x0r"); // Just kidding
}
catch (Exception e)
{
MessageBox.Show("Error: " + e.ToString(), "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
private void processFiles(string Dir, string[] key)
{
/* sorting program */
}
and it is used as
public partial class Form1 : Form
{
Sorter sort;
public Form1()
{
InitializeComponent();
}
private void browseBtn_Click(object sender, EventArgs e)
{
if (folderBrowserDialog1.ShowDialog() == DialogResult.OK)
textBox1.Text = folderBrowserDialog1.SelectedPath;
}
private void startBtn_Click(object sender, EventArgs e)
{
if (startBtn.Text == "Start Sorting")
{
Thread worker = new Thread(new ThreadStart(delegate() {
sort = new Sorter(textBox1.Text);
sort.StartSort(); }));
worker.start();
}
else
MessageBox.Show("Cancel");//TODO: add cancelling code here
}
}
plz help..

Add an Event to your class that is doing the multi-threaded work, that triggers when the progress changes. Have your form subscribe to this event and update the progress bar.
Note ProgressEventArgs is a little class that inherits EventArgs and has an Integer for the progress.
// delegate to update progress
public delegate void ProgressChangedEventHandler(Object sender, ProgressEventArgs e);
// Event added to your worker class.
public event ProgressChangedEventHandler ProgressUpdateEvent
// Method to raise the event
public void UpdateProgress(object sender, ProgressEventArgs e)
{
ProgressChangedEventHandler handler;
lock (progressUpdateEventLock)
{
handler = progressUpdateEvent;
}
if (handler != null)
handler(sender, e);
}

I would recommend you read up on the BackgroundWorker class. It is exactly for the problem you are trying to solve and makes things a lot easier than doing manual threading yourself.
Brief Example
public Form1()
{
InitializeComponent();
backgroundWorker.WorkerReportsProgress = true;
backgroundWorker.WorkerSupportsCancellation = true;
backgroundWorker.ProgressChanged += new ProgressChangedEventHandler(backgroundWorker_ProgressChanged);
}
void backgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
progressBar1.Value = e.ProgressPercentage;
}
private void btnStart_Click(object sender, EventArgs e)
{
if (!backgroundWorker.IsBusy)
backgroundWorker.RunWorkerAsync();
}
private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
for (int i = 1; i < 101; ++i)
{
if (backgroundWorker.CancellationPending)
{
e.Cancel = true;
break;
}
else
{
//Sort Logic is in here.
Thread.Sleep(250);
backgroundWorker.ReportProgress(i);
}
}
}
private void btnCancel_Click(object sender, EventArgs e)
{
if (backgroundWorker.IsBusy && backgroundWorker.WorkerSupportsCancellation)
backgroundWorker.CancelAsync();
}

You could do something like this:
public delegate void StatusReporter(double progressPercentage);
public class MainClass
{
public void MainMethod()
{
Worker worker = new Worker(ReportProgress);
ThreadStart start = worker.DoWork;
Thread workThread = new Thread(start);
workThread.Start();
}
private void ReportProgress(double progressPercentage)
{
//Report here!!!
}
}
public class Worker
{
private readonly StatusReporter _reportProgress;
public Worker(StatusReporter reportProgress)
{
_reportProgress = reportProgress;
}
public void DoWork()
{
for (int i = 0; i < 100; i++ )
{
// WORK, WORK, WORK
_reportProgress(i);
}
}
}

There are a few option available to solve this sort of issue. In any case, you will have to fiddle with Invoke to get the UI to update.
You could...
...add an event that fires on your new class which your UI can listen to, and Invoke as applicable - you'd still need to pass the data to your worker class (by constructor, properties, method call, etc)
...keep the method as a method on your form, and pas that to start your new thread from (after all, a new thread doesn't have to be starting in a different class)
...change the access modifiers on your controls to be (say) internal such that any class within the same assembly can Invoke changes to the controls, or read from them.
...make your worker class a child of the form it needs to access - it can then see the privates of its parent, as long as it is passed a reference to the instance.