Develop Reference

Why is the event RunWorkerCompletedEventArgs launched before I finished loading the progress bar in its entirety?

When I'm running a heavy task or a few data, at the end of the task the label showing the percentage reaches 100% correctly and displays the finalized message, but even the progressBar has not loaded in its entirety, when the completion message is displayed you can see the animation of the progress bar that completes your work.
I have not been able to solve this problem, and the natural way that a progress bar should work as in all the systems that I have seen, the progress is completed and then show a finished message.
Here I leave an example:
BackgroundWorker bg = new BackgroundWorker();
private void btnRun_Click(object sender, EventArgs e)
{
bg.WorkerReportsProgress = true;
bg.ProgressChanged += bg_ProgressChanged;
bg.DoWork += bg_DoWork;
bg.RunWorkerCompleted += bg_RunWorkerCompleted;
bg.RunWorkerAsync();
label1.Visible = true;
progressBar1.Visible = true;
}
Dowork Event:
private void bg_DoWork(object sender, DoWorkEventArgs e)
{
int progress = 0, percent = 0;
for (int i = 0; i < ds.Tables[0].Rows.Count; i++) //Cycle that will represent the heavy task
{
totalRecords = ds.Tables[0].Rows.Count;
progress++;
percent = Convert.ToInt16((((double)progress / (double)totalRecords ) * 100.00));
System.Threading.Thread.Sleep(500);
bg.ReportProgress(percent );
}
}
ProgressChanged
private void bg_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
// Change the value of the ProgressBar to the BackgroundWorker progress.
progressBar1.Step = 1;
progressBar1.Style = ProgressBarStyle.Continuous;
progressBar1.Minimum = 0;
progressBar1.Maximum = 100;
if (e.ProgressPercentage > 100)
{
label1.Text = "100%";
progressBar1.Value = progressBar1.Maximum;
}
else
{
label1.Text = Convert.ToString(e.ProgressPercentage) + "%";
progressBar1.Value = e.ProgressPercentage;
}
}
Finally, the RunWorkerCompleted event that is executed when the BackgroundWorker has finished:
private void bg_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
MessageBox.Show("Done...");
label1.Visible = false;
progressBar1.Visible = false;
}
How can I solve this progress bar animation problem?
Environment: Visual Studio 2010 (WindowsForms) & .NET NetFramework 4.

I think you're facing a classic problem of Windows' Aero animations.
Informations extracted from this page.
This lag happens when a progress bar is incremented. But it doesn't happen when the progress bar is decremented.
So basically, what you want to do is move past the actual value you should get to, then decrement to the actual value.
The author of the page uses an extension method, feel free to do as well; I'm just putting the relevant code here:
// To get around the progressive animation, we need to move the
// progress bar backwards.
if (value == pb.Maximum)
{
// Special case as value can't be set greater than Maximum.
pb.Maximum = value + 1; // Temporarily increase Maximum
pb.Value = value + 1; // Move past
pb.Maximum = value; // Reset maximum
}
else
{
pb.Value = value + 1; // Move past
}
pb.Value = value;

How to use progressbar.value property at different locations of program

I need to use progressbar.value property at different locations. But the problem is, while executing it shows only maximum value given. I need to stop at 25% and 75% and after some delay, 100%. How can I overcome this problem. Thanks in Advance...
C#
namespace ProgressBarWindowForm
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public void Form1_Load(object sender, System.EventArgs e)
{
label1.Hide();
progressBar1.Minimum = 0;
progressBar1.Maximum = 100;
}
private void button1_Click(object sender, EventArgs e)
{
progressBar1.Value = 25;
if (progressBar1.Value == 25)
{
label1.Show();
label1.Text = "Process Complete 25%";
}
progressBar1.Value = 75;
if (progressBar1.Value == 75)
{
label1.Show();
label1.Text = "Process Complete 75%";
}
}
}
}
Progressbar control name is progressBar1,
Label name is label1 and
Button name is button1
When I Clicked the Button, progressbar value is directly filling with 75%. I want to stop it at 25% and after some delay it should fill 75% and then 100%...Can anyone help..Can I use "progressBar1.value" only Once or as many times I need?

try this,Drag and drop background worker in windows form
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
backgroundWorker1.WorkerReportsProgress = true;
// This event will be raised on the worker thread when the worker starts
backgroundWorker1.DoWork += new DoWorkEventHandler(backgroundWorker1_DoWork);
// This event will be raised when we call ReportProgress
backgroundWorker1.ProgressChanged += new ProgressChangedEventHandler(backgroundWorker1_ProgressChanged);
}
private void button1_Click(object sender, EventArgs e)
{
// Start the background worker
backgroundWorker1.RunWorkerAsync();
}
// On worker thread so do our thing!
void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
// Your background task goes here
for (int i = 0; i <= 100; i++)
{
// Report progress to 'UI' thread
backgroundWorker1.ReportProgress(i);
// Simulate long task
if (label1.InvokeRequired)
{
label1.Invoke(new MethodInvoker(delegate
{
label1.Show();
label1.Text = "Process Complete " + progressBar1.Value + "%";
}));
}
if (progressBar1.Value == 25 || progressBar1.Value == 75)
{
System.Threading.Thread.Sleep(1000);
}
System.Threading.Thread.Sleep(100);
}
}
// Back on the 'UI' thread so we can update the progress bar
void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
// The progress percentage is a property of e
progressBar1.Value = e.ProgressPercentage;
}
}

Use a Timer to update the progress bar after a delay:
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
timer.Tick += Timer_Tick;
timer.Interval = 1000; // delay: 1000 milliseconds
}
Timer timer = new Timer();
private void Timer_Tick(object sender, EventArgs e)
{
if (progressBar1.Value == 100)
{
timer.Stop();
return;
}
progressBar1.Value += 25;
}
private void button1_Click(object sender, EventArgs e)
{
progressBar1.Value = 25;
timer.Start();
}
}

Its simple to update progressBar values in button click, you can initialize the properties in the page load or else use the designer, in page load it would be like the following:
private int ProgressPercentage = 10;
public void Form1_Load(object sender, System.EventArgs e)
{
progressBar1.Minimum = 0;
progressBar1.Maximum = 100;
progressBar1.Value = 0;
}
So the initialization completed, now you can code the button click like the following, through which you can update the progress bar in every button click:
private void button1_Click(object sender, EventArgs e)
{
progressBar1.Value += ProgressPercentage;
label1.Text = String.Format("Process Complete {0}%",progressBar1.Value);
}
If you want the update to be happens automatically in a particular interval means you can make use of a timer and enable the timer in the button click. Here you can find a similar thread which can be used to implement timer to your scene.
Update as per your comment, calling a delay will not be a best practice, you can make use a timer here as like the following:
System.Windows.Forms.Timer proTimer = new System.Windows.Forms.Timer();
private void Form1_Load(object sender, EventArgs e)
{
proTimer.Interval = 1000;
progressBar1.Minimum = 0;
progressBar1.Maximum = 100;
progressBar1.Value = 0;
proTimer.Tick += new EventHandler(proTimer_Tick);
}
private void button1_Click(object sender, EventArgs e)
{
proTimer.Enabled = true;
proTimer.Start();
}
// Timer event
void proTimer_Tick(object sender, EventArgs e)
{
progressBar1.Value += ProgressPercentage;
label1.Text = String.Format("Process Complete {0}%",progressBar1.Value);
if (progressBar1.Value == 100)
{
proTimer.Stop();
proTimer.Enbled = false;
}
}

You need to add a delay inbetween the changes. As of now, the button advance the bar to 25, sets the label, then advances the bar to 75 without pausing.
System.Threading.Thread.Sleep(n); will sleep n milliseconds, which you will need after the statement setting the 25 percent marker.
EDIT
If you want it the value to only progress on a button click, you will need to check the value of the progress bar before you advance it.
In pseudo code, something like:
onclick() {
if (progress == 0) {
progress = 25
label = the25MarkText
} else if (progress == 25) {
progress = 75
label = the75MarkText
}
}

How do I keep a BackgroundWorker from blocking the UI thread?

In my XML editor I want to be able to open multiple files at once using an index file. Obviously, depending on the amount of files, this can take a bit of time and I want to use a progress bar to notify the user that the programm is still loading and doing something.
From what I have researched the way to keep the UI progress bar updated is using a BackgroundWorker.
public MainWindow()
{
InitializeComponent();
tabList = new ObservableCollection<FileTab>();
tabControl.ItemsSource = tabList;
backgroundWorker = new BackgroundWorker();
backgroundWorker.DoWork += backgroundWorker_DoWork;
backgroundWorker.ProgressChanged += backgroundWorker_ProgressChanged;
backgroundWorker.RunWorkerCompleted += backgroundWorker_RunWorkerCompleted;
backgroundWorker.WorkerReportsProgress = true;
}
(...)
private void OpenProjectButtonClick(object sender, RoutedEventArgs e)
{
openingProgressBar.Value = 0;
openingProgressBar.Visibility = System.Windows.Visibility.Visible;
backgroundWorker.RunWorkerAsync();
}
void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
int i = 0;
foreach (IndexFile file in indexManager.fileList)
{
this.Dispatcher.Invoke((Action)(() =>
{
tabList.Add(new FileTab(file.filePath));
}));
i++;
Console.WriteLine("-(DoWork)->" + i);
double percentage = (Convert.ToDouble(i) / Convert.ToDouble(indexManager.fileList.Count)) * 100;
Console.WriteLine("-(DoWork.percentage)-> "+ percentage);
backgroundWorker.ReportProgress((int)percentage);
}
}
void backgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
openingProgressBar.Value = e.ProgressPercentage;
Console.WriteLine("-(ProgressChanged)->" + openingProgressBar.Value);
}
void backgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
openingProgressBar.Visibility = System.Windows.Visibility.Collapsed;
backgroundWorker.Dispose();
Console.WriteLine("-(RunWorkerComplete)-> Done");
}
Since I'm accessing the tablist in the DoWork-Method I wrap that call in the Dispathcer.Invoke. In this form the code kind of does what I want. It makes the collapsed progressBar visible and updates it every once in a while. Sadly it doesn't update the percentage after every file loaded. From what I can see in the console, the ProgressChanged execution lags behind the DoWork. From my understanding it is called in every iteration of the loop though. And even if it fires the UI doesn't always respond to that.
So my question is: Am I still blocking the UI thread somehow and how could I fix it?

The Problem is that
you are do a coupling between UI and BackgroundWorker
The Solution
return on ReportProgress your FileTab object
void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
int i = 0;
foreach (IndexFile file in indexManager.fileList)
{
i++;
Console.WriteLine("-(DoWork)->" + i);
double percentage = (Convert.ToDouble(i) / Convert.ToDouble(indexManager.fileList.Count)) * 100;
Console.WriteLine("-(DoWork.percentage)-> "+ percentage);
backgroundWorker.ReportProgress((int)percentage,new FileTab(file.filePath));
}
}
then add your FileTab object in your backgroundWorker_ProgressChanged to the tabList

Try to move the reporting progress operation into the dispatcher's operations:
foreach (IndexFile file in indexManager.fileList)
{
this.Dispatcher.Invoke((Action)(() =>
{
tabList.Add(new FileTab(file.filePath));
Console.WriteLine("-(DoWork)->" + i);
double percentage = (Convert.ToDouble(i) / Convert.ToDouble(indexManager.fileList.Count)) * 100;
Console.WriteLine("-(DoWork.percentage)-> "+ percentage);
backgroundWorker.ReportProgress((int)percentage);
}));
i++;
}
It's possible that dispatcher runs in another thread...

Background Worker ReportProgress not firing

I'm setting up a background worker for the first time. It is mostly working as the code runs and my stop/cancel button is working. However, I am also trying to report progress to update a progress bar but I cannot get this to fire at all.
I start the code from a button click which runs this code:
backgroundWorker1.WorkerSupportsCancellation = true;
backgroundWorker1.WorkerReportsProgress = true;
backgroundWorker1.RunWorkerAsync();//this invokes the DoWork event
My Do_Work method:
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
BackgroundWorker worker = sender as BackgroundWorker;
int j = 0;// Count cumulative imported files
int countDupFiles = 0;// Count number of previously imported csv files
int countImportedFiles = 0;// Count imported files
foreach (string folderPath in csvDirList)
{
string[] csvFileNames = Directory.GetFiles(#folderPath, "*.csv");
frmImportCsvData.replaceAll(csvFileNames, folderPath + "\\", "");
for (int i = 0; i < csvFileNames.Length; i++, j++)
{
string csvFilePath = folderPath + "\\" + csvFileNames[i];
if ((worker.CancellationPending == true))
{
e.Cancel = true;
break;
}
else
{
if (dataLayer.ImportCsvDataBkgrnd(this, csvFilePath, compIdValue, csvFileCount, i))//new method processes subdirectories if tick box selected
{
countImportedFiles = countImportedFiles + 1;
}
else
{
countDupFiles = countDupFiles + 1;
}
System.Threading.Thread.Sleep(500);
}
worker.ReportProgress(j);//tried using worker and backgroundWorker1 but neither works
backgroundWorker1.ReportProgress(j);
//string proj = j.ToString();
//MessageBox.Show(proj);//Displays incrementing j as expected when not commented out
}
}
if (countImportedFiles > 0)
MessageBox.Show(countImportedFiles + " files were imported.");
if (countDupFiles > 0)
MessageBox.Show(countDupFiles + " files were not imported. Matches all ready in Database.");
}
Trying to fire either of these ProgressChanged events:
private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
string tbProgress = (e.ProgressPercentage.ToString() + "%");
MessageBox.Show(tbProgress + "backgroundWorker1");
importProgressBar(e.ProgressPercentage);
}
private void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
string tbProgress = (e.ProgressPercentage.ToString() + "%");
MessageBox.Show(tbProgress + "worker");
importProgressBar(e.ProgressPercentage);
}
Finally, I want the ProgressChanged event to trigger this method to update my progress bar:
public void importProgressBar(int i)
{
progressTableLayoutPanel.Visible = true;//display progress bar
int percProgress = 100 * (i + 1) / csvFileCount;
if (percProgress <= 99)// Required to prevent values above 100 that crash the code
progressBar.Value = percProgress + 1;//hack that makes the progress bar update when progress value decreases
progressBar.Value = percProgress;
percProgressLabel.Text = percProgress.ToString();
progressTableLayoutPanel.Update();//Required to display all progress bar table contents
//Thread.Sleep(200);
if (percProgress >= 100)
{
Thread.Sleep(200);
progressTableLayoutPanel.Visible = false;
}
}
The cancel button code, which works, looks like this:
private void stopImportButton_Click(object sender, EventArgs e)
{
backgroundWorker1.CancelAsync();
}
The messageboxes in my ProgressChanged events never show up and my progress bar is never set to visible. Any ideas what the problem could be?

Check this example:
BackgroundWorker bgw = new BackgroundWorker();
public Form1()
{
InitializeComponent();
label1.Text = "";
label2.Text = "";
}
private void button1_Click_1(object sender, EventArgs e)
{
if (bgw == null)
{
bgw = new BackgroundWorker();
bgw.DoWork += new DoWorkEventHandler(bgw_DoWork);
bgw.ProgressChanged += new ProgressChangedEventHandler(bgw_ProgressChanged);
bgw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bgw_RunWorkerCompleted);
}
bgw.WorkerReportsProgress = true;
bgw.WorkerSupportsCancellation = true;
bgw.RunWorkerAsync();
}
void bgw_DoWork(object sender, DoWorkEventArgs e)
{
int total = 57; //some number (this is your variable to change)!!
for (int i = 0; i <= total; i++) //some number (total)
{
System.Threading.Thread.Sleep(100);
int percents = (i * 100) / total;
bgw.ReportProgress(percents, i);
//2 arguments:
//1. procenteges (from 0 t0 100) - i do a calcumation
//2. some current value!
}
}
void bgw_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
progressBar1.Value = e.ProgressPercentage;
label1.Text = String.Format("Progress: {0} %", e.ProgressPercentage);
label2.Text = String.Format("Total items transfered: {0}", e.UserState);
}
void bgw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
//do the code when bgv completes its work
}
}
Maybe this helps you with your problem...
And try to put the progress to visible just after you call the background.doWork in the button click event.

Using a Progress bar on Form Load

I am trying to Design a WinForms control in C# which will get some data from a database while it's loading.
I want to use a progress bar to show the progress.
I tried this code (and also many others):
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
this.Show();
progressBar1.Value = 10;
int n;
n = 50;//number of records in DB ,
double progress = 0;
double progstep = 25 / n;
for (int i = 1; i <= n; i++)
{
//getting
if (progress <= 100)
progressBar1.Value = (int)progress;
}
progressBar1.Value = 35;
n = 100;//number of records in DB for another data reading from DB ,
progress = 35;
progstep = 65 / n;
for (int i = 1; i <= n; i++)
{
//getting data from DB
dataGridView1.Rows.Add(....);
//Adding that data to a datagrid -- parametrs removed.
progress += progress;
if (progress <= 100)
progressBar1.Value = (int)progress;
}
}
But, the problem is that the form will wait until data reading progress is completed, and I can see just a full progress bar and all data loaded.
What should I do to fix this?

Since this is winforms, i'd recommend using a BackgroundWorker.
Basic example:
bgWorker.DoWork += new DoWorkEventHandler(bgWorker_DoWork);
bgWorker.ProgressChanged += new DoWorkEventHandler(bgWorker_ProgressChanged);
bgWorker.RunWorkerAsync(//pass in object to process)
Which would then kickoff:
private void bgWorker_DoWork(object sender, DoWorkEventArgs e)
{
//Do all of your work here
bgWorker.ReportProgress(); //percent done calculation
}
Then the Progress changed event would fire to update the UI safely:
private void bgWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
progressBar.Value = e.ProgressPercentage;
}

Add a backgroundWorker1 to your form.
Then add a YourForm_Shown event
private void YourForm_Shown(object sender, EventArgs e)
{
backgroundWorker1.RunWorkerAsync();
}
Add on form's constructor after InitializeComponent()
backgroundWorker1.WorkerReportsProgress = true;
// This event will be raised on the worker thread when the worker starts.
backgroundWorker1.DoWork += new
DoWorkEventHandler(backgroundWorker1_DoWork);
// This event will be raised when we call ReportProgress.
backgroundWorker1.ProgressChanged += new
ProgressChangedEventHandler(backgroundWorker1_ProgressChanged);
And last add the voids of backgroundWorker1:
void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
// The progress percentage is a property of e
progressBar1.Value = e.ProgressPercentage;
}
And:
void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
for (int i = 1; i <= n; i++)
{
//getting data from DB.
dataGridView1.Rows.Add(....);
//Adding that data to a datagrid -- parametrs removed.
backgroundWorker1.ReportProgress(i);
// Simulate long task
}
}

This is simple mockup to show you how to work with background worker:
First in your OnLoad create background worker and attach 2 events to it:
var bw = new BackgroundWorker();
bw.RunWorkerCompleted +=
new RunWorkerCompletedEventHandler(WorkCompleted);
bw.DoWork += new DoWorkEventHandler(DoWork);
bw.RunWorkerAsync(data); // Assume data is list of numbers.
private void WorkCompleted(object sender, RunWorkerCompletedEventArgs e)
// After work completed remove event handlers and dispose.
{
var bw = (BackgroundWorker)sender;
bw.RunWorkerCompleted -= WorkCompleted;
bw.DoWork -= DoWork; bw.Dispose();
}
private void DoWork(object sender, DoWorkEventArgs e)
{
var data = (List<int>)e.Argument;
foreach (var number in data)
{
if (progressBar1.InvokeRequired)
{
progressBar1.Invoke((MethodInvoker)delegate
{ this.ProcessNumber(number); });
}
else
{
ProcessNumber(number);
}
}
}
private void ProcessNumber(int i)
{
progressBar1.PerformStep();
//do something with i
}

Take a look at BackgroundWorker control. During form load invoke;
backgroundWorker.RunWorkerAsync();
and override event DoWork to do the dirty work (load data from database) and ProgressChanged to update progress bar. In the event body (lets say the event signature will be something like this):
private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e) {
var worker = (BackgroundWorker)sender;
// time consuming operation
worker.ReportProgress(10, null);
// ... another stuff
}
private void backgroundWorker_ProgressChanged(object sender,
ProgressChangedEventArgs e)
{
progressBar.Value = e.ProgressPercentage;
}