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Cancel button wait for BackgroundWorker to finish (ASP.NET C#)

I'm working with C# ASP.NET Web Application. There is a problem that is difficult to track in the code.
Let's say I have two buttons: Upload (which uploads some data from DataTable to Database) and Cancel (which cancels the uploading process). The problem is that uploading process runs in the BackgroundWorker. When user clicks Upload and uploading starts and then he clicks Cancel the Cancel_Button_Click event does not fire until BackgroundWorker is uploading data.
I have code like this:
protected void Page_Load(object sender, EventArgs e)
{
backgroundWorker1.ProgressChanged += new System.ComponentModel.ProgressChangedEventHandler(backgroundWorker1_ProgressChanged);
backgroundWorker1.RunWorkerCompleted += new System.ComponentModel.RunWorkerCompletedEventHandler(backgroundWorker_RunWorkerCompleted);
}
protected void Upload_Button_Click(object sender, EventArgs e)
{ backgroundWorker1.RunWorkerAsync(); }
protected void Cancel_Button_Click(object sender, EventArgs e)
{ backgroundWorker1.CancelAsync(); }
private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{ };
So what really happens is when you click Upload and Cancel is method private void backgroundWorker1_ProgressChanged runs many times (one time for every row of data, I suppose) and ONLY THEN method Cancel_Button_Click runs.
What to do, if I want to stop data uploading right after Cancel button is clicked?
Thaaaanks! :)
P.S. I tried searching on the net but I don't even know how to describe my problem in one sentence.

Timer to refresh charts in c#

I have created a chart which receives its data from a SQL Server database. Whenever I save new data into the database, all the reports get updated, but the chart does not update until I exit the application and log in again. I decided to use Timer in C# to automatically refresh the chart every 5 seconds.
//this is to invoke the timer as soon as the application launches.
public MDIParent2()
{
InitializeComponent();
myTimer.Enabled = true;
myTimer.Start();
}
//this is my timer event
private void myTimer_Tick(object sender, EventArgs e)
{
this.Refresh();
MessageBox.Show("Refreshed!");//this was added to determine if the timer is working
}
//this lets me stop the timer
private void button1_Click(object sender, EventArgs e)
{
myTimer.Stop();
}
//this lets me resume the timer
private void button2_Click(object sender, EventArgs e)
{
myTimer.Start();
}
I get the message "Refreshed!" every 5 seconds, but chart is still not refreshed. Can someone please assist?

replace this.refresh() with [Chart Object].refresh()

StatusLabel - how to reset, or allow status text to time out or fade away

I have a tabbed form with a StatusStrip at the bottom, which includes a StatusLabel. I want to use this status label for various actions ("1 record updated" etc). It is simple enough to create specific events to set the label's text property.
But how best to reset the status to blank? The user could perform any number of other operations where the status is no longer meaningful (going to another tab, clicking other buttons etc.).
It is not feasible to create all the possible events to reset the status message. Is there a way to incorporate some type of timer so that the message fades out after several seconds? Has anyone else found a good solution for this?

Is it truly important to clear the status though? There are plenty of products which will keep their status label unchanged until the next status event occurs. Visual Studio is a good example of this. It may be worth simplifying your scenario and taking this approach.
If you do want to clear the status after an event I think the most maintainable way to do this is with a Timer. Essentially clear after a few seconds when the status is set
Timer m_timer;
void SetStatus(string text) {
m_statusLabel.Text = text;
m_timer.Reset();
}
void OnTimerTick(object sender, EventArgs e) {
m_statusLabel.Text = "";
m_timer.Stop();
}

Yes a timer would work for this to clear it. Here is an example of one I've knocked together.
public partial class Form1 : Form
{
private System.Timers.Timer _systemTimer = null;
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
_systemTimer = new System.Timers.Timer(500);
_systemTimer.Elapsed += _systemTimer_Elapsed;
}
void _systemTimer_Elapsed(object sender, ElapsedEventArgs e)
{
toolStripStatusLabel1.Text = string.Empty;
_systemTimer.Stop(); // stop it if you don't want it repeating
}
private void button1_Click(object sender, EventArgs e)
{
toolStripStatusLabel1.Text = "random text just as an example";
}
private void button2_Click(object sender, EventArgs e)
{
_systemTimer.Start();
}
}
Assume button1 is your action to update the status, and button2 is just a random way to start the timer (this can be however you want to start it, I've only used another button click as an example). After the set amount of time passes the status label will be cleared.

.NET Timer Control

I have a windows app which is just a form with a timer control on. I've managed to track this down to the following situation:
private void timer1_Tick(object sender, EventArgs e)
{
MessageBox.Show("Test");
timer1.Enabled = false;
}
Will print Test again and again until I stop the program. However:
private void timer1_Tick(object sender, EventArgs e)
{
//MessageBox.Show("Test");
textBox1.Text += "t";
timer1.Enabled = false;
}
Just adds a single "t" to the textbox.
Can anyone tell me why MessageBox.Show is causing the function to return before the timer is disabled?

The call to MessageBox.Show blocks execution of timer1_Tick until you close the messsagebox, so the call to set timer1.Enabled = false; doesn't occur until after that. Because of this, the timer is still running and thus timer_Tick` still keeps getting called, every time the timer fires, until you hit OK on one of the message boxes.
What you need, if you want displaying the messagebox to stop the timer from firing again, is:
private void timer1_Tick(object sender, EventArgs e)
{
timer1.Enabled = false;
MessageBox.Show("Test");
}

You disable the timer after the user clicked the messagebox away.
MessageBox.Show shows a modal dialog. It will return (to the caller method) after the user responded to the messagebox. If you disable the timer first, the event will not be triggered again, and the user will have enough time to react.
Try this:
timer1.Enabled = false;
MessageBox.Show("Test");

Are you clicking OK on test, each timer click? If the message boxes keep stacking up one on top of the other, it's because MessageBox.Show doesn't return until you close the messagebox. In the meantime a message pump will continue to run, and process your timer messages.

ShowDialog, PropertyGrid and Timer problem

I have a strange bug, please, let me know if you have any clues about the reason.
I have a Timer (System.Windows.Forms.Timer) on my main form, which fires some updates, which also eventually update the main form UI. Then I have an editor, which is opened from the main form using the ShowDialog() method. On this editor I have a PropertyGrid (System.Windows.Forms.PropertyGrid).
I am unable to reproduce it everytime, but pretty often, when I use dropdowns on that property grid in editor it gets stuck, that is OK/Cancel buttons don't close the form, property grid becomes not usable, Close button in the form header doesn't work.
There are no exceptions in the background, and if I break the process I see that the app is doing some calculations related to the updates I mentioned in the beginning.
What can you recommend? Any ideas are welcome.

What's happening is that the thread timer's Tick method doesn't execute on a different thread, so it's locking everything else until it's done. I made a test winforms app that had a timer and 2 buttons on it whose events did this:
private void timer1_Tick(object sender, EventArgs e)
{
Thread.Sleep(6000);
}
private void button1_Click(object sender, EventArgs e)
{
timer1.Start();
}
private void button2_Click(object sender, EventArgs e)
{
frmShow show = new frmShow();
show.ShowDialog(); // frmShow just has some controls on it to fiddle with
}
and indeed it blocked as you described. The following solved it:
private void timer1_Tick(object sender, EventArgs e)
{
ThreadPool.QueueUserWorkItem(DoStuff);
}
private void DoStuff(object something)
{
Thread.Sleep(6000);
}