Get current value in a for loop

Question

I have a few nested for loops, and I was wondering if I could get the data while it's processing it, So I can show it on the screen as a loading bar.

Here's an example:

double currentData;
double endData = 50 * 50 * 50;

for(int i = 0; i < 50; i++)
{
  for(int e = 0; e < 50; e++)
  {
    for(int a = 0; a < 50; a++)
    {
      currentData = a * e * i;
    }
  }  
}

label1.Text = "Loading: " + Convert.ToString(100/endData * currentData) + "%.";

If I'm not wrong, for loops make the program "freeze" until its done, so that's probably why this code won't work. Any suggestions?

Thanks

Answer 1

Well if you are using WinForms you can use background worker to execute the loop:

//declare in form
var bw = new BackgroundWorker();

//in constructor or load write this
bw.WorkerReportsProgress = true;
bw.DoWork += new DoWorkEventHandler(bwDoWork);
bw.ProgressChanged += new ProgressChangedEventHandler(bwProgressChanged);
bw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bwCompleted);

private void bwDoWork(object sender, DoWorkEventArgs e)
{
    var worker = sender as BackgroundWorker;
    for(int i = 0; i < 50; i++)
    {
        for(int e = 0; e < 50; e++)
        {
            for(int a : 0; a < 50; a++)
            {
                worker.ReportProgress(a * e * i);
            }
        }  
    }
}

private void bwProgressChanged(object sender, ProgressChangedEventArgs e)
{
    var pp=e.ProgressPercentage; //now set the progress here
}

private void bwCompleted(object sender, RunWorkerCompletedEventArgs e)
{
    //set the progress to 100% etc.
}

Then as pointed by @paqogomez you need to call the worker to run, may be on some button click etc.

//may be in private void button_click(object sender, EventArgs e)
if (!bw.IsBusy)
{
    bw.RunWorkerAsync();
}

You can get more info on BackgroundWorker here and here.