Question

This is the code of the DoWork event the ProgressChanged event and the RunWorkerCompleted event. The problem is that the progressBar is getting to 100% much faster before the function process operation is end. So when the progressBar is up to 100% I’m getting error exception since the progressBar can’t be 101%

I need somehow to make that the progressBar will get progress according to the function process / progress. I guess that something is wrong with my calculation in the DoWork event.

In the Form1 top I added:

Int i;

In the constructor I did:

i = 0;

backgroundWorker1.WorkerSupportsCancellation = true;
backgroundWorker1.WorkerReportsProgress = true;
backgroundWorker1.RunWorkerAsync();

And this is the events of the Backgroundworker:

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
   BackgroundWorker worker = sender as BackgroundWorker;
   //int currentLength;
   //int currentIndex;
   //int lastIndex = 0;
   string startTag = "T256=\"";
   string endTag = "\"";
   int startTagWidth = startTag.Length;
   //int endTagWidth = endTag.Length;
   int index = 0;

   h = new StreamReader(@"d:\DeponiaSplit\testingdeponias_Translated.txt");

   while ((line = h.ReadLine()) != null)
   {
      if (index > f.LastIndexOf(startTag))
      {
         break;
      }

      int startTagIndex = f.IndexOf(startTag, index);
      int stringIndex = startTagIndex + startTagWidth;
      index = stringIndex;
      int endTagIndex = f.IndexOf(endTag, index);
      int stringLength = endTagIndex - stringIndex;

      if (stringLength != 0)
      {
         string test = f.Substring(stringIndex, stringLength);
         f = f.Substring(0, stringIndex) + line + f.Substring(stringIndex + stringLength);

         if (listBox1.InvokeRequired)
         {
            textBox1.Invoke(new MethodInvoker(delegate { textBox1.Text = line; }));
         }

         i = i + 1;
         System.Threading.Thread.Sleep(500);
         worker.ReportProgress((i * 1));
      }
   }

   h.Close();

   StreamWriter w = new StreamWriter(@"D:\New folder (24)\000004aa.xml");
   w.AutoFlush = true;
   w.Write(f);
   w.Close();
}

private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
    //this.progressBar1.Text = (e.ProgressPercentage.ToString() + "%");
    progressBar1.Value = e.ProgressPercentage;
}

private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
   if ((e.Cancelled == true))
   {
      this.progressBar1.Text = "Canceled!";
   }
   else if (!(e.Error == null))
   {
      this.progressBar1.Text = ("Error: " + e.Error.Message);
   } 
   else
   {
       this.progressBar1.Text = "Done!";
   }
}

Why doesn’t it work correctly?

Working using FileStream

Now I wanted to add to the progressBar a label which will show % and the label will move according to the progressBar I don’t want to disable the progressBar green color progress just to add % and show the numbers in percentages.

So in the ProgressChanged event I did :

private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
    progressBar1.Value = e.ProgressPercentage;
    label3.Text = (e.ProgressPercentage.ToString() + "%");
} 

But it doesn’t work – the label13 doesn’t move only the % changed to 1. I want to see something like 1%…2%…3%… and so on. How can I do it?

Answer 1

Why don’t you use File.ReadAllLines, it returns an array of strings. You could report your progress as the percentage of the line you are processing to the total number of lines:

string[] lines = File.ReadAllLines(@"d:\DeponiaSplit\testingdeponias_Translated.txt"); 
// ...
worker.ReportProgress(i * 100 / lines.Length);