multithreading

multithreading

• THE RAZI

  Russ, it is a lot of code. Specifically, what part do you want
  
  

• vakman

  (sender as BackgroundWorker).ReportProgress(currentLoop);

  So far no luck--the same thing: not updating.
  

  
  
  

• pd_tch

  Well, it is an unexpected solution! Thank you. Maybe it is the way to go. I've already put some code in and it compiled.
  
  

• nino_emcee

  Heres a threaded version:

  using System;

  using System.Collections.Generic;

  using System.ComponentModel;

  using System.Data;

  using System.Drawing;

  using System.Text;

  using System.Windows.Forms;

  using System.IO;

  using System.Net;

  namespace WindowsApplication1

  {

  public partial class Form1 : Form

  {

  public Form1()

  {

  InitializeComponent();

  }

  private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)

  {

  DownloadFile("http://download.freewarefiles.com/files/foobar2000_0.9.4.exe", "C:\\test.exe");

  }

  bool pMaxSet;

  private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)

  {

  if (!pMaxSet)

  {

  pMaxSet = true;

  progressBar1.Maximum = e.ProgressPercentage;

  return;

  }

  progressBar1.Value = e.ProgressPercentage;

  }

  private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)

  {

  MessageBox.Show("Download Complete");

  }

  private void DownloadFile(string sURL, string Filename)

  {

  System.Net.HttpWebRequest URLReq;

  System.Net.HttpWebResponse URLRes;

  System.IO.FileStream FileStreamer;

  byte[] bBuffer = new byte[1024];

  int pMax = 0;

  int pValue = 0;

  int iBytesRead = 0;

  FileStreamer = new FileStream(Filename, System.IO.FileMode.Create);

  URLReq = (HttpWebRequest)System.Net.WebRequest.Create(sURL);

  URLRes = (HttpWebResponse)URLReq.GetResponse();

  using (Stream sChunks = URLReq.GetResponse().GetResponseStream())

  {

  pMax = Convert.ToInt32(URLRes.ContentLength);

  backgroundWorker1.ReportProgress(pMax);

  do

  {

  iBytesRead = sChunks.Read(bBuffer, 0, 1024);

  FileStreamer.Write(bBuffer, 0, iBytesRead);

  if (pValue + iBytesRead <= pMax)

  {

  pValue += iBytesRead;

  backgroundWorker1.ReportProgress(pValue);

  }

  else

  backgroundWorker1.ReportProgress(pMax);

  }

  while (iBytesRead != 0);

  backgroundWorker1.ReportProgress(pMax);

  sChunks.Close();

  FileStreamer.Close();

  }

  }

  private void Form1_Click(object sender, EventArgs e)

  {

  backgroundWorker1.RunWorkerAsync();

  }

  }

  }

  
  
  

• Lehmberg

  I'm by no means an expert, but I feel like I am missing something here. Why not just use:

  (sender as BackgroundWorker).ReportProgress(ii);

  It seems like you are doing extra math and casting that isn't necessary.

  Let me know if that make any difference.

  Thanks,
  Russ

  
  

• RMon

  I just had a similar situation, and I got rid of the timer altogether. Instead I used the backgroundWorker component:

  http://msdn2.microsoft.com/en-us/library/system.componentmodel.backgroundworker.aspx

  Good luck,
  Russ

  
  

• Mark Willer

  Alex,

  Could you post your code

  Thanks,
  Russ

  
  

• Shady9399

  Thank you. This is the routine you may be looking for. I did some minor surgery on it for clarity. Hopefully I did not remove anything essential:)

  public TimeSpan subPushHTTPrequestAll_Click ( BackgroundWorker worker, Object sender, DoWorkEventArgs e )
  {
  string symbol;
  int numberToDownload = this.comboSymbols.Items.Count - 1;
  Class2 class2 = new Class2 ( );
  ThreadStart threadDelegate = new ThreadStart ( Work.DoWork );
  Thread newThread = new Thread ( threadDelegate );
  newThread.Start ( );
  DateTime dateTimeStart = System.DateTime.Now;
  // one way to get all .csv files is:
  // process the list of files found in the directory.
  string thePath = Application.StartupPath;
  string cur_drive = thePath.Substring ( 0, 2 );
  string targetDirectory = cur_drive + @"\VFP_Projects\Data\Stoxx\";
  string[] fileEntries = Directory.GetFiles ( targetDirectory );
  char[] delim = {'\\'};
  string[] namesArr = new string[1];
  
  // second way is to get them from ComboSymbols.DataSource
  
  for ( int ii = 0; ii <= this.comboSymbols.Items.Count - 1; ii++ )
  {
  symbol = ( string )this.comboSymbols.Items[ii];
  symbol = symbol.Trim ( );
  int switched = ( ii + 1 ) % 10;

  float proggr = ii / numberToDownload * 100f;
  int prg = (int) proggr;
  (sender as BackgroundWorker).ReportProgress ( prg );
  Boolean returns = class2.getOneCSVfromYahoo ( symbol );
  if ( returns != true )
  {
  Console.WriteLine ( "COULD NOT REFRESH: ", symbol );
  Console.WriteLine ( symbol );
  }
  else
  {
  // will see if the company name is missing in correlates.dbf
  if ( Globals.flaggedEmpty == true )
  {
  string sql1 = "SELECT * FROM 'correlates.dbf'";
  string inpStr1 = "stoxx";
  DataTable dt1 = Class2.getData ( sql1, class2.getConnStrings ( ref inpStr1 ) );
  foreach ( DataRow row in dt1.Rows )
  {
  if ( (( string )row["named"]).Trim ( ) == "" )
  {
  Console.WriteLine ("empty: {0} ", ( string )row["named"] );
  row["named"] = Globals.named;
  Console.WriteLine ( "changed : {0} ", ( string )row["named"] );
  }
  }
  dt1.AcceptChanges ( );
  }
  }
  } // end of loop for all companies. The company name ends up in Globals.named
  DateTime dateTimeEnd = DateTime.Now;
  TimeSpan span = dateTimeEnd - dateTimeStart;
  Console.WriteLine ( "the time spent : {0}", span );
  return span;
  }
  

  
  
  

• redshock

  private bool DownloadFile(string sURL, ProgressBar pProgress, string Filename)

  {

  System.Net.HttpWebRequest URLReq;

  System.Net.HttpWebResponse URLRes;

  System.IO.FileStream FileStreamer;

  byte[] bBuffer = new byte[1024];

  int iBytesRead = 0;

  try

  {

  FileStreamer = new FileStream(Filename, System.IO.FileMode.Create);

  URLReq = (HttpWebRequest)System.Net.WebRequest.Create(sURL);

  URLRes = (HttpWebResponse)URLReq.GetResponse();

  using (Stream sChunks = URLReq.GetResponse().GetResponseStream())

  {

  pProgress.Maximum = Convert.ToInt32(URLRes.ContentLength);

  do

  {

  iBytesRead = sChunks.Read(bBuffer, 0, 1024);

  FileStreamer.Write(bBuffer, 0, iBytesRead);

  if (pProgress.Value + iBytesRead <= pProgress.Maximum)

  {

  pProgress.Value += iBytesRead;

  }

  else

  pProgress.Value = pProgress.Maximum;

  }

  while (iBytesRead != 0);

  pProgress.Value = pProgress.Maximum;

  sChunks.Close();

  FileStreamer.Close();

  return true;

  }

  }

  catch (Exception ee)

  {

  MessageBox.Show(ee.Message);

  return false;

  }

  }

  
  
  

• Corres

  "I set WorkerProgressBar = true;"

  That should have been: worker.WorkerReportsProgress = true;

  Sorry.

  
  
  

• mark brayton

  It sounds like you aren't updating the progressBar while the second thread is executing.

  I'm not sure what your processing is, but for example if you were using a loop:

  i = 1;
  for (i = 1; i <= 1000; i++)
  {

  //do your work here
  
  currentLoop = i;
  (sender as BackgroundWorker).ReportProgress(currentLoop);
  }

  
  

• cwlaualex

  Hi cab,

  This is cute but does not seem to be a separate thread. Could you comment on the advantage of this code from your point of view

  It seems to me pretty much what I have got or close.

  I wish I could give you a job:)

  Thanks

  
  
  

• aragon

  Basically the section where you are updating the backgroundWorker component.

  It should be working, so I'd like to see what's going on.

  Thanks,
  Russ

  
  

• _hunter

  Russ hi,

  If you have a chance to read this: I got the BacgroundWorker working. It definitely runs and performs as needed with one minor but nasty surprise. It does not handle the progress bar. I mean it showed me the final result only, pretty much as I had before. The progress bar was blank during the procedure (file downloading) and after downloading was finished it went all the way up.

  I set WorkerProgressBar = true; I do not know what else I can do for it to work.

  Any suggestions

  Also it refused to interact with any user-interface controls along the way. This is of course a part of the class description. There is a warning about it. So I have to do some additional coding but since the progress bar does not work, it is unclear if the other controls (label, textBox) will be reactive either.

  Did you get your progress bar working

  In any event I needed multithreading for other things more than for this. From this standpoint I am quite grateful to you for the suggestion.

  Thanks.

  
  
  
• multithreading