Question

I download many urls from the web but I don’t know when all the urls have been finished to download. Meanwhile I wrote something, but it seem too me a trash although it works.

In my code I download all the urls from dtPP dataTable and save them to matUrlFharsing array.

Here is my code:

main()
{
    Parallel.For(0, dtPP.Rows.Count, i =>
    {
         string f = "";
         WebClient client = new WebClient();
         client.DownloadDataCompleted += new DownloadDataCompletedEventHandler(client_DownloadDataCompleted);
         lock (dtPP.Rows[i])
         {
              f = dtPP.Rows[i]["pp_url"].ToString();
         }
         client.DownloadDataAsync(new Uri(f), i);
    });
    while (end)
    {
    }
    DoSomething();
 }


void client_DownloadDataCompleted(object sender, DownloadDataCompletedEventArgs e)
        {
            int h = (int)e.UserState;
            page = (int)e.UserState;
            myString = enc.GetString(e.Result);

            lock (matUrlFharsing[h])
            {
                lock (dtPP.Rows[h])
                {
                    //save in mat
                    matUrlFharsing[h] = Pharsing.CreateCorrectHtmlDoc(myString);
                }
            }

            lock (myLocker)
            {
                ezer = false;
                for (int j = 0; j < matUrlFharsing.Length && !ezer; j++)
                {
                    if (matUrlFharsing[j] == "")
                        ezer = true;
                }
                end = ezer;
            }
        }

What can I do to improve or change it?

Answer 1

Small improvement:

Use AutoResetEvent instead of bool for End.

AutoResetEvent autoResetEvent;

main()
{
    autoResetEvent = new AutoResetEvent(false);
    Parallel.For(0, dtPP.Rows.Count, i =>
    {
        // your code
    });
    autoResetEvent.WaitOne();
    DoSomething();
 }

void client_DownloadDataCompleted(object sender, DownloadDataCompletedEventArgs e)
{
   ...
   if(ezer)
   {
       autoResetEvent.Set();
   }

}