BackgroundWorker_ProgressChanged in a foreach?

Question

Hi all,

I have a backgroundWorker that contains a foreach and essentially goes through a dataSet and loads an image for each row in the set. This appears to be working, but I don't honestly know because when I call backgroundWorker.ReportProgress(100) it doesn't appear to be firing the progress changed until AFTER it goes through the last foreach. I have the ReportProgress call in the foreach by the way, at the end and when setting a breakpoint it does hit that when I would expect it to.

I guess my question at this point so that I can at least test out all of my other code is how can I fire the progressChanged at the completion of each item in my foreach?

Below you can see the code that I am using.

I am instantiating the button (Though this may not be correct)

ButtonItem button = new ButtonItem();

BackgroundWorker_DoWork

            foreach (DataRow dr in PicDataSet.Tables["Pictures"].Rows)
            {
                string AttachmentNameString = dr["AttachmentName"].ToString();

                //ButtonItem button = new ButtonItem();
                button.Size = new System.Drawing.Size(125, 30);
                button.Tag = dr["ID"].ToString();
                button.Text = dr["AttachmentTitle"].ToString();
                button.ImagePaddingHorizontal = 5;
                button.ImagePaddingVertical = 5;

                button.ImageFixedSize = new System.Drawing.Size(90, 90);
                button.ImagePosition = eImagePosition.Top;

                ImagePathString = MappedDriveString + @"\Pictures\Jobs\Thumbnails\" + AttachmentNameString;

                button.Click += this.PictureButton_Click;

                //Populate Image
                try
                {
                    using (FileStream fs = new FileStream(ImagePathString, FileMode.Open))
                    {
                        int len = (int)fs.Length;
                        byte[] buf = new byte[len];
                        fs.Read(buf, 0, len);
                        using (MemoryStream ms = new MemoryStream(buf))
                            img = new Bitmap(ms);

                        button.Image = img;

                        fs.Dispose();

                        PicturesBW.ReportProgress(100);
                    }

                }
                catch
                {
                    button.Image = ProjectDesk1.Properties.Resources.RedX_128;
                }
            }

BackgroundWorker_ProgressChanged (I tried using sender but got a target of an invocation error).

            if (e.ProgressPercentage == 100)
            {
                //ButtonItem button = sender as ButtonItem;

                AttachmentsItemPanel.BeginUpdate();

                PicturesContainer.SubItems.Add(button);

                AttachmentsItemPanel.EndUpdate();
            }

BackgroundWorker_Completed

//Still working here.

So, I really appreciate the help anyone can give me here. I think my first problem is the foreach issue but if anyone has any suggestions or ideas for any of this I will certainly appreciate any and all input. I do mark answers as well. :)

Thanks

Answer 1

Hello:

You can try this:

 

private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{

//In your for loop. Set the max to some high number. I set it to 100.

    for (int i = 0; i <= max; i++)
            {
                // Report progress to 'UI' thread
                backgroundWorker.ReportProgress(i); // This fires backgroundWorker_ProgressChanged event handler.
                // Simulate long task
                System.Threading.Thread.Sleep(100); // Make the main thread sleep so that when your time taking is running the UI won't hang.
  
      }

        private void backgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {

             // use this e.ProgressPercentage value the way you want. In this it applies this value to the progressbar control.

            progressBar.Value = e.ProgressPercentage;
        }

        private void backgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {

                 Display any ending/succesful messages here. This case it updates the label. "Status" is a label control.

            status.Text = "Uninstallation Complete!" + "\r\n";
        }

Answer 2

Hi C_Newbie01,

I provisionally marked vasumadhav's reply as answer.

Please  feel  free to unmark it if you think the information does not help.

Regards ,

---

Lisa Zhu [MSFT]
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