Updating label with data from thread

Anele Ngqandu

I am trying to update a label in windows forms. The action is happening in a separate class but while the action is happening on a separate class. The label should be updated, but things seem to be not working. Kindly assist

Below is the Back code of the form ProcessingUI

public partial class ProcessingUI : Form
{
private void start_Click(object sender, EventArgs e)
{
StartProcessingTask();
}
private void StartProcessingTask()
{
if (_isRunning)
return;
_isRunning = true;
_taskToken = new CancellationTokenSource();
Task.Factory.StartNew(() =>
{
while (_isRunning)
{
var data = _processing.Processdata(lblCounter, _taskToken);
if (data.Success)
_isRunning = false;
if (_taskToken.IsCancellationRequested)
return;
}
});
}
public delegate void SetStatusCallback(string message);
public void UpdateStatus(string message)
{
if (this.lblCounter.InvokeRequired)
{
this.Invoke(new SetStatusCallback(UpdateStatus),
message);
}
else
this.lblCounter.Text = message;
}
}

Then here is a separate class that has the action, basically its just updating. Now on update I just want to pass the record that is being updated. So i call the Method from the form and use it in this class.

public class Processing
{
public Results Processdata(CancellationTokenSource taskToken)
{
foreach (var record in dataCases)
{
//Doing other things here like updating
new ProcessingUI().UpdateStatus(record.RequestReference);//This is the method I am calling from the form.
}
}
}

6 Replies

Know the answer? Post it — somebody with the same question will find it here.

Hemant Jindal8y ago
Accepted answer
Hi Anele

Please call method backgroundWorker1.ReportProgress(); from within the backgroundWorker1_DoWork. Actually ReportProgress triggers event

thanks
Hemant Jindal
0
Anele Ngqandu8y ago
Hi Hemant

I I was just busy with thit aproach now. Then i have a berakpoint in ProgressChanged(object sender, ProgressChangedEventArgs e) but its not being hit.
//Start button
private void start_Click(object sender, EventArgs e)
        {
            if (backgroundWorker1.IsBusy != true)
            {
                //Start the asynchronous operation.
                backgroundWorker1 = new System.ComponentModel.BackgroundWorker
                {
                    WorkerReportsProgress = true,
                    WorkerSupportsCancellation = true
                };
                backgroundWorker1.DoWork += backgroundWorker1_DoWork;
                backgroundWorker1.ProgressChanged += backgroundWorker1_ProgressChanged;
                backgroundWorker1.RunWorkerCompleted += backgroundWorker1_RunWorkerCompleted;

                // Start background worker
                backgroundWorker1.RunWorkerAsync();
            }
        }

//then the Progresscchangeevent
   private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {

         //breakpont needs to stop but it doesnt

        }
0
Hemant Jindal8y ago
Hello Anele Ngqandu;

You can also use BackgroundWorker. I have created a sample application for your reference. Hope this help you

public class ProcessManager
{
readonly BackgroundWorker worker = new BackgroundWorker();

public void StartProcess()
{
worker.DoWork += Worker_DoWork;
worker.ProgressChanged += Worker_ProgressChanged;
worker.RunWorkerCompleted += Worker_RunWorkerCompleted;
worker.RunWorkerAsync();

}

private void Worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{

}

private void Worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
//update your label here
}

private void Worker_DoWork(object sender, DoWorkEventArgs e)
{
for (int i = 0; i < 1000; i++)
{
//Add your code to process
Console.WriteLine("In progress");
Thread.Sleep(1000);
int percentage = (i + 1) * 100 / 1000;
worker.ReportProgress(1, null);
}
}
}

static void Main(string[] args)
{
ProcessManager processSomeThing = new ProcessManager();
processSomeThing.StartProcess();
Console.ReadLine();
}

Thanks
Hemant Jindal
0
Prakash Chasiya8y ago
Hi Anele;

You need to send simple demo of your issue, So I can check. Or just understand the link article I have sent across. It will surely help you.

Thanks
Prakash
0
Anele Ngqandu8y ago
Hi Prakash

Not sure if this will help.
  public class Processing
    {
public Results Processdata(Label lblCounter, CancellationTokenSource taskToken)
        {

            try
            {
                using (var db = new ManualWithDrawDataContext())
                {
                    var dataCases = fetchUnprocessedData(db);
                    if (!dataLCases.Any())
                    {
                        return new Results
                        {
                            Status = "Success",
                            DescripText = "No data to be processed",
                            Success = false
                        };
                    }
                    foreach (var record in dataCases)
                    {
                        try
                        {

//initialy the label was updated here but it needs to move to back code of the form
                            lblCounter.Invoke((Action)delegate
                            {

                                lblCounter.Text = @"Processing..." + record.RequestReference;
                            });


                new ProcessingUI().UpdateStatus(record.RequestReference);

                            //PushToService(record);
                            record.ProcessedDate = DateTime.Now;
                            record.ProcessStatusId = (int)ProcessStatus.Processed;
                            db.SubmitChanges();
                            if (taskToken.IsCancellationRequested)
                                break;

                        }
                        catch (Exception ex)
                        {

                            record.ProcessStatusId = (int)ProcessStatus.Fail;
                            record.ErrorExceptions = ex.StackTrace;
                        }

                    }
                }
            }
            catch (Exception ex)
            {
                return new Results
                {
                    Status = "Fail",
                    DescripText = ex.Message,
                    Success = false
                };
            }
            return new Results { Status = "Success", Success = true };
        }
}
0
Prakash Chasiya8y ago
Hello Anele Ngqandu;

Please attached the exact scenario with code. Other than this, If you are using multi threaded operations in windows forms than you can use asyn operation for updating the dashboard of your app.

Please refer the link : https://www.c-sharpcorner.com/article/multi-threading-with-windows-forms/

I hope it will be helpful to solve your issue.

Thanks
Prakash
0