creating a child form in backgroundWorker

[winsonlee]

private void cmdSales_Click(object sender, EventArgs e)
        {
            backgroundWorker1.RunWorkerAsync();
            timer2.Start();
        }
        private void timer2_Tick(object sender, EventArgs e)
        {

            TimeSpan ts = DateTime.Now.Subtract(startDate);

            string sTime ="  ..." + ts.Minutes.ToString("00") +

               ":" + ts.Seconds.ToString("00") +

               ":" + ts.Milliseconds.ToString("000");

            toolStripStatusLabelTime.Text = sTime;

            if (toolStripProgressBar1.Value ==

                toolStripProgressBar1.Maximum)

            {

                toolStripProgressBar1.Value = 0;

            }

            toolStripProgressBar1.PerformStep();

        
        }
        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            toolStripStatusLabel1.Text = "Loading ... " +

                 "Thanks for your patience";

            frmSales objfrmSChild = frmSales.GetChildInstance();
[B]            objfrmSChild.MdiParent = this;
[/B]            objfrmSChild.Show();
            objfrmSChild.BringToFront();

        }
        private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            toolStripProgressBar1.Value = 100;


            toolStripStatusLabel1.Text = "";

            toolStripProgressBar1.Value = 0;

            timer2.Stop();

            toolStripStatusLabelTime.Text = "";
        }

Progress bar is on the MDI parent form and i would like the progress bar to run after clicking on the button and when the child is loaded the progress bar will stop.

somehow i face problem when comes to "objfrmSChild.MdiParent = this;". Error msg : "Cross-thread operation not valid: Control 'frmContainer' accessed from a thread other than the thread it was created on."

How can i prevent this from happening ?

[serkan sendur]

beginInvoke:
http://progtutorials.tripod.com/C_Sharp.htm#_Toc65227885
http://www.codeproject.com/KB/cs/begininvoke.aspx

[Diamonddrake]

if you pass the instance of the main form to the background worker then cast it to a form, you can then easily pass that instance to the new form. Simple stuffs, Background workers take an object as a argument in the doworkeventargs, just pass it in, then pull it back out.

no need for anything complicated here.

[mlady]

is there a pre-visual ??

[Diamonddrake]

when you call the runworker method pass to it the instance you need

backgroundWorker1.RunWorkerAsync(this);

then in the dowork event handler extract that instance to a variable casting it to the type that it is, an instance of a form.

Form formInstance = (Form)e.Argument;

Thin just pass that instance on to your new form

objfrmSChild.MdiParent = formInstance;

easy as pie :)

happy coding

[amontefusco]

Diamonddrake,

Im newbie in C#, do u can explain again(detailed) or have an example.

PS: My english is very poor...

[Diamonddrake]

Im not sure how much clearer i could be, so I am just going to repost your code, with the modifications that fixes the issue.

private void cmdSales_Click(object sender, EventArgs e)
        {
           [B] backgroundWorker1.RunWorkerAsync(this);[/B]
            timer2.Start();
        }
        private void timer2_Tick(object sender, EventArgs e)
        {

            TimeSpan ts = DateTime.Now.Subtract(startDate);

            string sTime ="  ..." + ts.Minutes.ToString("00") +

               ":" + ts.Seconds.ToString("00") +

               ":" + ts.Milliseconds.ToString("000");

            toolStripStatusLabelTime.Text = sTime;

            if (toolStripProgressBar1.Value ==

                toolStripProgressBar1.Maximum)

            {

                toolStripProgressBar1.Value = 0;

            }

            toolStripProgressBar1.PerformStep();

        
        }
        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {

     //get instance of main form from eventargs
     [B]Form formInstance = (Form)e.Argument;[/B]
            
toolStripStatusLabel1.Text = "Loading ... " +

                 "Thanks for your patience";

            frmSales objfrmSChild = frmSales.GetChildInstance();
            //set mdiparent to instance passed to dowork event
           [B]objfrmSChild.MdiParent = formInstance;[/B] 
            objfrmSChild.Show();
            objfrmSChild.BringToFront();

        }
        private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            toolStripProgressBar1.Value = 100;


            toolStripStatusLabel1.Text = "";

            toolStripProgressBar1.Value = 0;

            timer2.Stop();

            toolStripStatusLabelTime.Text = "";
        }

Happy Coding