[Chronicade]

Do not know what I did to cause the problem, but now I get this problem on this line of code. Maybe one of the settings to the datagridview3 that I changed caused it? Completely baffled. A button triggers a timer, which then ticks to start the backgroundworker. Inside that bgw is this code, I have not touched anything in the code since it last worked, just modified a few datagridview options and made a few other datagridviews.

 if (loopednowupdate == "1")
                    {
                        string[] rowzx = new string[] { UrlDecode(Charnamex), Levelsx, Skillsx, HGsx, Favorsx, Incomesx, tb36, BotStuff, "", "" };
                        dataGridView3.Rows[CurrentBot].SetValues(rowzx);
                    }
                    else
                    {
                        string[] rowz = new string[] { UrlDecode(Charnamex), Levelsx, Skillsx, HGsx, Favorsx, Incomesx, tb36, BotStuff, "", "" };
                        dataGridView3.Rows.Add(rowz);//<------------THIS LINE!
                    }

This post has been edited by Chronicade: 28 October 2010 - 09:01 PM

[mavarazo]

Mostly the Exception is because of an access of an object which is outside of the DoWork.
When you want to add a Row to the GridView use Invoke: Control.Invoke Method (Delegate)

[AdamSpeight2008]

A background worker is on a different thread to the form.

[eclipsed4utoo]

You can't access a UI Control from a background thread.

[Chronicade]

Yeah I know all of that, but I would like to know what would cause this to error when it has been working for a while. Small things changed too.

[eclipsed4utoo]

Maybe it wasn't being run in the DoWork event of the BackgroundWorker? Maybe it was in the RunWorkerCompleted Event and was moved into the DoWork event? All I know is, that code will fail everytime.

[ragingben]

Well as the other guys have said it is because you are changing an object belonging to the UI thread on a background thread. On the line

dataGridView3.Rows.Add(rowz);

you are adding a row to the data grid. This is changing the object. Maybe you didn't used to do it this way, but this line will always have caused an error from a background thread, because you are modifying a UI object from a thread other than that which it was created on. You can use the Invoke() method of a control to update it from a different thread...

// use .Invoke() to invoke an update to a UI object belonging to a different thread. Add this where you need it in the DoWork() code
this.dataGridView3.Invoke(new UIUpdaterDelegate(() =>
{
    // add
    this.dataGridView3.Rows.Add(rowz);

}));

// I used this delegate to update the code... add it to your namespace
delegate void UIUpdaterDelegate();

Hope that helps

[Chronicade]

Right as soon as I finish modifying some google code on Invoking. I get a new email and you post a copy. Awesome Ill give it a shot. Thanks for all the help, but seriously I have not touched the backgroundworker at all, only things on the main thread. My other backgroundworkers can still actively modify the main thread. O_O

[JackOfAllTrades]

We also have this tutorial on the subject.

[mavarazo]

Perhaps it was the first time, that loopednowupdate was not 1

[Chronicade]

Awesome, the code work, mucho kudos. So, a lot of my code is done in backgroundworkers and numerous parts involve datagridviews. My question is for some reason without me having to invoke anything it works, but a little weird. Sometimes it does what it is supposed to with a few problems, then other times it seems to work fine. Would this be a result to me having a buggy call from a backgroundworker that is accessing the main thread?

This post has been edited by Chronicade: 29 October 2010 - 10:57 PM

[elbielefeld]

Maybe you have set the CheckForIllegalCrossThreadCalls property of the form to false.

[Chronicade]

Nope