Background worker (to prevent freezing) (1 Viewer)

[Dragy]

In a windows forms app I can just use the BackgroundWorker from the Toolbox.. but how to do that with a MediaPortal plugin? I don't want that MP freezes when I retrieve some stuff from the web.
I also like to show a progressbar when it is doing stuff in the background.

How to achieve this?

 

[DJBlu]

In a windows forms app I can just use the BackgroundWorker from the Toolbox.. but how to do that with a MediaPortal plugin? I don't want that MP freezes when I retrieve some stuff from the web.
I also like to show a progressbar when it is doing stuff in the background.

How to achieve this?

VB

Dim MyThread as new threading.thread(Addressof MySub)

Thread.start

Sub MySub

'Insert code here.

End Sub

C#

Thread MyThread = new Thread(addressof MyVoid);
MyThread.Start;

void MyRoutine
{
// Insert Code here
}

 

[Dragy]

Thanks! I will search for mor information about Thread
And sorry I forgot to mention I use C#

 

[SilentException]

I wouldn't use the bare Thread. BackgroundWorker wrapper is easier to use for this purpose.

Decide whether you need progress bar for your purpose, for 99% web operations, using GUIWaitCursor is enough. If you need progress bar, you can use GUIDialogProgress.

 

[Dragy]

Okay thanks

Actually, GUIWaitCursor was the "progressbar" I was thinking of
Now I'm going to read some stuff... Threading in C# - Free E-book

 

[tourettes]

If using a tread remember to add try/catch for errorn handling around the thread method. Otherwise if you manage to create an unhandled exception inside the code whole application will be closed down without a warning.

 

[Dragy]

I have made some progress with it and this is working, but is this the right way to do?
I have some kind of feeling this is not the way to use it.

protected override void OnClicked(int controlId, GUIControl control, MediaPortal.GUI.Library.Action.ActionType actionType)
        {
            if (control == buttonDevices)
            {
                bw_get = new BackgroundWorker();

                GUIWaitCursor.Show();
                bw_get.RunWorkerAsync();
                bw_get.DoWork += bw_getDevices;
                bw_get.RunWorkerCompleted += bw_getDevices_Completed;
                //bw_get.ProgressChanged += bw_getDevices_ProgressChanged;

                GuiList.Clear();

                activeType = HCB.type.device;
                GUIPropertyManager.SetProperty("#hcb.activeType", "Devices");
            }
..........

        void bw_getDevices(object sender, DoWorkEventArgs e)
        {
            try
            {
                e.Result = h.getDevices();    // This gets passed to RunWorkerCompleted
            }
            catch (Exception ex)
            {
                Log.Error("bw_getDevices: " + ex.Message);
            }
        }

        void bw_getDevices_Completed(object sender, RunWorkerCompletedEventArgs e)
        {
            
            try
            {
                devicesList = (SortedList)e.Result;

                foreach (device d in devicesList.Values)
                {
                    GUIListItem item = new GUIListItem();
                    item.OnItemSelected += new MediaPortal.GUI.Library.GUIListItem.ItemSelectedHandler(listSelectDevice);
                    item.Label = d.name;
                    item.Label2 = d.type;
                    item.ItemId = d.id;
                    item.IsPlayed = d.status;

                    GuiList.Add(item);
                }
                GUIPropertyManager.SetProperty("#itemcount", GuiList.Count.ToString());
                Log.Info("HCB: Devices listed");

                GUIWaitCursor.Hide();
            }
            catch (Exception ex)
            {
                Log.Error("bw_getDevices_Completed: " + ex.Message);
            }
        }

Download whole project here: http://dl.dropbox.com/u/21558454/MP_HomeControlBox.zip

I hope it's all alright now But there is a big chance that my coding is all wrong..
Give me some feedback please.

 

[Dragy]

It works on my computer (i7 8 virtual cores), but on the HTPC (2 cores) it only works at random times.. I get this error very often:

bw_getDevices_Completed: object reference not set to an instance of an object.

I cannot understand why it only works randomly..
Also the bw_getMacros works mostly only after the first time. So the first time it just doesn't get all the macros..

//edit
OMG, I think I've fixed it now!
Instead of this:

bw_get_devices = new BackgroundWorker();
[B]bw_get_devices.RunWorkerAsync();[/B]
bw_get_devices.DoWork += bw_getDevices;
bw_get_devices.RunWorkerCompleted += bw_getDevices_Completed;

I use now this (duh):

bw_get_devices = new BackgroundWorker();
bw_get_devices.DoWork += bw_getDevices;
bw_get_devices.RunWorkerCompleted += bw_getDevices_Completed;
[B]bw_get_devices.RunWorkerAsync();[/B]