Scroll control doesn't work properly

[ttool22]

C# code is below

var scrollView = new ScrollView();
scrollView.X = 0;
scrollView.Y = 0;
scrollView.Width = Dim.Fill();
scrollView.Height = Dim.Fill();
scrollView.ContentSize = new Size(Console.WindowWidth, Console.WindowHeight * 2);

---

When I scroll down, I got this error(below), I have win 11 ;(

A clear and concCollection was modified; enumeration operation may not execute.
at System.Collections.Generic.List1.Enumerator.MoveNext() at Terminal.Gui.View.Redraw(Rect bounds) at Terminal.Gui.FrameView.Redraw(Rect bounds) at Terminal.Gui.View.Redraw(Rect bounds) at Terminal.Gui.ScrollView.Redraw(Rect region) at Terminal.Gui.View.Redraw(Rect bounds) at Terminal.Gui.Window.Redraw(Rect bounds) at Terminal.Gui.Application.RunMainLoopIteration(RunState& state, Boolean wait, Boolean& firstIteration) at Terminal.Gui.Application.RunLoop(RunState state, Boolean wait) at Terminal.Gui.Application.Run(Toplevel view, Func2 errorHandler)
at Terminal.Gui.MessageBox.QueryFull(Boolean useErrorColors, Int32 width, Int32 height, ustring title, ustring message, Int32

[BDisp]

I couldn't reproduce this. I see you are using the scroll inside a frame. On what Terminal.Gui version you are running, v1 or v2?

[tznind]

Or if you are using the Nuget package? If so what version? Are you able to provide a link to your source code or give any more details. For example where do you launch the View, do you call Application.Init etc.

[ttool22]

I ha have 1.72 version with win 11, I have added scroll inside window
win.Add(scrollView);
Application.Run(win, (e) =>
{
MessageBox.ErrorQuery("Error", e.ToString(), "Ok");
return false;
});

[ttool22]

When I run my app on win 11, controls are mixed then I fix it by expanding the window with the mouse.

[BDisp]

I recommend you to download the current v1 from the repo, which is the develop branch and check if the issue still exist.

[ttool22]

I work with frame in scrollView, I fill it dinamic also I can't delete frame, I tryed FrameView.SubViews[0].Subviews.Clear(); but it throws error

FrameView FrameControl = new FrameView()
{
X = 0,
Y = 30
Width = 120,
Height = 0,
Border = new Border() { BorderStyle = BorderStyle.None, BorderThickness = new Thickness(1, 1, 1, 1) },
Visible = false,
Id = "Frame"
};
FrameControl .Add(new Label() { Y = brLines * 4, X = 12, Text = "1" });
FrameControl .Add(new Label() { Y = brLines * 4, X = 24, Text = "x", });
FrameControl .Add(new Label() { Y = brLines * 4, X = 36, Text = "2" });****

[ttool22]

When scroll controls become mixed then throw this error

[BDisp]

You can't remove the FrameView with FrameView.SubViews[0].Subviews.Clear(). If you added the FrameView into the ScrollView and want to remove it you have to use scrollView.Remove(FrameControl);.

[BDisp]

This scenario https://github.com/gui-cs/Terminal.Gui/blob/develop/UICatalog/Scenarios/ASCIICustomButton.cs use a FrameView inside a ScrollView. Maybe it can help you to check what you are doing wrong.

[tig]

This scenario https://github.com/gui-cs/Terminal.Gui/blob/develop/UICatalog/Scenarios/ASCIICustomButton.cs use a FrameView inside a ScrollView. Maybe it can help you to check what you are doing wrong.

I don't think that's a great sample. It's quite convoluted.

Character Map also shows this, but it too does a lot of other things.

[ttool22]

Neither do I, btw labels not clickable anymore in the latest version, lot of bugs...

[ttool22]

Why I have this problem on win 11?

[ttool22]

Controls are mixed by default

[BDisp]

Very strange. Do you are using Windows Terminal?

[ttool22]

Yes it is windows console

[ttool22]

When I scroll up, it throws this error in windows terminal, I don't have any clue how I can resolve it

[ttool22]

[ttool22]

Is the problem with windows driver or sth else?

[BDisp]

When I scroll up, it throws this error in windows terminal, I don't have any clue how I can resolve it

It seems that you are removing some views while Redraw and LayoutSubviews is running. You can't do it on Redraw. It's possible to you upload to your github a simple demo that reproduce this issue? If you want to test with another driver put Application.UseSystemConsole = true before Application.Init().

[ttool22]

Yes every one sec I have to use the same frameView with new data. The frameview contains some controls(labels and textfields). How can I do scroll and represent these dates in frameView? Can you write some lines with small example? The important thing is that frameView creates dinamically. My question is that how I can do scroll and fill data every sec in frameview?

[tznind]

When updating Terminal.Gui from a Thread, the most important thing to do is to ensure any UI related code goes via Application.MainLoop.Invoke. This is how cross thread UI access is managed in Terminal.Gui. I can provide you with a more detailed example later but this may get you started.

[BDisp]

@tznind thanks for clarifying.
If you had said soon you were using threads, that would be more easy. If you are initializing the FrameView every one sec on a thread, then you have to do this inside the thread method:

Application.MainLoop.Invoke () => {
scrollView.Remove(FrameControl);
FrameView FrameControl = new FrameView()
{
X = 0,
Y = 30
Width = 120,
Height = 0,
Border = new Border() { BorderStyle = BorderStyle.None, BorderThickness = new Thickness(1, 1, 1, 1) },
Visible = false,
Id = "Frame"
};
FrameControl .Add(new Label() { Y = brLines * 4, X = 12, Text = "1" });
FrameControl .Add(new Label() { Y = brLines * 4, X = 24, Text = "x", });
FrameControl .Add(new Label() { Y = brLines * 4, X = 36, Text = "2" });
scrollView.Add(FrameControl);
};

[ttool22]

Thank you guys, it doesn't throws error but scroll does not work smoothly after some period

[ttool22]

I call it on this way Application.MainLoop.Invoke(async()=> { await RepresentData })}); RepresentData is a Task

[BDisp]

Thank you guys, it doesn't throws error but scroll does not work smoothly after some period

Because your are forcing it redrawing every one sec. Maybe you can increase that. Try this to enforce FrameControl disposing before recreating.

scrollView.Remove(FrameControl);
FrameControl.Dispose();
FrameControl=null;
...

[BDisp]

I call it on this way Application.MainLoop.Invoke(async()=> { await RepresentData })}); RepresentData is a Task

That's ok, but you still must use inside the RepresentData again the Application.MainLoop.Invoke to recreate the FrameView.

[tig]

Doesn't seem like there's a bug here. Reopen if I'm wrong.