Question

The following problem:

I want to upload files in a program, and the user should be able to make settings.
Because the files are very large, I would like to load them into a new thread so the user can make additional settings in the GUI. (Speed: fast)

1. User select file
2. Program start a new thread
3. the thread is loading the file
4. program calls the dispatcher to set the file into the layout

So far so good, step one to three works without problems.

But in step 4, I make a Dispatcher.Invoke.

private void SetNewContent(object newContent)
{
    _userControl.Dispatcher.Invoke(
        DispatcherPriority.Normal,
        new System.Action(
            delegate()
            {
                _userControl.SetContent(newContent);
            }
        )
    };
}

The method _userControl.SetContent is slow. The method takes about 5 seconds for 10,000 pages, which is too long for the user. During this time, the user can not make changes to the GUI settings.

Is there a possibility to prevent it?

Answer 1

You shouldn’t render all content at once. Display only visible content.
If “newContent” is a collection (or can be wrapped into collection), you can bind it to any WPF list controls via “ItemsSource” property – they are virtual, so they will render only visible items.