CODEWITHSUNDEEP
c#wpflistview
Christian
Christian

Reputation: 4375

Scrolling of ListView containing Expanders which contain ListViews does not work

I have the situation that my C# WPF application contains a ListView whose elements are Expanders. Each of those expanders contains a ListView with ListViewItems. Here is a picture: enter image description here

On the right you can see a Scrollbar. And that ScrollBar is my problem. It has got two issues:

  1. The ScrollBar does not work when using the MouseWheel over the expanded list. By that I mean the area from "Controller" down to "FullInstallation". If hovering over the header ("All Tests"), the ScrollBar does scroll. I think that the ListView inside the Expander by default has a ScrollBar which "steals" the MouseWheel event. However, I don't know what to do against it.

  2. The ScrollBar scrolls over the Expander items and not the content of the expanders. By that I mean, that it is not possible to scroll a little bit down, instead you always scroll at least 1 Expander item down. I would like the scrollbar to scroll such that it is possible to see for instance one half of the "All Tests" Expander.

The picture shows a disabled scrollbar, but by making the window smaller, the scrollbar gets enabled.

What I have tried so far:

  1. ScrollViewer outside the outer ListView: This solves Problem 1, however it means that the MouseWheel does not work at all! That is because the outer ListView generates its own ScrollViewer (used Snoop to find this out) which "steals" the MouseWheel events.

  2. Redirected all the MouseWheel events of all the controls (ListView, Expander, ListViewItem) to the ScrollViewer: Again I used a ScrollViewer outside of the outer ListView and this time I used the MouseWheel event for all my controls to call the MouseWheel event of the outer ScrollViewer. This did work, however for some locations of the mouse pointer it didn't. For instance between two ListViewItems there is a small 1 millimeter space where the MouseWheel event is not catched. Or at the bottom after the last Expander ("Short Tests"). There I do not get any event.

I tried a couple more things but did not get any further. Does anyone have an idea how to solve this?

Best wishes, Christian

Upvotes: 5

Views: 2938

Answers (1)

Wallstreet Programmer
Wallstreet Programmer

Reputation: 9677

1) For how to write an attached behavior to control mousewheel behavior when you have nested itemscontrols, see: WPF Nested ScrollViewer / ListBox Scrolling

2) Non virtualized itemscontrol supports smooth scrolling, see: Is it possible to implement smooth scroll in a WPF listview?

Upvotes: 3

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