WPF ListBox item load step-by-step animation - wpf

I want to create user control based on ListBox (ListView) with such animation: the items in listbox do not loads all at once, they have to load step-by-step (item-by-item, first then second, then third, etc.) with some timeout between them.
How can I do that?
Thanks in advance for your help :)

The suggested Slide Animation is a view animation. I think you want a data animation. Bind to an alternate view only collection. Populate this collection one at a time from the backing collection with the aid of a timer. A quick search reveals that a Dispatch Timer seems to be preferred with WPF usage.

Related

WPF: How to update UI without blocking animations

in my WPF application I have a ListView with a GridView as it's View. The ItemsSource of the ListView is bound to an ItemsCollection in the ViewModel.
This GridView has a lot of columns and the ListView can have a lot of items.
When the windows is loading or the user updates this ListView I show a loading animation while retrieving the new data from the server and updating the ItemsCollection in the ViewModel with the new data.
This retrieving of data is already done asynchronously, so the loading animation keeps spinning. But as soon as the data is retrieved and the binding is to update the ListView, the loading animation freezes until the update of the UI is finished.
How can I make my loading animation keep spinning even when the binding updates the UI?
Thank you for your help.
EDIT:
Well, that binding runs in the main thread, the same thread your animation runs.
Clearly my previous solution wont help you. You will have to find a way to reduce the time it takes to rendering view. Share some working code, maybe someone can help you.
Other alternative is to stop the animation and show something static. That way you hide the problem. Its not a great solution, but if you don't find other, this could your only one.

Silverlight How to load a usercontrol in a page based upon a listbox selection

I am trying to work though the best approach to accomplish the following. Within a page I have it divided into two section. On the left a listbox and the right is empty. (Grid etc). What I would like to accomplish is when an item is selected from the listbox a different user control loads in the right panel. For example if I have three items (one, two three) selecting one would load a red user control, two would load a blue user control and three a green user control.
I was taking this approach since Content Template / Data template selectors are not available in SL. However if anyone has another suggestion I would be grateful for your thoughts.
I'm creating this with MVVM in mind and traditionally I have managed this within the code behind of the user control however I have seen mention of how this could be managed within the ViewModel as well.
Any suggestions or guidance on a best approach is always appreciated.
Cheers
You can bind both listbox selected item and user control visibility properties to the same property in the viewModel.
Then just use a valueConverter for each user control to switch on/off the visibility.
Please tell me if i should elaborate/add a code sample.

Show Loading Image when TreeView Node is clicked in WPF

The question is we have a WPF application, which has Tree View. On the click of node Report gets generated which has no time interval (I mean no clue how much time it will take). So I am planning to show a Loading.gif file on the window till the report is generated.
How can I make the image (.gif) visible while the main window process to show the report and after showing the report I need to hide the image.
Do you have any other alternate method to do so.
Appreciate your help in advance.
You can make use of Extended WPF Toolkit's BusyIndicator.
Here's a sample of how to make async multi-threaded treeview -> http://www.codeproject.com/KB/WPF/ThreadedWPFExplorer.aspx
The general technique for this is:
1) Create an IsBusy property in the view model for your window; make sure it raises PropertyChanged when it changes.
2) In the code executed when the item is clicked, use a BackgroundWorker to run the long-running task.
3) Before calling BackgroundWorker.DoWork(), set IsBusy to true. In the event handler called when the BackgroundWorker.RunWorkerCompleted is raised, set IsBusy to false.
4) In the DataTemplate for the window, add a Style with a DataTrigger bound to IsBusy, and use that to control the visibility of the image.
Note that you may be able to move IsBusy (and the long-running task and the BackgroundWorker) to the item view model instead of the window view model, and add a "Loading" animation to the DataTemplate for the item.
If you do this, the user can start multiple items loading simultaneously, and the entire application doesn't lock up just because one item in the TreeView got clicked on. (Of course, you have to deal with any multithreading issues involved in generating multiple reports simultaneously).

Animating through listbox items in Silverlight 4

I have a ListBox bound to a collection of custom objects. I have an ItemTemplate set up for displaying those items. Each item takes up a large rectangular area, so what I want to do is actually only display one item at a time. After ten seconds, I want to animate (maybe slide in/out or fade in/out) to the next item so that only that one is displayed and so on.
I can't get to grips with how to achieve this, can anyone help please?
Maybe a listbox isn't even the right approach?
If you are not dead set on using a listbox, you can get this effect using a TransitioningContentContol instead. How-to Video here (the control is in system.Windows.Controls.Layout.Toolkit). It is now part of the released toolkit (the video is old).
Part of the demo shows how to emulate exactly the behaviour you are after. You can add a slider to the side if you still want it to look a bit like a listbox (and change the selection in response to the slider value changes).

Is it possible to get notification while adding items into itemsControl using Add() method in WPF

Actually I'm using an items control and animating the children of it. The problem is when adding the items dynamically through Add() method the first item is not getting animated and just comes to display as usual.
I've planned to hide the dynamically added child and later make it visible when i want to use it with animation and that way i can bring it into view with animation.
To hide the child when it gets added dynamically i need some kinda of notification or event fired for Add() method!. I tried using InotifyCollectionChanged but that didn't work.
Your thoughts please..
Your alternative suggestions are also appreciated..
Thanks in advance...
First option is to check this question: Animate WPF Datatemplate when item added to Listbox?.
Another option would be to create your own ItemsControl and override OnItemsChanged() method. But it's not as easy as the first option.
Hope this helps.
I'd probably bind the listbox to a collection in a ViewModel, and add directly to that rather than adding to the ListBox.
Hi guys i found the solution for my problem, this may help those who are struck with such an issue.
This can be achieved by using a grid as your itemsHost and dynamically adding the children of itemscontrol to the grid and animating it. since the grid get its children only at the runtime we have more control over it and decide when it should be rendered on the screen.

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