I have a Listview that uses a grid for its ItemsPanel instead of a stackpanel (a stackpanel won't suffice).
The ItemsSource of a grid is bound to a CompositeCollection of various items; and the items, of different classes, are not ordered (i.e., first item is not necessarily in 1st row/ 1st column; it's possible that last item in the list may physically be found on the top row of the grid).
So now I am not able to use VirtualizingStackPanel,... when I check Snoop, the ListView lists all items in the ItemsSource even when they're not visible.
Question: Is there a way to virtualize contents inside of the grid?
Related
Background: I have a WrapPanel with Vertical Orientation that I want to put up to 40 "items" in. Each "item" within the WrapPanel will contain a combination of buttons and expandable lists in a 5x6 grid format. I need to be able to select each "item" within the WrapPanel so it brings up a dialogue box where the user can click the buttons and edit the expandable lists for that "item".
Question: I understand that the main difference between ItemsControl and ListBox is that the entities inside a ListBox are selectable while the ones in ItemsControl are not, however I do not need to select values inside my ItemsControl or ListBox until my dialogue appears, so I'm not sure if it would be best to use the ItemsControl or ListBox in this situation. Which ListControl would be best for my situation?
If your root items should be selectable you would probably want a ListBox whose ItemsPanel is a WrapPanel. If you don't need actual selection (i.e. it does not matter that items automatically deselect, or that operations are executed on the set of selected items) you can just use an ItemsControl with a WrapPanel as ItemsPanel and use a big Button as the root of your ItemTemplate (to trigger the dialog).
I'm developing windows metro app. In my application, I've one Listview with wrapgrid in itemspanel to display list of items on vertical rows with specific height. I want to display one item on top of the first column of list view, which shows result/stats of list items.
I would like to know if it is possible without adding custom item to datasource of listview?
ListView has a Header property in which you can Place content before the ListViews Items.
As commented, I've implemented following solution which is not elegant but worked for me.
Use Datasource converter to add dummy item in main list. So, my original list remains as is.
Use Template Selector to bind different template for first item.
Handle Selection and clicked event of dummy item.
I'm using a Multiselect Treeview in MVVM WPF App. A ReactiveCollection is binded as the treeview source. Implemented paging mechanism internally for the source and populated the collection with dummy items.
Now I need to how many items (rows) in the treeview are actually visible in the GUI at any point of time and when the user scrolls. Basically, I want to know the first and last item index in the visible view at any given time and I will implement paging based on this item(row) index and scrolling.
And this logic to detect item index must be implemented as a behaviour for itemscontrol, so that I can reuse it for any itemscontrol.
I have a DataGrid with a bunch of rows representing items in my system. I want that each time a user selects an item in the grid (the user is allowed to select multiple items) the item will be added to a StackPanel and have its own datatemplate using an Expander to display its data.
Can anyone help me do this in WPF?
Thanks!
John.
I wouldn't use a StackPanel, but an ItemsControl, and bind its ItemsSource to the DataGrid's SelectedItems. However, at the moment I'm not sure whether SelectedItems has change notification. If not, you might have to use a CollectionViewSource in between, and call CollectionViewSource.Refresh during the DataGrid.SelectionChanged event.
In my wpf project I'm using a datatemplate (which consists of a textblock) as an itemtemplate to my listbox. The itemsource is a List of which there are 6 items. How can I loop through the 6 textblock's that are created at runtime?
Thanks
Do not do it.
Bind everything you need to change to your items and then just change the bound properties, messing with template controls is never a good idea, especially with virtualizing items controls where they may not even exist for all items.
(What you should not use: ItemsControl.ItemContainerGenerator.ContainerFromItem)