I want to prevent the ability to deselect a list view item if it is already selected. Therefore how do I prevent right mouse click ability to deselect an item?
I have prevented the ability to deselect via swiping by using IsSwipeEnabled="False" on the List View. I didn't require swipe ability on the list view.
I'm happy to completely prevent right mouse click on the list view items if needed.
If I am reading your question correctly, it sounds like you want the ability for the user to select items, but to not be able to de-select. If that is the case, it seems like a strange requirement - it goes against normal UI convention and does something that the user is not expecting.
Having said that, you can do so by handling the SelectionChanged event in the ListView.
When the event is triggered, it gives you a list of removed (de-selected) items. You then just need to add those items back into the ListView's selected items list:
private void itemListView_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
foreach (var item in e.RemovedItems)
{
itemListView.SelectedItems.Add(item);
}
}
Note that if you use the above code, you do not have to handle any swipe or mouse events.
Edit - Per OP's comment, the requirement is slightly different than what I thought:
I want the selected item to deselect if a different item is selected. however what I dont want is an already selected item to be (manually) deselected
Assuming that you have a single select ListView, you can still use the SelectionChanged event and the SelectionChangedEventArgs to do what you are asking for:
private void itemListView_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (e.RemovedItems.Count > 0 && e.AddedItems.Count == 0)
{
var removed = e.RemovedItems[0];
itemListView.SelectedItem = removed;
}
}
I have found a simple solution on the following forum.
You simply add a RightTapped event to the ListView DataTemplate content.
<ListView>
<ListView.ItemTemplate>
<DataTemplate>
<ContentPresenter RightTapped="daves_RightTapped" />
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
And then in the code behind:
private void daves_RightTapped(object sender, Windows.UI.Xaml.Input.RightTappedRoutedEventArgs e)
{
e.Handled = true;
}
This works fine on an outlook style ListView.
Related
I am making a UWP app which is supposed to be on xbox for now and maybe in future ill release it on pc and other platforms. I know that on PC and for mobile we can enable this feature with following 2 properties on the GridView or ListView.
CanReorderItems=True
CanDrop=True
But according to Microsoft Docs, drag and drop feature is not available or supported on xbox.
So what are any other options to achieve this reorder feature on xbox GridView?
UPDATE 1
So here is my backend code for the gridview. selection mode is single but I am not using selectionchanged event because that just creates lot of confusion and for now just assume that we always need to swap the items I will set the boolean later once the swapping in working perfectly.
private void SamplePickerGridView_ChoosingItemContainer(Windows.UI.Xaml.Controls.ListViewBase sender, ChoosingItemContainerEventArgs args)
{
if (args.ItemContainer != null)
{
return;
}
GridViewItem container = (GridViewItem)args.ItemContainer ?? new GridViewItem();
//should be xbox actually after pc testing
if (DeviceTypeHelper.GetDeviceFormFactorType() == DeviceFormFactorType.Desktop)
{
container.GotFocus += Container_GotFocus;
container.LostFocus += Container_LostFocus;
//container.KeyDown += Container_KeyDown;
}
args.ItemContainer = container;
}
private TVShow GotItem, LostItem;
private void Container_LostFocus(object sender, RoutedEventArgs e)
{
LostItem = OnNowAllGridView.ItemFromContainer(e.OriginalSource as GridViewItem) as TVShow;
GotItem = null;
}
private void Container_GotFocus(object sender, RoutedEventArgs e)
{
GotItem = OnNowAllGridView.ItemFromContainer(e.OriginalSource as GridViewItem) as TVShow;
if (GotItem != null && LostItem != null)
{
var focusedItem = GotItem;
var lostitem = LostItem;
var index1 = ViewModel.Source.IndexOf(focusedItem);
var index2 = ViewModel.Source.IndexOf(lostitem);
ViewModel.Source.Move(index1, index2);
}
LostItem = null;
}
u can try the code with adaptivegridview or just normal gridview of uwp if it works with that it should work with adaptivegridview as well.
Current Bheaviour items are swaped but the focus remains at same index.
Expected the focus should also move along with the item.
Your finding is true, drag and drop is not supported on Xbox out of the box (although when mouse support comes to Xbox in the future, I guess it will work).
So if you need this functionality, you will have to implement it manually from the start. One option would be to add a button, that will display on Xbox only and will read like Reorder Grid.
When this "reorder" mode were enabled, you have several solutions available.
The easiest solution for you would be to set the SelectionMode to Single and when a item is selected, you would bring it to fromt of the underlying collection.
collection.Remove( selectedItem );
collection.Insert( 0, selectedItem );
This bring to front solution was implemented on the Xbox One dashboard for reordering tiles.
Second option would be to set the SelectionMode to Multiple, where user would first select one item and then a second one. After that you could move the first selected item before the second selected:
collection.Remove( firstSelectedItem );
var targetIndex = collection.IndexOf( secondSelectedItem );
collection.Insert( targetIndex, firstSelectedItem );
The last solution is the most complex. With SelectionMode = Single you would select a single item and then observe the direction in which the user focus moves and move the tile "in real time". This is the most user friendly, but hardest to implement reliably.
Just as an outline of the third solution - you could capture the GotFocus event if you implement a custom template of the GridView:
<GridView.ItemsPanel>
<ItemsPanelTemplate>
<ItemsWrapGrid Orientation="Horizontal"
GotFocus="GridViewItem_GotFocus"/>
</ItemsPanelTemplate>
</GridView.ItemsPanel>
Now within this GotFocus handler you could retrieve the item that has currently focus from the EventArgs.OriginalSource. This way you could know which item got the focus and you could swap it with the item the user selected.
Update - hacky solution
I have come up with a hacky approach that solves the GotFocus/LostFocus mess.
The problem with GotFocus is that when we move the item in collection, the focus gets confused. But what if we didn't physically move the items at all?
Suppose your item type is TVShow. Let's create a wrapper around this type:
public class TVShowContainer : INotifyPropertyChanged
{
private TVShow _tvShow;
public TVShow TvShow
{
get => _tvShow;
set
{
_tvShow = value;
OnPropertyChanged();
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
Now change the collection item type to this new "wrapper" type. Of course, you also have to update your GridView DataTemplate to have the right references. Instead of "{Binding Property}" you will now need to use "{Binding TvShow.Property}", or you can set the DataContext="{Binding TvShow}" attribute to the root element inside the DataTemplate.
But you may now see where I am going with this. Currently you are using Move method to move the items in the collection. Let's replace this with a swap:
var item1 = focusedItem.TvShow;
focusedItem.TvShow = LostItem.TvShow;
LostItem.TvShow = item1;
This is a big difference, because we no longer change the collection itself, but just move the references to items that are wrapped in a "static" container. And thanks to bindings the items will properly display where they should.
This is still a hacky solution, because it requires you to wrap your items just for the sake of the reordering, but it at least works. I am however still interested in finding a better way to do this.
I've searched and I've not found the answer yet.
I need to disable the click that happens in each item of a list and makes it be blue, as if it is selected. The problem is that my list items aren't selectables items, my list is only for the user see some informations.
you can use IsEnabled = "False" as Barney said Or otherwise asign null value to selected item after selection event.
<ListView ItemSelected="ListView_ItemSelected" />
...
private void ListView_ItemSelected(object sender, SelectedItemChangedEventArgs e)
{
var list = (ListView)sender;
list.SelectedItem = null;
}
Add IsEnabled="False" into your ListView as shown here
<ListView IsEnabled="False">
I've implemented a UWP SplitView similar to the one made by Diederik Krols. I prefer the approach of using a ListView over using RadioButtons as shown by Jerry Nixon's implementation of the SplitView.
However, I have a problem when I add secondary commands at the bottom of the SplitView, which Diederik doesn't do. These secondary commands are implemented by another ListView bound to a collection of Commands. So I have TWO ListViews that should only allow ONE item to be selected among them at a time.
I've tried two things:
I've bound the SelectedItem property of both ListViews to the same object. The idea was that maybe ListView doesn't display a selection if SelectedItem is not in the list bound to ItemsSource. Sadly, it simply goes on displaying the last selected item.
I've bound each ListView's SelectedItem to its own property. When one of the ListViews' item is selected, the SelectedItem of the other property is set to 'null' by the ViewModel. This produces the same result as in 1.
Any ideas on how to solve this problem?
I had the same problem.
I have a fix, but I'm not that proud of it ;) it's a dirty hack and I'm hoping other solutions will present itself so I can change it too.
But here it is:
First the listviews hook up to the SelectionChanged event even though we also bind the selected item to the viewmodel ( full code shown here https://github.com/AppCreativity/Kliva/blob/master/src/Kliva/Controls/SidePaneControl.xaml )
<ListView x:Name="TopMenu"
SelectionChanged="OnTopMenuSelectionChanged"
Background="Transparent"
ItemsSource="{x:Bind ViewModel.TopMenuItems}"
ItemTemplateSelector="{StaticResource MenuItemTemplateSelector}"
ItemContainerStyle="{StaticResource MenuItemContainerStyle}"
SelectedItem="{x:Bind ViewModel.SelectedTopMenuItem, Mode=TwoWay, Converter={StaticResource XBindItemCastingConverter}}"
Grid.Row="0" />
In that SelectionChanged, we'll deselect the 'other' listviews selection! ( full code shown here https://github.com/AppCreativity/Kliva/blob/master/src/Kliva/Controls/SidePaneControl.xaml.cs )
Note that we need to keep track that we are already in a deselecting process otherwise we'll end up with an endless loop. This is done with the _listViewChanging field.
private void OnBottomMenuSelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (!_listViewChanging)
{
_listViewChanging = true;
TopMenu.SelectedIndex = -1;
_listViewChanging = false;
}
}
Last thing to do is making sure we handle the selection and clear it again in the viewmodel for next itteration ( full code shown here https://github.com/AppCreativity/Kliva/blob/master/src/Kliva/ViewModels/SidePaneViewModel.cs )
public MenuItem SelectedBottomMenuItem
{
get { return _selectedBottomMenuItem; }
set
{
if (Set(() => SelectedBottomMenuItem, ref _selectedBottomMenuItem, value))
{
if (value != null)
{
if (string.IsNullOrEmpty(SelectedBottomMenuItem.Title))
HamburgerCommand.Execute(null);
if (SelectedBottomMenuItem.Title.Equals("settings", StringComparison.OrdinalIgnoreCase))
SettingsCommand.Execute(null);
SelectedBottomMenuItem = null;
}
}
}
}
I'm using Caliburn.Micro and the LongListSelector. Because binding SelectedItem is a problem I act on the SelectionChanged event. Problem is, after returning to the list, when I click the same item again, it is already selected. So the event doesn't fire. I could set the SelectedIndex to -1 or something, but in Caliburn.Micro I can't access UI controls. That's the point of MVVM, isn't it?! :)
Here's my XAML
<LongListSelector x:Name="NewsItems"
ItemsSource="{Binding NewsItems}"
cal:Message.Attach="[Event SelectionChanged] = [NavigateToArticle($eventArgs)]" />
How to solve this? How can I reset the SelectedItem when I can't access the LongListSelector from code?
Thanks!
You have to put your LongListSelector SelctionMode="Multiple",
or
You can get it using Gesture Tap event.
Did not understood real problem but
I think you can solve your problem if selection change event fire every time when user select item-
private void productList_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
LongListSelector productList= (LongListSelector)sender;
if (productList.SelectedItem == null)
return;
//Write your code here
//For Tapping many times..
productList.SelectedItem = null;
}
The above code will make selection change event to fire on selection of same item every time.
I have a WinRT/C#/XAML app with a view that has a vertical ListView of items. Depending on the amount of items the ListView shows a vertical scrollbar. Here's the XAML definition:
<UserControl.Resources>
<CollectionViewSource
x:Name="myViewSource"
Source="{Binding myViewModel.Items}" />
</UserControl.Resources>
...
<ListView
x:Name="myListView"
ItemsSource="{Binding Source={StaticResource myViewSource}}"
SelectedItem="{Binding SelectedItem, Mode=TwoWay}">
</ListView>
Now everytime I navigate to this view, the selected item of the ListView is chosen by setting the databound SelectedItem property in the view model from code behind (OnNavigatedTo). My problem: the ListView doesn't scroll automatically to this selected item. The scrollbar remains at the top of the ListView and the user has to scroll manually to see the selected item.
I tried to execute myListView.ScrollIntoView(MyViewModel.SelectedItem); after setting the SelectedItem in the code behind (in OnNavigatedTo), but it doesn't work. The scrollbar remains at the top.
I'm aware of this thread on SO: Scroll WinRT ListView to particular group .
This seems to be a similar problem. But when I walk the visual tree of the ListView manually or with the WinRT XAML Toolkit, it doesn't find a ScrollViewer (returns null instead).
Thanks to Filip I noticed that calling ScrollIntoView() in OnNavigatedTo() was too early, because the ListView control is not loaded yet in this place.
The first solution idea was to bind the Loaded event of the ListView:
myListView.Loaded += (s, e) =>
myListView.ScrollIntoView(MyViewModel.SelectedItem);
Unfortunately that causes a nasty visual effect, where current ListView items overlap with the selected item for parts of a second, before everything is rearranged well.
The final solution I found is to call ScrollIntoView() asynchronously via the Dispatcher of the view:
myListView.Loaded += (s, e) => Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
() => myListView.ScrollIntoView(MyViewModel.SelectedItem));
With this solution the layouting works fine.
I had a similar need and resolved it in a slightly different manner. I subscribed to the SelectionChangedEvent from the ListView and performed the scrolling within the handler.
XAML:
<ListView x:Name="myListView" SelectionChanged="myListView_SelectionChanged" ...>
</ListView>
Code:
private void myListView_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
myListView.ScrollIntoView(myListView.SelectedItem);
}