Develop Reference

Reordering ListBox elements with gong-wpf-dragdrop causes visual bugs

Task
My task was to be able to change the order of the service cards in the ListBox by dragging and dropping. I found a good solution on StackOverflow that has a lot of useful features (gong-wpf-drag drop, https://stackoverflow.com/a/33367826/19631476).
Problem
However, I had to face an unpleasant visual bug: when I drag the service card, there is some label that indicates where the dragged object will be moved. So, for some reason, this label is clipped if a number of objects are also clipped and not visible in the ListBox. However, when scrolling, the cropping does not disappear. Moreover, then the label will always point to the line above, wherever it is.
Problem demo
below I will present some screenshots demonstrating the problem
the normal state of the separator
the separator is cut off due to the fact that the card does not fit into the container
the separator continues to be cut off after scrolling
the separator is shifted up a line, and is still clipped, despite the fact that I move the elements already in another line
My code
This is how my ListBox element looks like:
<ListBox
Margin="10 0 10 10"
Background="Cornsilk"
MinWidth="300"
ScrollViewer.HorizontalScrollBarVisibility="Disabled"
dd:DragDrop.IsDragSource="True"
dd:DragDrop.IsDropTarget="True"
dd:DragDrop.SelectDroppedItems="True"
ItemsSource="{Binding ServicesListCollectionView.View}"
SelectedIndex="{Binding SelectedServiceIndex}"
SelectedItem="{Binding SelectedService}"
d:ItemsSource="{d:SampleData ItemCount=5}">
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemTemplate>
<DataTemplate>
<Border AllowDrop="True" Style="{StaticResource BorderStyle}">
<DockPanel Background="GhostWhite">
<!-- Service Card Template-->
</DockPanel>
</Border>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
it contains a custom container so that the service cards can be arranged as a grid from top to bottom
What have I tried to do?
The idea came to my mind to prohibit the use of ScrollBar for the ListBox element. It worked, and the visual bug sort of disappeared. But you can't leave it like that. I wrapped the ListBox in ScrollViewer and allowed it to scroll vertically. This visual bug is no longer there:
code:
<ScrollViewer VerticalScrollBarVisibility="Auto" x:Name="ServiceScroll">
<!-- Here is ListBox -->
</ScrollViewer>
However, this solution is not suitable:
I lose control of scrolling in the ListBox and can only use scrolling on the ScrollViewer itself
Scrolling also becomes unavailable when dragging items.
the second problem can be solved by specifying the dd:DragDrop.DropTargetScrollViewer ScrollViewer with binding to the ScrollViewer element:
<ScrollViewer VerticalScrollBarVisibility="Auto" x:Name="ServiceScroll">
<ListBox
...
dd:DragDrop.IsDragSource="True"
dd:DragDrop.IsDropTarget="True"
dd:DragDrop.SelectDroppedItems="True"
dd:DragDrop.DropTargetScrollViewer="{Binding ElementName=ServiceScroll}"
...
></ListBox>
</ScrollViewer>
but in this case, the visual bug described above appears again, and also, this solution still does not allow you to scroll through the elements inside the ListBox using the mouse wheel.
Any ideas?
To be honest, I do not know what to do. Has anyone encountered anything described above?
Maybe I'm doing something wrong, which is why I get such strange behavior? What's wrong with scrolling?
Maybe you have good solutions to solve the problem? How else would it be possible to solve the issue of dragging items to the ListBox in the most flexible way?

How can I design a region settings like this in WPF

Till now I have a combo-box control which displays all the available region language in the UI as a combo-box items.
its in WPF and MVVM
<ComboBox
x:Name="cbLanguage"
Grid.Row="1"
Height="30"
Width="200"
HorizontalAlignment="Center"
VerticalAlignment="Top"
ItemsSource="{Binding LocalLanguages,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
SelectedIndex="0">
But I saw this window and thought this looks much more legant and modern.
Can I do similar kind of window in WPF.
I tried to change the Combobox with list-box, List-view but no result.
Any help if there is any control in WPF which can do this.
This solves many problem specially if the combo box have more than 10 items user has to scroll through the all and then select the last index. But in this way user can select any locals as all are displayed in the UI. Even user can have the option to display alphabetically.

arraging items in 3 columns can be achieved by using UniformGrid as ItemsPanel
<ComboBox.ItemsPanel>
<ItemsPanelTemplate >
<UniformGrid Columns="3"/>
</ItemsPanelTemplate>
</ComboBox.ItemsPanel>
modify ItemTemplate to change items apperance and have green color for selected item
i think it is necessary to modify ComboBox template to have custom header and footer in a dropDown (Edit Template-Edit a Copy in Visual Studio designer)

In WPF combobox is basically a Popup when the toggle button is pressed.
You could implement your own popup or you could have a look at the template of the ComboBox. Here is a link to ComboBox template

How to get rid of double selection thing in ListView (XAML)

I have a ListView and I bind to an ObservableCollection<Folder> and when I hover over a ListViewItem, there is a second selection thing appearing underneath (or ontop of) the item text which prevents me from being able to "activate" the selected item because it doesn't appear to be receiving my click.
As you can probably see, the structure is:
ListView > ItemTemplate > DataTemplate > ListViewItem. But I'm guessing I have that double-selection thing because there are basically 2 "item templates" (DataTemplate and ItemTemplate). But if I get rid of DataTemplate, it throws a runtime error. If I get rid of ItemTemplate, it throws an error. I can't win. How do I get rid of this thing?
Update:
This gives me the desired effect:
<StackPanel x:Name="folderContainer" HorizontalAlignment="Left" VerticalAlignment="Stretch" Width="175" Background="Khaki" Margin="0, 18, 0, 0">
<ListView x:Name="folderList" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" ItemsSource="{Binding Folder}" BorderBrush="{x:Null}" BorderThickness="0">
<ListView.ItemTemplate>
<DataTemplate>
<TextBlock x:Name="folderItem" Text="{Binding Name}" />
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackPanel>

With the ListViewItem you where including a specialized wrapper primarily used the ListView to contain unknown item(s) presented by the binding of the ItemsSource when there is default template used. It helps to show that unknown item on the screen, its the purpose of the ListViewItem. For example if someone bound a list of strings, the strings have no xaml style on hover, hence there needs to be a container control to achieve all things graphical in those situations.
Why the two Shadows?
The actual ListViewItem is at its heart (or actually its property), a content control containing what I surmise you had was a textbox control. That is now two controls thanks to the DataTemplate you provided.
Hence you had a wrapper, with a content containing a texbox control. So there are two things which take up space, one is the ListViewItem and the other is the textbox. By hovering over each item, each's style kicked off to show the padding of the control as a selectable region in the Zorder fashion whereas both are seen.
Nothing more nothing less.
Since you knew what is to go into the content control, there was no need to use the ListViewItem wrapper, it was redundant, and you used the actual textbox; hence with only it's style to show the padding of the single control on hover.

ListBox horizontal scroll-to method C# WP 8.0

I'm trying to use in my application an input-selected index to scroll a ListBox (horizontally scrollable). I've found on MSDN and on this own site the method ScrollIntoView but it doesn't work and on the ListBox Class page it has been written to be compatible with WP 7.0, 7.1. So, this is a snapshot of my code...
scrolling.ScrollIntoView(scrolling.Items[20]);
where scrolling is my ListBox and the 20th item is the one I want to be selected and visualized.
PS: I've already tried to use the selectedIndex way but it is still not working!
This is a xaml of my ListBox (put in the Layout Grid) which have referencies to templates written in the App.xaml document.
<ListBox x:Name="scrolling" Grid.Column="0" ScrollViewer.ManipulationMode ="Control" ScrollViewer.VerticalScrollBarVisibility="Disabled" ScrollViewer.HorizontalScrollBarVisibility="Visible">
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
</ListBox>
edit: I found that calling the function by a button makes the all whole stuff work, but how to initialize everything at the start?

I used in my solution first updated UI and then called ScrollIntoView it works fine:
scrolling.UpdateLayout();
scrolling.ScrollIntoView(scrolling.Items[20]);

Get Clicked Item in GridView within SemanticZoom

I have a very basic SemanticZoom implementation within my Windows 8 app. This app has the following xaml:
<SemanticZoom x:Name="semanticZoom" VerticalAlignment="Stretch" IsZoomedInViewActive="False">
<SemanticZoom.ZoomedOutView>
<GridView x:Name="myGridView" ItemsSource="{Binding Source={StaticResource orderViewSource}}" ScrollViewer.IsHorizontalScrollChainingEnabled="False" SelectionMode="None" IsItemClickEnabled="True" ItemClick="orderGridView_ItemClick">
</GridView>
</SemanticZoom.ZoomedOutView>
...
</SemanticZoom>
Oddly, the orderGridView_ItemClick event never fires when I click an item. I've heard that the semantic zoom control catches it, and doesn't bubble it down. If that's the case though, there should still be a way for me to see which item was selected. How do I determine what item an user clicks from the ZoomedOutView within a SemanticZoom control?
Thank you!