How to do drag and drop with elements in ItemsControl?
I turn AllowDrop and CanDrag in true but nothing works.
<ItemsControl Visibility="Collapsed" ItemsSource="{Binding MyItems}" Margin="0,3,0,0" Padding="5,0,0,0" CanDrag="True" AllowDrop="True">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<ItemsWrapGrid MaximumRowsOrColumns="3" Orientation="Horizontal"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<Border CanDrag="True" AllowDrop="True" Background="{Binding Color}" Height="{Binding Height}" Width="{Binding Width}"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
This does not work on the phone. I know about listView and GridView. I do not need Reorder Mode. I need a table where you can drag and drop items, and replace each other. 1 > 5 and 5 > 1 places. Swap elements of the first to the fifth, and the fifth on the first!
I have thought of doing something like CanvasTabelView. I do not know whether it is real!
Related
My MVVM WPF application uses Linq2SQL for using SQL Server Express. I noticed after populating the database with real data I get some big delays for the UI to update and thought is was my query/ grouping strategy. But, while some of the data fills take more than 100ms, rarely do they take more than 200ms but I'm seeing a lag of up to 3 seconds on the window refresh. EDIT FOR BREVITY:
I was wrapping my ItemsControl in a ScrollViewer:
<ScrollViewer VerticalScrollBarVisibility="Auto" Grid.Column="0" Grid.Row="3" Grid.ColumnSpan="2" ScrollChanged="ScrollViewer_ScrollChanged">
<ItemsControl x:Name="DivisionItems" ItemsSource="{Binding oObsByDiv}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<uc:ucObservationsHeader/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</ScrollViewer>
But after some hints from below and reading up on Virtualization I now use a ListBox like so:
<ListBox x:Name="DivisionItems" Grid.Column="0" Grid.Row="3" Grid.ColumnSpan="2"
ItemsSource="{Binding oObsByDiv}"
ScrollViewer.CanContentScroll="True"
VirtualizingStackPanel.ScrollUnit="Pixel">
<ListBox.Template>
<ControlTemplate>
<ScrollViewer VirtualizingStackPanel.IsVirtualizing="True"
VirtualizingStackPanel.VirtualizationMode="Recycling">
<ItemsPresenter/>
</ScrollViewer>
</ControlTemplate>
</ListBox.Template>
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<VirtualizingStackPanel/>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemTemplate>
<DataTemplate>
<uc:ucObservationsHeader/>
</DataTemplate>
</ListBox.ItemTemplate>
The user control used for the Items in that template then calls another user control that I'm wrapping in another ListBox in a very similar manner:
<ListBox ItemsSource="{Binding lObs}" Grid.Row="1" Grid.Column="1"
HorizontalContentAlignment="Stretch" ScrollViewer.HorizontalScrollBarVisibility="Disabled"
ScrollViewer.CanContentScroll="True"
VirtualizingStackPanel.ScrollUnit="Pixel">
<ListBox.Template>
<ControlTemplate>
<ScrollViewer VirtualizingStackPanel.IsVirtualizing="True"
VirtualizingStackPanel.VirtualizationMode="Recycling">
<ItemsPresenter/>
</ScrollViewer>
</ControlTemplate>
</ListBox.Template>
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<VirtualizingStackPanel/>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemTemplate>
<DataTemplate>
<uc:ucObservationsView/>
</DataTemplate>
</ListBox.ItemTemplate>
But the multiple second lag still exists. The outer user control is instantiated 15 times, and the inner one has on average 15 items each. What is it that is breaking virtualization in this case? I keep stripping out the ScrollUnit and CanContentScroll in one or both places, as well as the HorizontalContentAlignement and the HorizontalScrollBar visibility, but those just affect the look without seeming to be the cause for breaking virtualization.
Am using listbox control in WPF its display listbox item in row wise but I want to display in column wise ( Something like bootstrap grid)
XMAL
<ListBox x:Name="lb_items">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Margin="10 0 0 0">
<Image Source="{Binding ImageSource}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Am binding Listbox from code behind
lb_items.ItemsSource = modules.ToList();
Try this one.
<ListBox x:Name="lb_items">
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel IsItemsHost="True" />
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Margin="10 0 0 0">
<Image Source="{Binding ImageSource}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
ListBox has property called ItemsPanel, which determines how items are rendered.
Somewhere in application resource create different ItemsPanelTemplate, so you can easily reuse it:
<ItemsPanelTemplate x:Key="WrapPanelTemplate">
<WrapPanel />
</ItemsPanelTemplate>
<ItemsPanelTemplate x:Key="HorizontalStackPanelTemplate">
<StackPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
then you can easily use it:
<ListBox ItemsPanel="{StaticResource HorizontalStackPanelTemplate}">...
<ItemControl ItemsPanel="{StaticResource WrapPanelTemplate}">...
always put such assets into application resources in order to make the code for your views clean and readable.
Extra Tip:
Here is animated WrapPanel, that animates items, when you resize window or an item is inserted to the list:
<ItemsPanelTemplate x:Key="FluidWrapPanel">
<WrapPanel>
<i:Interaction.Behaviors>
<ei:FluidMoveBehavior AppliesTo="Children" Duration="0:0:0.5">
<ei:FluidMoveBehavior.EaseY>
<SineEase EasingMode="EaseInOut" />
</ei:FluidMoveBehavior.EaseY>
<ei:FluidMoveBehavior.EaseX>
<CubicEase EasingMode="EaseInOut" />
</ei:FluidMoveBehavior.EaseX>
</ei:FluidMoveBehavior>
</i:Interaction.Behaviors>
</WrapPanel>
</ItemsPanelTemplate>
dont forget to include these xml namespaces:
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions"
I am working on c# xaml using silverlight and i am bit confused about the hierarchy of this xaml code:
<UserControl.Resources>
<this:MyValueConverter x:Key="TabConverter"/>
</UserControl.Resources>
<Grid x:Name="LayoutRoot" Background="Green">
<ItemsControl ItemsSource="{Binding Path=TabList, Mode=OneWay}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<Canvas></Canvas>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<Border Width="150" Background="red" Height="100" Canvas.Left="{Binding TabList, Mode=TwoWay, Converter={StaticResource TabConverter}}" Canvas.Top="100" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Grid>
When i run it gives a big green color window(sorry if technical names are not correct), whereas it should also show red color somewhere in same window as it has Border Width="150" Background="red" .Could some one please explain me what this code is doing ?
ItemsControl really just binds to a list and applies a datatemplate (border with background red) for each item in the list. As for the reason you're only seeing green, well there's probably nothing in the TabList property on your viewmodel. That way, nothing in the items template renders, and all you see is green.
You'll need to make sure that TabList is bound correctly (it exists on your datacontext, whether that's a view model or not) and that it has items in it.
Here's a simpler version of what you may want to accomplish:
<Grid x:Name="LayoutRoot" Background="Green">
<ItemsControl ItemsSource="{Binding Path=TabList, Mode=OneWay}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal" />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<Border Width="150" Background="red" Height="100" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Grid>
I'd like to display basically a matrix of buttons, the number of buttons change in runtime.
My problem is that I want them to be next to each other to fill up all the space I give them. I thought WrapPanel is the perfect way to do that but it puts the buttons under each other and I have no idea how to solve it.
<Grid>
<WrapPanel Width="250" Height="50" Orientation="Horizontal" Margin="543,442,73,162" >
<ItemsControl ItemsSource="{Binding States}" >
<ItemsControl.ItemTemplate>
<DataTemplate >
<Button Width="50" Height="25" Content="{Binding StateName}" Padding="0" ></Button>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</WrapPanel>...</Grid>
States is a list of Items that contains a name and a ID number. If i want to add or remove buttons I modify the list. So the buttons appear but in vertical order and they go beyond the limits of the WrapPanel so if it is not big enough only some appears. They only use 50 width from the 250 and more then the 50 height. In this case if I put 5 buttons in it only shows 2 of them.
Don't wrap ItemsControl inside WrapPanel. Instead set it as ItemsPanel of ItemsControl.
<ItemsControl ItemsSource="{Binding States}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Button Width="50" Height="25" Content="{Binding StateName}"
Padding="0"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>
I am trying to do an interface in WPF where a list of item is displayed, taking as little vertical space as possible:
My instinct was to use an ItemsControl to bind my list, and to put the UI for each item into a WrapPanel. Unfortunately by default, each item starts at a new line regardless of the window's size. Adding a StackPanel with Orientation="Horizontal" makes all items in a single line, regardless of the size...
<!--<ScrollViewer Grid.Row="0" Grid.Column="0"
VerticalScrollBarVisibility="Auto">-->
<ItemsControl Margin="0,4" ItemsSource="{Binding Path=Watchers}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"></StackPanel>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.Resources>
<DataTemplate DataType="{x:Type Core:Watcher}">
<WrapPanel Orientation="Horizontal">
<TextBlock Margin="0,2" Text="{Binding Path=Name}"
Width="250px" />
<TextBox Text="{Binding Path=Value, Mode=OneWay}"
Width="300px">
</TextBox>
</WrapPanel>
</DataTemplate>
</ItemsControl.Resources>
</ItemsControl>
<!--</ScrollViewer>-->
Any pointers?
Bonus point: Where should I add a ScrollViewer in order to have the behavior shown in my mockup?
Thanks a lot!
The WrapPanel has, as well as the StackPanel, an Orientation property, which defaults to Vertical. So your list should wrap (assuming you have enough space at hand) if your ItemsPanelTemplate looks like this:
<ItemsPanelTemplate>
<WrapPanel Orientation="Horizontal" />
</ItemsPanelTemplate>
About the ScrollViewer:
The desired behavior should be achieved by defining it like follows (not tested though, and I omitted all for this example unnecessary stuff):
<ScrollViewer HorizontalAlignment="Stretch">
<ItemsControl MinWidth="550" Width="{Binding ActualWidth, Mode=OneWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ScrollViewer}}}" />
</ScrollViewer>
I think you want the WrapPanel in the ItemsPanel and the StackPanel in the ItemTemplate.
why not use the WrapPanel as ItemsPanelTemplate?
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
as long as the items have space to the left they would be arranged horizontal.