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Menu Item Binding WPF Issue

I have a problem with Menu Item Command Binding. I have used MVVM pattern
When I use right click, the menu appears. But when I click on the menu item doesn't work. Do you know why? Thanks
Here is the XAML:
<UserControl x:Class="PlotView.ViewModel.PlotViewControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:oxy="http://oxyplot.org/wpf"
mc:Ignorable="d"
xmlns:diagnostics="clr-namespace:System.Diagnostics;assembly=WindowsBase"
d:DesignHeight="400" d:DesignWidth="600"
x:Name="theViewName">
<UserControl.Resources>
</UserControl.Resources>
<GroupBox Name="GB" Header="Graphs" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" BorderThickness="0">
<ListView Name="PlotLista" SelectedIndex="{Binding SelectedValue}" ItemsSource="{Binding PlotModelList}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" >
<ListView.ItemTemplate>
<DataTemplate>
<oxy:Plot MinHeight="260" Height="Auto" IsRendering="True" FontStyle="Normal" FontFamily="Arial" FontSize="8" VerticalContentAlignment="Top" HorizontalContentAlignment="Left" Width="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type UserControl}}, Path=ActualWidth}" Model="{Binding }">
<oxy:Plot.ContextMenu>
<ContextMenu>
<MenuItem Header="Export to PNG" Command="{Binding DataContext.SavePNG, ElementName=theViewName}"/>
</ContextMenu>
</oxy:Plot.ContextMenu>
</oxy:Plot>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</GroupBox>
</UserControl>
Here are a small portion of ViewModel:
#region Fields
private readonly DelegateCommand _menuClick=new DelegateCommand(this.MenuItemClick);
#endregion
#region Command
public ICommand SavePNG
{
get { return this._menuClick; }
}
#endregion
private void MenuItemClick()
{
// some code here
}
Error:
System.Windows.Data Error: 40 : BindingExpression path error:
'SavePNG' property not found on 'object' ''PlotModel'
(HashCode=15385318)'. BindingExpression:Path=SavePNG;
DataItem='PlotModel' (HashCode=15385318); target element is 'MenuItem'
(Name=''); target property is 'Command' (type 'ICommand')

Your binding is trying to find SavePNG on your Item, not your ViewModel.
Instead, give your view an x:Name, or a Name, and use the following binding instead:
{Binding DataContext.SavePNG, ElementName=theViewName}

Assuming that SaveCommand is on the same ViewModel which contains your collection.
ContextMenus are a little different in wpf as they are not part of the visual tree of the control. As such they cannot 'see' any elements by relative source or by elementnames.
A little cheat is to use the PlacementTarget property and get the datacontext with that. Change your ListView to below to make it work. Notice the tag property on the ListView and the DataContext property on the ContextMenu.
<ListView Name="PlotLista" SelectedIndex="{Binding SelectedValue}" ItemsSource="{Binding PlotModelList}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Tag="{Binding DataContext,ElementName=theViewName}">
<ListView.ItemTemplate>
<DataTemplate>
<oxy:Plot MinHeight="260" Height="Auto" IsRendering="True" FontStyle="Normal" FontFamily="Arial" FontSize="8" VerticalContentAlignment="Top" HorizontalContentAlignment="Left" Width="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type UserControl}}, Path=ActualWidth}" Model="{Binding }">
<oxy:Plot.ContextMenu>
<ContextMenu DataContext="{Binding PlacementTarget.Tag, RelativeSource={RelativeSource Self}}">
<MenuItem Header="Export to PNG" Command="{Binding SavePNG}"/>
</ContextMenu>
</oxy:Plot.ContextMenu>
</oxy:Plot>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>

This wasn't written in visual studio so please check the syntax:
<ListView Tag="{Binding Path=DataContext,ElementName=theViewName}">
<ListView.ItemTemplate>
<DataTemplate>
<oxy:Plot Tag="{Binding Path=Tag,RelativeSource={RelativeSource AncestorType=ListView}">
<oxy:Plot.ContextMenu>
<ContextMenu DataContext="{Binding PlacementTarget.Tag, RelativeSource={RelativeSource Self}}">
<MenuItem Command="{Binding SavePNG}"/>
</ContextMenu>
</oxy:Plot.ContextMenu>
</oxy:Plot>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>

Dynamic stack of ComboBoxes trying to add new items

I have an Items control bound to a observable collection of TaskActivity objects.
<ItemsControl ItemsSource="{Binding TasksActivities, UpdateSourceTrigger=PropertyChanged}" Margin="20, 0, 20, 20">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid Margin="2, 0, 2, 0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width= "*" />
<ColumnDefinition Width= "*" />
<ColumnDefinition Width= "*" />
<ColumnDefinition Width= "70"/>
</Grid.ColumnDefinitions>
<ComboBox x:Name="test" IsEditable="True" ItemsSource="{Binding Source={StaticResource Locator}, Path=Main.AvailableActivities, Mode=TwoWay}" SelectedValue="{Binding ActivityId}" Text="{Binding Name, UpdateSourceTrigger=LostFocus}" SelectedValuePath="Key" DisplayMemberPath="Value" HorizontalAlignment="Stretch" Grid.Column="0">
</ComboBox>
<TextBox Text="{Binding Length}" Grid.Column="1" />
<TextBox Text="{Binding Comment}" Grid.Column="2" />
<Button Height="24" Content="Remove" HorizontalAlignment="Right" Margin="10, 0, 10, 0" Style="{StaticResource LinkButton}" Grid.Column="3">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<cmd:EventToCommand Command="{Binding Source={StaticResource Locator}, Path=Main.DeleteActivityCommand, Mode=OneWay}" CommandParameter="{Binding Name}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</Button>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
When a value is typed in the combobox that is doesn't exist and focus is lost, I want to have a prompt appear asking if they want to add add that value to the AvailableActivities list (which is just a Dictionary). Right now the border just goes red, and while it does update the "Name" property of the object inside the OC, it's not real because it can't set the ActivityId since it doesn't actually exist in the list of AvailableActivities.
I've tried an EventToCommand for SelectionChanged and LostFocus, but when a new value is entered, the value I'm returned is 'null' so I can't add it.
Normally I could just bind the text value to a property on the VM and just do it all there, but since it's a property inside a ObservableCollection of TaskActivity objects I'm not sure that's possible.
Any suggestions for achieving this functionality?

First make the ComboBox.Text a two-way binding so that the view model property gets updated:
Text="{Binding Path=Name, UpdateSourceTrigger=LostFocus, Mode=TwoWay}"
With that in place, add a command to the ComboBox's LostFocus event:
<ComboBox>
<i:Interaction.Triggers>
<i:EventTrigger EventName="LostFocus">
<cmd:EventToCommand Command="{Binding Source={StaticResource Locator},
Path=Main.AddNewActivityCommand}"
CommandParameter="{Binding ElementName=test,Path=Text}"
/>
</i:EventTrigger>
</i:Interaction.Triggers>
</ComboBox>
And finally, the "AddNewActivityCommand" should just add the new item (in the "Name" property) to the "AvailableActivities" collection.

How can i bind a button in listviewitem to a Command in ViewModel in Winrt

I have a NavigateToAccountsCommand RelayCommand property in the ViewModel. When I bind the same to a button on the page anywhere outside the ListView the command binding is working. However as soon as I move this to a ListView's DataTemplate its not working.
I have tried changing the binding from NavigateToAccountsCommand to DataContext.NavigateToAccountsCommand still not working.
Appreciate your help...
<Page
x:Class="FinancePRO.App.Views.AccountsView"
DataContext="{Binding AccountsViewModel, Source={StaticResource MainViewModelLocator}}"
mc:Ignorable="d">
<Grid>
<!--**This one is working**-->
<Button Command="{Binding NavigateToAccountsCommand}" >
<!--**This one is not working**-->
<ListView ItemsSource="{Binding AllAccounts}" >
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel HorizontalAlignment="Stretch">
<TextBlock Text="{Binding AccountName}"/>
<Button Command="{Binding NavigateToAccountsCommand}">
</Button>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>

When you are inside the DataTemplate of the ListView, your data context is the current item of the ListView's ItemsSource. As there is nothing called "NavigateToAccountsCommand" property within your AllAcounts' each individual element, binding isn't working.
To fix that, you will need to reference something from the outside of DataTemplate; following should work. It changes the binding to reference the root Grid's DataContext which should have the property NavigateToAccountsCommand accessible. To reference the grid, you have to add Name attribute, and then use ElementName binding.
<Grid Name="Root">
<!--**This one is working**-->
<Button Command="{Binding NavigateToAccountsCommand}" >
<!--**This one is not working**-->
<ListView ItemsSource="{Binding AllAccounts}" >
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel HorizontalAlignment="Stretch">
<TextBlock Text="{Binding AccountName}"/>
<Button Command"{Binding ElementName=Root, Path=DataContext.NavigateToAccountsCommand}">
</Button>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</Grid>

You can use
<Button x:Name="cmdTabItemCloseButton"
Style="{StaticResource TabItemCloseButtonStyle}"
Grid.Column="1" Margin="15,0,0,0"
Command="{Binding RelativeSource=
{RelativeSource FindAncestor,
AncestorType={x:Type ListView}},
Path=DataContext.NavigateToAccountsCommand}"
CommandParameter="{Binding}"/>

I had a similar problem (Win RT) which I solved by just using:
<GridView
x:Name="itemGridView"
ItemClick="ItemView_ItemClick"
IsItemClickEnabled="True"/>
and then in the Page class:
private void ItemView_ItemClick(object sender, ItemClickEventArgs e)
{
//e is the object being clicked
}

WPF ListBox selection

I have a problem with extended selection in ListBox. Let's say I have a ListBox with 10 items and I'm selecting first 5 of them using Shift button. The SelectionChanged event is fired with 5 items. After that I want to select 3 items from those 5, again with Shift button pressed, but SelectionChanged event is not fired. How can I react to the second selection of items, when I'm selecting 3 of those 5 previously selected ones?

can you show the xaml code as well I would like to see what your binding looks like
it should looks something like this.. but I can't be certain unless I see your code
In Command binding you have used binding which has relative source binding...
consider making these changes in binding
1) using list box as Ancestortype
2) While binding use Path=DataContext.SelectionChangedCommand otherwise it will take list box as datacontext.
<catel:EventToCommand Command="{Binding Path=DataContext.SelectionChangedCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ListBox}}}" DisableAssociatedObjectOnCannotExecute="False" PassEventArgsToCommand="True" />
here is an example of what the XAML would look like for ListBoxItem Template
<Grid>
<StackPanel Orientation="Horizontal">
<Label Width="180">Field1</Label>
<ListBox Height="200"
IsSynchronizedWithCurrentItem="True"
ItemsSource="{Binding List1, Mode=OneWay}"
Name="listBox1"
SelectionMode="Single"
Width="300">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Width="290">
<TextBlock Width="90" Text="{Binding}"></TextBlock>
<ComboBox Width="180" ItemsSource="{Binding DataContext.List2, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}" DisplayMemberPath="Field1">
<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectionChanged">
<catel:EventToCommand Command="{Binding Path=DataContext.SelectionChangedCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ListBox}}}" DisableAssociatedObjectOnCannotExecute="False" PassEventArgsToCommand="True" />
</i:EventTrigger>
</i:Interaction.Triggers>
</ComboBox>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>

Unable to access viewmodel properties from inside Listvew.Resources

I'm trying to bind the SelectedItem to a View. But the view is not able to access the viewmodel when it is inside the Resources block.
When the datacontext is re-assigned to the children, the binding works for textblocks but not for UserControl (NoteView)
Am I missing any Binding?
PFB revised(entire) code and inline comments.
<UserControl x:Class="Konduva.View.NoteSearchView"
<!-- other namespaces here -->
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
DataContext="{Binding NoteSearch, Source={StaticResource Locator}}">
<Grid>
<ListView ItemsSource="{Binding Notes}"
SelectedItem="{Binding SelectedNote}">
<ListView.Resources>
<DataTemplate DataType="{x:Type vm:NoteViewModel}">
<DockPanel>
<TextBlock Text="{Binding Title}" />
<Popup Placement="Right"
PlacementTarget="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=ListViewItem}}"
IsOpen="{Binding (ListViewItem.IsSelected), RelativeSource={RelativeSource FindAncestor, AncestorType=ListViewItem}}"
DataContext="{Binding Path=DataContext, RelativeSource={RelativeSource AncestorType={x:Type ListView}}}">
<StackPanel>
<!-- This is working --> <TextBlock Text="{Binding SelectedNote.Title}" />
<!-- This is not working --> <v:NoteView DataContext="{Binding SelectedNote}" />
</StackPanel>
</Popup>
</DockPanel>
</DataTemplate>
</ListView.Resources>
</ListView>
</Grid>
</UserControl>
NoteView:
<Grid>
<TextBlock Text="{Binding Title}" /> // This Text is not displayed
</Grid>

Update 3
Since you're using MvvmLight: in NoteView, try changing
DataContext="{Binding Note, Source={StaticResource Locator}}"
to
<UserControl.Style>
<Style TargetType="UserControl">
<Setter Property="DataContext" Value="{Binding Note, Source={StaticResource Locator}}"/>
</Style>
</UserControl.Style>
Update 2
Encountered a similar problem a few minutes ago which I didn't fully understand so I'll throw in the same solution here to see if it helps. What happends if you change it to this?
<v:NoteView DataContext="{Binding RelativeSource={RelativeSource AncestorType={x:Type Popup}},
Path=DataContext.SelectedNote}"/>
Update
I'm unable to reproduce this. Try adding this in your NoteView constructor. Do you reach DataContextChangedHandler when you change the selection in the ListView?
public NoteView()
{
InitializeComponent();
DependencyPropertyDescriptor dpd =
DependencyPropertyDescriptor.FromProperty(UserControl.DataContextProperty,
typeof(UserControl));
if (dpd != null)
{
dpd.AddValueChanged(this, new EventHandler(DataContextChangedHandler));
}
}
void DataContextChangedHandler(object sender, EventArgs e)
{
MessageBox.Show("DataContext Changed: " + DataContext);
}
First answer
Your DockPanel will get the NoteViewModel as a DataContext and not the ListView and since this DataContext is inherited by all Childs every child will end up with a NoteViewModel as DataContext. To use the ListView as a DataContext for the Popup you can do this. I'm not sure what the DataContext Binding for the StackPanel does though, so I might be missing something here..
<DataTemplate DataType="{x:Type vm:NoteViewModel}">
<DockPanel>
<TextBlock Text="{Binding Title}" />
<Popup Placement="Right"
PlacementTarget="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=ListViewItem}}"
IsOpen="{Binding (ListViewItem.IsSelected), RelativeSource={RelativeSource FindAncestor, AncestorType=ListViewItem}}"
DataContext="{Binding Path=DataContext, RelativeSource={RelativeSource AncestorType={x:Type ListView}}}">
<StackPanel>
<TextBlock Text="{Binding SelectedNote.Title}" />
<StackPanel>
<v:NoteView DataContext="{Binding SelectedNote}"/>
</StackPanel>
</StackPanel>
</Popup>
</DockPanel>
</DataTemplate>

Instead of inserting a NoteView directly and binding the DataContext, use a ContentPresenter:
<ContentPresenter Content="{Binding SelectedNote}>
<ContentPresenter.ContentTemplate>
<DataTemplate>
<v:NoteView />
</DataTemplate>
</ContentPresenter.ContentTemplate>
</ContentPresenter>