I am trying to bind a VM method as a command in MenuItem. Though menu is displays correctly the function never get called.I expecting the MenuCommand Method to be get called from the command binding.
Xaml
<Menu.ItemTemplate>
<HierarchicalDataTemplate ItemsSource="{Binding SubMenu}">
<TextBlock Text="{Binding Name}">
<TextBlock.InputBindings>
<MouseBinding Command="{Binding MenuCommand}" MouseAction="LeftClick" />
</TextBlock.InputBindings>
</TextBlock>
</HierarchicalDataTemplate>
</Menu.ItemTemplate>
ViewModel
public class MenuViewModel : ViewModelBase
{
public ObservableCollection<Menu> Menu { get; set; }
public RelayCommand MenuCommand { get; set; }
public void Load()
{
Menu = new ObservableCollection<Menu> {
new Menu
{
Name = "File",
SubMenu = new List<Menu>
{
new Menu { Name = "New" },
new Menu { Name = "Open" },
new Menu { Name = "Save" }
}
}};
MenuCommand = new RelayCommand(MenuExecution);
}
public void MenuExecution(object item)
{
MessageBox.Show("Hello");
}
}
Thanks #GK & #Mark I am able to bind the command successfully by below Xaml
<Menu ItemsSource="{Binding Menu}" >
<Menu.ItemContainerStyle>
<Style TargetType="{x:Type MenuItem}" >
<Setter Property="Command" Value="{Binding ElementName=level1Lister, Path=DataContext.MenuCommand}" />
<Setter Property="CommandParameter" Value="{Binding RelativeSource={RelativeSource Self}}"/>
</Style>
</Menu.ItemContainerStyle>
<Menu.ItemTemplate>
<HierarchicalDataTemplate ItemsSource="{Binding Path=SubMenu}">
<TextBlock Text="{Binding Name}"/>
</HierarchicalDataTemplate>
</Menu.ItemTemplate>
</Menu>
Related
I need to present a WPF GridView where one column is a Combobox, The user can select one value from the list or enter a new value so I set the IsComboBoxEditable to true but the problem is that if the user types a value that is not in the ItemsSource the Text is blank when the Combobox looses the focus.
Note : I don't want, when a new value is typed , this value to be
added to the ItemsSource. I only need to save it's string value in row
that bounded to it.
I also need DropDownOpened event, to populate it's ItemsSource.
Here is my code:
<telerik:GridViewDataColumn Header="Description">
<telerik:GridViewDataColumn.CellTemplate>
<DataTemplate>
<telerik:RadComboBox IsEditable="True" ItemsSource="{Binding Descriptions}" Text="{Binding Description1,Mode=TwoWay}" DropDownOpened="descriptionRadComboBox_DropDownOpened"/>
</DataTemplate>
</telerik:GridViewDataColumn.CellTemplate>
</telerik:GridViewDataColumn>
Description1 is string property, and Descriptions is List of string that populate in runtime.(When DropDownOpened Event occurred)
Like you mentioned, your goal is, simply, to "Editable ComboBox".
(And, of course, you don't want to add new Item to ItemsSource)
<telerik:GridViewDataColumn UniqueName="description1" Header="Description">
<telerik:GridViewDataColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding Description1}"></TextBlock>
</DataTemplate>
</telerik:GridViewDataColumn.CellTemplate>
<telerik:GridViewDataColumn.CellEditTemplate>
<DataTemplate>
<telerik:RadComboBox Name="SLStandardDescriptionsRadComboBox" IsEditable="True"
ItemsSource="{Binding DataContext.SLStandardDescriptions, RelativeSource={RelativeSource AncestorType={x:Type UserControl}}}"
DisplayMemberPath="SLStandardDescriptionTitle" DropDownOpened="Description_DropDownOpened">
</telerik:RadComboBox>
</DataTemplate>
</telerik:GridViewDataColumn.CellEditTemplate>
</telerik:GridViewDataColumn>
Codebehinde :
private void RadGridView_CellEditEnded(object sender, GridViewCellEditEndedEventArgs e)
{
if (e.Cell.Column.UniqueName == "description1")
{
RadComboBox combo = e.Cell.ChildrenOfType<RadComboBox>().FirstOrDefault();
if (combo != null)
{
List<Description> comboItems = combo.ItemsSource as List<Description>;
string textEntered = e.Cell.ChildrenOfType<RadComboBox>().First().Text;
bool result = comboItems.Contains(comboItems.Where(x => x.DescriptionTitle == textEntered).FirstOrDefault());
if (!result)
{
comboItems.Add(new Description { DescriptionTitle = textEntered });
combo.SelectedItem = new Description { DescriptionTitle = textEntered };
}
if (_viewModel.AccDocumentItem != null)
{
if (e.Cell.Column.UniqueName == "description1")
_viewModel.AccDocumentItem.Description1 = textEntered;
}
}
}
}
Here is the solution for .net DataGrid control:
<DataGrid ItemsSource="{Binding Path=Items}" AutoGenerateColumns="False">
<DataGrid.Columns>
<DataGridTextColumn Binding="{Binding Path=Title}" ></DataGridTextColumn>
<DataGridComboBoxColumn SelectedValueBinding="{Binding ComboItem.ID}" DisplayMemberPath="ComboTitle" SelectedValuePath="ID">
<DataGridComboBoxColumn.ElementStyle>
<Style TargetType="{x:Type ComboBox}">
<Setter Property="ItemsSource" Value="{Binding Path=DataContext.ComboItems, RelativeSource={RelativeSource AncestorType={x:Type Window}}}" />
</Style>
</DataGridComboBoxColumn.ElementStyle>
<DataGridComboBoxColumn.EditingElementStyle>
<Style TargetType="{x:Type ComboBox}">
<Setter Property="ItemsSource" Value="{Binding Path=DataContext.ComboItems, RelativeSource={RelativeSource AncestorType={x:Type Window}}}" />
<Setter Property="IsEditable" Value="True" />
</Style>
</DataGridComboBoxColumn.EditingElementStyle>
</DataGridComboBoxColumn>
</DataGrid.Columns>
</DataGrid>
Surely you can do this using Telerik DataGrid control as well.
And here is my ViewModel:
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
DataContext = this;
ComboItems = new ObservableCollection<ComboItem>()
{
new ComboItem(){ID=1,ComboTitle="ComboItem1"},
new ComboItem(){ID=2,ComboTitle="ComboItem2"},
new ComboItem(){ID=3,ComboTitle="ComboItem3"}
};
Items = new ObservableCollection<Item>()
{
new Item(){ID=1,Title="Item1",ComboItem=ComboItems[0]},
new Item(){ID=2,Title="Item2",ComboItem=ComboItems[1]},
new Item(){ID=3,Title="Item3",ComboItem=ComboItems[2]}
};
}
public ObservableCollection<Item> Items { get; set; }
public ObservableCollection<ComboItem> ComboItems { get; set; }
}
public class Item
{
public int ID { get; set; }
public string Title { get; set; }
public ComboItem ComboItem { get; set; }
}
public class ComboItem
{
public int ID { get; set; }
public string ComboTitle { get; set; }
}
I'm trying to bind a single MenuItem's ItemsSource to a ReadOnlyCollection<string>located in the ViewModel. I've read that the ContextMenu is not under the main Visual tree so i can't bind it directly, but any method i try doesn't work. I have the code snippet please let me know what am i doing wrong.
<Window>
…
<DockPanel>
<!-- Task bar Icon -->
<tb:TaskbarIcon x:Name="AppNotifyIcon"
DataContext="{Binding Path=DataContext, RelativeSource={RelativeSource AncestorType={x:Type Window}}}"
ToolTipText="{Binding Source={StaticResource LocalizedStrings}, Path=Strings.MainTitle}">
<tb:TaskbarIcon.ContextMenu>
<ContextMenu DataContext="{Binding Path=PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}">
<MenuItem Header="{Binding Source={StaticResource LocalizedStrings}, Path=Strings.NotifyIconOpen}" Click="MenuItem_Open_Click"/>
<MenuItem Header="Technologies" ItemsSource="{Binding to the ReadOnlyCollection of string in ViewModel}">
<MenuItem.ItemContainerStyle>
<Style>
<Setter Property="MenuItem.Command" Value="{Binding <!--Command in ViewModel-->, RelativeSource={RelativeSource AncestorType=Window}}"/>
<Setter Property="MenuItem.CommandParameter" Value="{Binding}"/> <!—Binding to the menuItem Header item -->
</Style>
</MenuItem.ItemContainerStyle>
</MenuItem>
<MenuItem Header="{Binding Source={StaticResource LocalizedStrings}, Path=Strings.NotifyIconExit}" Click="MenuItem_Exit_Click"/>
</ContextMenu>
</tb:TaskbarIcon.ContextMenu>
</tb:TaskbarIcon>
…
</DockPanel>
I am trying to bind the second MenuItem's ItemsSource and inside it's ItemContainerStyle i want to bind the command and the commandParameter.
**Update: ** i'm using hardcodet's TaskbarIcon for wpf, if it matters.
Thanks
Try check this out:
1. XAML Code:
<DataGrid x:Name="SelectDataGrid"
ItemsSource="{Binding Persons}" HorizontalAlignment="Left" CellEditEnding="SelectDataGrid_OnCellEditEnding"
VerticalAlignment="Top" AutoGenerateColumns="False" Loaded="SelectDataGrid_OnLoaded">
<DataGrid.ContextMenu>
<ContextMenu>
<MenuItem Header="Technologies" ItemsSource="{Binding MenuItems}">
<MenuItem.ItemContainerStyle>
<Style TargetType="MenuItem">
<Setter Property="Command" Value="{Binding Command}"/>
<Setter Property="Header" Value="{Binding Content}"/>
<Setter Property="CommandParameter" Value="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ContextMenu}}, Path=DataContext}"/>
</Style>
</MenuItem.ItemContainerStyle>
</MenuItem>
</ContextMenu>
</DataGrid.ContextMenu>
<DataGrid.Columns>
<DataGridTemplateColumn>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Button Command="{Binding HelloCommand}"></Button>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn></DataGrid>
2. DataContext of the context menu is the same as datagrid and window.
3. Inside the DataContext put the next code:
private void Init()
{
MenuItems = new ObservableCollection<MenuItemObject>(new List<MenuItemObject>
{
new MenuItemObject {Command = new RelayCommand<object>(Execute), Content = "A"},
new MenuItemObject {Command = new RelayCommand<object>(Execute), Content = "B"},
new MenuItemObject {Command = new RelayCommand<object>(Execute), Content = "C"},
new MenuItemObject {Command = new RelayCommand<object>(Execute), Content = "D"},
});
}
public ObservableCollection<MenuItemObject> MenuItems { get; set; }
private void Execute(object o)
{
}
4. MenuItemsObject model code:
public class MenuItemObject:BaseObservableObject
{
private ICommand _command;
private string _content;
public ICommand Command
{
get { return _command; }
set
{
_command = value;
OnPropertyChanged();
}
}
public string Content
{
get { return _content; }
set
{
_content = value;
OnPropertyChanged();
}
}
}
5. MVVM parts implementation:
public class BaseObservableObject : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
var handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
protected virtual void OnPropertyChanged<T>(Expression<Func<T>> raiser)
{
var propName = ((MemberExpression)raiser.Body).Member.Name;
OnPropertyChanged(propName);
}
protected bool Set<T>(ref T field, T value, [CallerMemberName] string name = null)
{
if (!EqualityComparer<T>.Default.Equals(field, value))
{
field = value;
OnPropertyChanged(name);
return true;
}
return false;
}
}
public class RelayCommand<T> : ICommand
{
readonly Action<T> _execute;
readonly Func<T, bool> _canExecute;
public event EventHandler CanExecuteChanged;
public RelayCommand(Action<T> execute, Func<T, bool> canExecute = null)
{
_execute = execute;
_canExecute = canExecute;
}
public void RefreshCommand()
{
var cec = CanExecuteChanged;
if (cec != null)
cec(this, EventArgs.Empty);
}
public bool CanExecute(object parameter)
{
if (_canExecute == null) return true;
return _canExecute((T)parameter);
}
public void Execute(object parameter)
{
_execute((T)parameter);
}
}
public class RelayCommand : RelayCommand<object>
{
public RelayCommand(Action execute, Func<bool> canExecute = null)
: base(_ => execute(),
_ => canExecute == null || canExecute())
{
}
}
Call to Init method to generate toy menu item's collection DataContext.
An Execute is the method called when some menu item is pressed.
That is all. I'will be glad to help if there will be problems with the code.
Regards,
Ok, I have found the problem thanks to Ilan's suggestion in the comments of using snoop utility.
I saw that in the visual tree, the ContextMenu didn't have its PlacementTarget to point to its parent, the TaskbarIcon (Weird..), but it had an Attached Property called TaskbarIcon.ParentTaskbarIcon from the TaskbarIcon, so i binded the ContextMenu's DataContext to the TaskbarIcon.ParentTaskbarIcon.Tag and that fixed it all.
<Window>
...
<DockPanel>
<!-- Task bar Icon -->
<tb:TaskbarIcon x:Name="AppNotifyIcon"
IconSource="pack://application:,,,/Icons/HwServerIcon.ico"
Tag="{Binding Path=DataContext, RelativeSource={RelativeSource AncestorType={x:Type Window}}}"
ToolTipText="{Binding Tag, RelativeSource={RelativeSource Self}}"><!--{Binding Source={StaticResource LocalizedStrings}, Path=Strings.MainTitle}-->
<tb:TaskbarIcon.ContextMenu>
<ContextMenu DataContext="{Binding Path=(tb:TaskbarIcon.ParentTaskbarIcon).Tag, RelativeSource={RelativeSource Self}}">
<MenuItem Header="{Binding Source={StaticResource LocalizedStrings}, Path=Strings.NotifyIconOpen}" Click="MenuItem_Open_Click"/>
<MenuItem Header="Technologies" ItemsSource="{Binding TechnologiesNames}">
<MenuItem.ItemContainerStyle>
<Style>
<Setter Property="MenuItem.Command" Value="{Binding DataContext.OpenTechnology, RelativeSource={RelativeSource AncestorType={x:Type ContextMenu}}}"/>
<Setter Property="MenuItem.CommandParameter" Value="{Binding}"/>
</Style>
</MenuItem.ItemContainerStyle>
</MenuItem>
<MenuItem Header="{Binding Source={StaticResource LocalizedStrings}, Path=Strings.NotifyIconExit}" Click="MenuItem_Exit_Click"/>
</ContextMenu>
</tb:TaskbarIcon.ContextMenu>
</tb:TaskbarIcon>
So, the TaskbarIcon's Tag is pointing the Window's DataContext and the ContextMenu's DataContext is pointing the Taskbar's attached property ParentTaskbarIcon.Tag and from now every binding is performed like it was under the window in the visual tree.
For a context menu in a ListBox I add my DataContext to the parent control's tag, and find it in a relative source binding to the placement target. There are many questions on SO regarding this though, and some of those may address more specific instances.
<ListBox ItemsSource="{Binding ItemList}"
SelectedItem="{Binding SelectedItem}"
Tag="{Binding}">
<ListBox.ContextMenu>
<ContextMenu DataContext="{Binding PlacementTarget.Tag, RelativeSource={RelativeSource Self}}">
<MenuItem Header="Delete"
Command="{Binding Path=DeleteCommand}"/>
</ContextMenu>
</ListBox.ContextMenu>
</ListBox>
So for your example specifically:
<tb:TaskbarIcon x:Name="AppNotifyIcon"
DataContext="{Binding Path=DataContext, RelativeSource={RelativeSource AncestorType={x:Type Window}}}"
ToolTipText="{Binding Source={StaticResource LocalizedStrings}, Path=Strings.MainTitle}"
Tag="{Binding}">
<tb:TaskbarIcon.ContextMenu>
<ContextMenu DataContext="{Binding Path=PlacementTarget.Tag, RelativeSource={RelativeSource Self}}">
<MenuItem Header="{Binding Source={StaticResource LocalizedStrings}, Path=Strings.NotifyIconOpen}" Click="MenuItem_Open_Click"/>
<MenuItem Header="Technologies" ItemsSource="{Binding TechnologyList}">
<MenuItem.ItemContainerStyle>
<Style>
<Setter Property="MenuItem.Command" Value="{Binding VmCommand}"/>
<Setter Property="MenuItem.CommandParameter" Value="{Binding}"/>
</Style>
</MenuItem.ItemContainerStyle>
</MenuItem>
<MenuItem Header="{Binding Source={StaticResource LocalizedStrings}, Path=Strings.NotifyIconExit}" Click="MenuItem_Exit_Click"/>
</ContextMenu>
</tb:TaskbarIcon.ContextMenu>
Of course your bindings will probably vary, but from here you should at least have the DataContext set, and go from there.
In my TreeView I use two differnt classes for binding. For example, I have a Group what can have ChildGroup and can have Items.
Example code of this classes:
using System.Collections.Generic;
using System.Collections.ObjectModel;
namespace WpfApplication1
{
public class Group
{
public Group(string name)
{
Name = name;
items = new ObservableCollection<Item>();
groups = new ObservableCollection<Group>();
}
public string Name { get;
set;
}
private ObservableCollection<Item> items;
private ObservableCollection<Group> groups;
public ObservableCollection<Item> Items
{
get { return items; }
}
public ObservableCollection<Group> Groups
{
get { return groups; }
}
public IEnumerable<object> AllItems
{
get
{
foreach (var group in groups)
{
yield return group;
}
foreach (var item in items)
{
yield return item;
}
}
}
}
public class Item
{
public Item(string name)
{
ItemName = name;
}
public string ItemName
{
get;
set;
}
}
}
To bind it to TreeView I use following template
<Grid>
<TreeView Name="treeView">
<TreeView.Resources>
<HierarchicalDataTemplate DataType="{x:Type WpfApplication1:Group}"
ItemsSource="{Binding AllItems}">
<TextBlock Text="{Binding Name}"/>
</HierarchicalDataTemplate>
<DataTemplate DataType="{x:Type WpfApplication1:Item}">
<TextBlock Text="{Binding ItemName}" FontStyle="Italic"/>
</DataTemplate>
</TreeView.Resources>
</TreeView>
</Grid>
It is easy.
The problem is that I need to change ItemTemplate when Is selected. And I need to change only then Item class selected.
I can do it if only one class use for binding. It also easy using Style and Trigger, like this:
<TreeView Name="treeView1" Grid.Column="1">
<TreeView.Resources>
<HierarchicalDataTemplate DataType="{x:Type WpfApplication1:Group}"
ItemsSource="{Binding AllItems}"
x:Key="groupTemplate">
<TextBlock Text="{Binding Name}"/>
</HierarchicalDataTemplate>
<HierarchicalDataTemplate DataType="{x:Type WpfApplication1:Group}"
ItemsSource="{Binding AllItems}"
x:Key="selectedGroupTemplate">
<TextBlock Text="{Binding Name}" FontStyle="Italic" FontWeight="Bold" FontSize="14"/>
</HierarchicalDataTemplate>
</TreeView.Resources>
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<Setter Property="HeaderTemplate" Value="{StaticResource groupTemplate}"/>
<Style.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter Property="HeaderTemplate" Value="{StaticResource selectedGroupTemplate}"/>
</Trigger>
</Style.Triggers>
</Style>
</TreeView.ItemContainerStyle>
</TreeView>
But I have a trouble for multiclass binding.
How can I change SelectedItem template then multiclass binding using? Any ideas?
My code behind sample:
using System.Collections.ObjectModel;
using System.Windows;
namespace WpfApplication1
{
/// <summary>
/// Interaction logic for Window2.xaml
/// </summary>
public partial class Window2 : Window
{
private ObservableCollection<Group> _groups;
public ObservableCollection<Group> Groups
{
get { return _groups; }
}
public Window2()
{
InitializeComponent();
InitGroups();
treeView.ItemsSource = _groups;
treeView1.ItemsSource = _groups;
}
private void InitGroups()
{
_groups = new ObservableCollection<Group>();
Group group1 = new Group("Group1");
group1.Groups.Add(new Group("Group1.1"));
group1.Groups.Add(new Group("Group1.2"));
group1.Groups.Add(new Group("Group1.3"));
group1.Items.Add(new Item("Item1.1"));
group1.Items.Add(new Item("Item1.2"));
group1.Groups[1].Items.Add(new Item("Item1.2.1"));
group1.Groups[1].Items.Add(new Item("Item1.2.2"));
_groups.Add(group1);
Group group2 = new Group("Group2");
group2.Groups.Add(new Group("Group2.1"));
group2.Groups.Add(new Group("Group2.2"));
group2.Items.Add(new Item("Item2.1"));
group2.Groups[0].Items.Add(new Item("Item2.1.1"));
group2.Groups[0].Items.Add(new Item("Item2.1.1"));
_groups.Add(group2);
}
}
}
Result
Now I think to use TreeView.HeaderTemplateSelector, but may be exists way to use only xaml.
Thanks.
There are a number of ways to acheive your desired result. If you are sure that your DataTemplate will only be used in TreeViewItem objects, then the easiest is simply to bind directly to the TreeViewItem.IsSelected property and then react to the change in your DataTemplate:
<DataTemplate DataType="{x:Type WpfApplication1:Item}">
<TextBlock Text="{Binding ItemName}">
<TextBlock.Style>
<Style>
<Style.Triggers>
<DataTrigger Binding="{Binding IsSelected, RelativeSource=
{RelativeSource FindAncestor, AncestorType={x:Type TreeViewItem}}, FallbackValue=False}"
Value="True">
<Setter Property="TextBlock.FontStyle" Value="Italic" />
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
</TextBlock>
</DataTemplate>
In my application, I have a view (ListView) and a view model. Inside view model, I have 2 properties: first is a list of items, and the second is a command. I want to display items (from first property) inside ListView. In addition, I want to have for each one a context menu, where clicking on it will activate a command (from second property).
Here is a code of my view model:
public class ViewModel
{
public IEnumerable Items
{
get
{
return ...; //returns a collection of items
}
}
public ICommand MyCommand //this is a command, I want to be able execute from context menu of each item
{
get
{
return new DelegateCommand(new Action<object>(delegate(object parameter)
{
//here code of the execution
}
), new Predicate<object>(delegate(object parameter)
{
//here code of "can execute"
}));
}
}
Now the XAML part:
<ListView ItemsSource="{Binding Items}">
<ListView.Resources>
<commanding:CommandReference x:Key="myCommand" Command="{Binding MyCommand}"/>
</ListView.Resources>
<ListView.ItemTemplate>
<DataTemplate>
<TextBlock
Text="{Binding Name}"
/>
</DataTemplate>
</ListView.ItemTemplate>
<ListView.ItemContainerStyle>
<Style TargetType="{x:Type ListViewItem}">
<Setter Property="ContextMenu">
<Setter.Value>
<ContextMenu>
<MenuItem
Header="Remove from workspace"
Command="{StaticResource myCommand}"
CommandParameter="HERE I WANT TO PASS THE DATA CONTEXT OF THE ListViewItem"
/>
</ContextMenu>
</Setter.Value>
</Setter>
</Style>
</ListView.ItemContainerStyle>
</ListView>
The problem: until I actually opening context menu, the PlacementTarget of the context menu is null. I need somehow to receive data context of the clicked ListViewItem into "CanExecute" of the command, BEFORE the command being called - and I truly wish to make everything in the XAML, without handling any callbacks in code behind.
Thank you in advance.
If you are looking for ListViewItem's DataContext you can do this:
CommandParameter="{Binding}"
Edit - Here is what I tried:
public partial class MainWindow : Window
{
private ObservableCollection<Person> list = new ObservableCollection<Person>();
public MainWindow()
{
InitializeComponent();
list.Add(new Person() { Name = "Test 1"});
list.Add(new Person() { Name = "Test 2"});
list.Add(new Person() { Name = "Test £"});
list.Add(new Person() { Name = "Test 4"});
this.DataContext = this;
}
public static ICommand MyCommand //this is a command, I want to be able execute from context menu of each item
{
get
{
return new DelegateCommand<Person>(
a => Console.WriteLine(a.Name),
a => true);
}
}
public ObservableCollection<Person> Items
{
get
{
return this.list;
}
}
}
public class Person
{
public string Name { get; set; }
}
And the xaml:
<Window x:Class="ListView1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:ListView1="clr-namespace:ListView1" Title="MainWindow" Height="350" Width="525">
<Grid>
<ListView ItemsSource="{Binding Items}">
<ListView.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}" />
</DataTemplate>
</ListView.ItemTemplate>
<ListView.ItemContainerStyle>
<Style TargetType="{x:Type ListViewItem}">
<Setter Property="ContextMenu">
<Setter.Value>
<ContextMenu>
<MenuItem Header="Remove from workspace" Command="{x:Static ListView1:MainWindow.MyCommand}" CommandParameter="{Binding}" />
</ContextMenu>
</Setter.Value>
</Setter>
</Style>
</ListView.ItemContainerStyle>
</ListView>
</Grid>
</Window>
Assume the following class definitions.
public enum ContentType { Playlist, Audio, Video, Picture }
public interface IDataProvider
{
string Name
{
get;
}
}
public class ProviderList : List<IDataProvider>
{
}
public class MainViewModel
{
public Dictionary<ContentType, ProviderList> ProvidersDictionary;
public MainViewModel()
{
if (IsInDesignMode)
{
// Code runs in Blend --> create design time data.
}
else
{
// Code runs "for real"
this.ProvidersDictionary = new Dictionary<ContentType, ProviderList>();
ProviderList providerList = new ProviderList();
providerList.Add(new DataProvider());
this.ProvidersDictionary.Add(ContentType.Audio, providerList);
providerList = new ProviderList(providerList);
providerList.Add(new DataProvider());
this.ProvidersDictionary.Add(ContentType.Video, providerList);
}
}
}
So, this ProvidersDictionary property is bound to Window context menu as follows:
<Window.ContextMenu>
<ContextMenu ItemsSource="{Binding ProvidersDictionary}">
<ContextMenu.ItemTemplate>
<HierarchicalDataTemplate ItemsSource="{Binding Value}">
<TextBlock Margin="1" Text="{Binding Key}" Height="20"/>
<HierarchicalDataTemplate.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}" />
</DataTemplate>
</HierarchicalDataTemplate.ItemTemplate>
</HierarchicalDataTemplate>
</ContextMenu.ItemTemplate>
</ContextMenu>
</Window.ContextMenu>
The question is: how to make ICommand databinding for the DataProvider menu item click and to retrieve data type (enum type) and data provider (IDataProvider interface) within the command' Execute method.
Update
I want to have some command class to be bound to MenuItems like:
class DataProviderMenuSelectCommand : ICommand
{
#region ICommand Members
public void Execute(object parameter)
{
ContentTypeProviderPair contentProviderPair = parameter as ContentTypeProviderPair;
if (contentProviderPair != null)
{
// contentProviderPair.Type property - ContentType
// contentProviderPair.Provider property - IProvider
}
}
}
MainViewModel will expose instance of this command class as a property.
The problem has been solved:
<UserControl x:Class="DataProvidersView"
...
<ContextMenu.ItemContainerStyle>
<Style TargetType="{x:Type MenuItem}">
<Setter Property="Command" Value="{Binding Path=DataContext.DataProviderSwitchCommand,
RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type vw:DataProvidersView}}}" />
<Setter Property="CommandParameter">
<Setter.Value>
<MultiBinding>
<Binding Path="DataContext.Key"
RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type ItemsControl}}" />
<Binding />
</MultiBinding>
</Setter.Value>
</Setter>
</Style>
</ContextMenu.ItemContainerStyle>
</UserControl>