Develop Reference

Binding checkbox ischecked inside listbox(WPF)

I'm trying to bind checkbox ischecked value. but whenever I click multiple checkbox, only last item is get selected.
This is my xaml.
<ListBox x:Name="EntryBox" ItemsSource="{Binding SourceCollection}"
SelectedItem="{Binding SelectedCheckbox}" SelectionMode="Multiple"
Grid.Column="0" Grid.Row="0" >
<ListBox.ItemTemplate>
<DataTemplate>
<ListBoxItem IsSelected="{Binding Selected}">
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding Selected}"/>
</StackPanel>
</ListBoxItem>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
My viewmodel
public class MytViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private ObservableCollection<Item> _socketEntryCollection;
public MyViewModel()
{
_socketEntryCollection = new ObservableCollection<Item>();
}
private ListCollectionView _sourceCollection;
public ListCollectionView SourceCollection
{
get { return _sourceCollection; }
set
{
_sourceCollection = value;
NotifyPropertyChanged(nameof(SourceCollection));
}
}
private Item _selectedCheckbox;
public Item SelectedCheckbox
{
get
{
return _selectedCheckbox;
}
set
{
_selectedCheckbox = value;
NotifyPropertyChanged(nameof(SelectedCheckbox));
}
}
public class Item : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private bool _selected;
public Item()
{
_selected = false;
}
public bool Selected
{
get { return _selected; }
set
{
if(_selected != value)
{
_selected = value;
NotifyPropertyChanged(nameof(Selected));
}
}
}
private void NotifyPropertyChanged(string Obj)
{
if (PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(Obj));
}
}
In my code behind,
private MyViewModel _BVM;
public BulkTest()
{
InitializeComponent();
_BVM = new MyViewModel();
}
foreach (MyViewModel.Item i in _BVM.SourceCollection)
{
if (i.Selected)
{
}
}
When I try to retrieve selected items, it only gives me only the last item I checked even though I checked multiple.
I would like to get every item that I checked.
How can I do that?

Maintain checkbox state while the app is running in WPF

I'm working in MVVM, WPF and I have a popup; inside this popup is a listbox and inside the listbox I have a checkbox. The problem is: if I uncheck an item from the list box and click outside, popup disappears; if a I click again the checkbox is reseted at its initial value (all the items become checked).
So, how can I maintain the state of the popup set and stop its resetting while the app is running ? Can I do this through XAML ?
here is the code:
public class CheckedListItem<T> : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private bool isChecked = false;
private T item;
public CheckedListItem()
{ }
public CheckedListItem(T item, bool isChecked)
{
this.item = item;
this.isChecked = isChecked;
}
public T Item
{
get { return item; }
set
{
item = value;
if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Item"));
}
}
public bool IsChecked
{
get { return isChecked; }
set
{
isChecked = value;
if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("IsChecked"));
}
}
}
the viewModel:
private void OnApplyFiltersCommandRaised(object obj)
{
if (FilterElement.Contains("ClassView"))
{
switch (FilterElement)
{
case "buttonClassViewClassFilter":
FilteredClassViewItems.Clear();
FilteredFieldViewItems.Clear();
foreach (var filterItem in FilterItems)
{
if (filterItem.IsChecked == true)
{
FilteredClassViewItems.Add(classViewItems.First(c => c.ClassName == filterItem.Item));
FilteredFieldViewItems.Add(fieldViewItems.First(c => c.ClassName == filterItem.Item));
}
}
break;
...
public ObservableCollection<CheckedListItem<string>> FilterItems
{
get
{
return filterItems;
}
set
{
filterItems = value;
SetPropertyChanged("FilterItems");
}
}
the XAML part:
<ListBox x:Name="listBoxPopupContent"
Height="250"
ItemsSource="{Binding FilterItems}"
BorderThickness="0"
ScrollViewer.VerticalScrollBarVisibility="Auto">
<ListBox.Resources>
<Style TargetType="{x:Type ListBoxItem}">
<Setter Property="FontSize" Value="8" />
<Setter Property="IsSelected" Value="{Binding IsChecked, Mode=TwoWay}" />
</Style>
</ListBox.Resources>
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox IsChecked="{Binding IsChecked}"
Content="{Binding Item}"
Command="{Binding DataContext.ApplyFiltersCommand,
RelativeSource={RelativeSource FindAncestor,
AncestorType={x:Type ListBox}}}"
CommandParameter="{Binding IsChecked,
RelativeSource={RelativeSource Self},
Mode=OneWay}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Thanks in advance !

If you want to keep the state, you can just create a new view that will contain your listbox. Then your popup will be
<Popup>
<views:MyListBoxview>
</Popup>
where views is the path where wpf can find MyListBoxview.
This is an example of how you can do MyListBoxView. First of all, add a new usercontrol to your project. Then you create:
<ListBox ItemSource = {Binding MyCollectionOfItem}>
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox IsChecked = {Binding IsItemChecked} Content = {Binding Name}/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
You will need to assign to this view a viewmodel that will of course implement INotifyPropertyChanged and that will have these this class defined inside it (also this class will implement INotifyPropertyChanged)
public class MyItem : INotifyPropertyChanged
{
public void SetPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
public event PropertyChangedEventHandler PropertyChanged;
private bool isItemChecked = false;
public bool IsItemChecked
{
get { return isItemChecked; }
set
{
isItemChecked = value;
SetPropertyChanged("IsItemChecked");
}
}
private string name ;
public string Name
{
get { return Name; }
set
{
name = value;
SetPropertyChanged("Name");
}
}
}
finally, the viewmodel that will represent the state of the popup will have inside this property
private ObservableCollection<MyItem> myCollectionOfItem = new ObservableCollection<MyItem>();
public ObservableCollection<MyItem> MyCollectionOfItem
{
get { return myCollectionOfItem; }
set
{
myCollectionOfItem = value;
SetPropertyChanged("MyCollectionOfItem");
}
}
I usually handle this kind of problem modelling properly the object that i need to bind to my controls in WPF

Enable,Disable button upon check/uncheck of checkboxes

I have a view that contains a list box with various items in button form and a checkbox for each of the button. XAML:
<ListBox.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<CheckBox x:Name="CheckFavorite"
Width="Auto"
Height="Auto"
AutomationProperties.AutomationId="AID_FavoritesCheck"
IsChecked="{Binding Path=IsChecked,
Mode=TwoWay}"
Visibility="{Binding IsFavoriteConfiguredAndInDA,
Converter={StaticResource boolToVisibility}}"
Checked="OnContentChanged"
Unchecked="OnContentChanged"/>
<Button Grid.Column="1"
Width="240"
HorizontalContentAlignment="Left"
VerticalContentAlignment="Center"
AutomationProperties.AutomationId="AID_BtnLaunchFavorite"
Command="{Binding Path=LaunchFavorite}"
Content="{Binding Path=ModuleDisplayName}"
Cursor="Hand"
FontSize="{StaticResource UxLevel_5}"
Padding="24 12 2 12"
ToolTip="{Binding Path=ModuleDisplayName}" />
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
I have another button called "Launch". Its basic functionality is to launch the tasks as per the selection in the above listbox items so that multiple tasks can be launched.Button XAML:
<Button Name="btnLaunch"
Width="80"
Height="25"
HorizontalAlignment="Left"
AutomationProperties.AutomationId="AUI_BtnLaunchForFavorite"
Command="{Binding LaunchCommand}"
Style="{StaticResource LaunchButtonStyle}"
Visibility="{Binding IsRIAMode,
Converter={StaticResource boolToVisibilityInverter}}">
Issue:
I want to enable/disable this launch button if atleast one item is selected and disable otherwise.How can i achieve? Pls help with some code snippets.
UPDATE:
Here is the launch command:
public ICommand LaunchCommand { get; private set; }
LaunchCommand = new DelegateCommand<object>(OnLaunch);
internal void OnLaunch(object sender)
{
var nFavItemToLaunchCount = Favorites.Count(favItem => favItem.IsChecked);
if (!IsSessionLimitReached(nFavItemToLaunchCount))
{
foreach (FavoriteItemViewModel favoriteItem in Favorites)
{
if (favoriteItem.IsChecked)
{
favoriteItem.LaunchFavorite.Execute(sender);
}
}
}
}
UPDATE 2:
I made the changes as per Krishna's comment:
LaunchCommand = new DelegateCommand<object>(OnLaunch,ToggleLaunch);
private bool ToggleLaunch(object obj)
{
if (Favorites.Count(i => i.IsChecked)!=0) //Favorites is the itemsource
{
return true;
}
return false;
}
Still the launch button is shown disabled always even when item is selected/checked.
UPDATE 3
After Krishna's further comment, i changed the implementation of the property IsChecked and also implemented INotifyPropertyChanged in the viewmodel.Still no luck!
public class FavoriteItemViewModel:INotifyPropertyChanged
{
public bool IsChecked
{
get
{
return m_IsChecked;
}
set
{
m_IsChecked = value;
OnPropertyChanged("IsChecked");
}
}
/// <summary>
/// Handler for property change
/// </summary>
/// <param name="propertyName">Name of property</param>
protected void OnPropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
There is another viewmodel "FavoriteContainerViewModel" that holds the collection of "FavoriteItemViewModel" and also implements INotifyPropertyChanged. This container view model is the place where i added the code mentioned in UPDATE 2
UPDATE 4:
Implementation of favorites:
public class FavoriteContainerViewModel : ViewModelBase, IModuleView
{
private readonly ObservableCollection<FavoriteItemViewModel> m_Favorites = new ObservableCollection<FavoriteItemViewModel>();
public ObservableCollection<FavoriteItemViewModel> Favorites
{
get { return m_Favorites; }
}
public FavoriteContainerViewModel()
{
LaunchCommand = new DelegateCommand<object>(OnLaunch, ToggleLaunch);
OnLoad();
}
private bool ToggleLaunch(object obj)
{
if (Favorites.Count(i => i.IsChecked) != 0)
{
return true;
}
return false;
//return true;
}
}
Note:ViewModelBase implements INotifyPropertyChanged
Update 5:
Problem now resolved using event based model. Implemented following:
FavoriteViewModel.cs
public event EventHandler ItemChecked;
public bool IsChecked
{
get
{
return m_IsChecked;
}
set
{
m_IsChecked = value;
if (ItemChecked != null)
{
ItemChecked(this, new EventArgs());
}
}
}
FavoriteItemContainerViewModel.cs
private void SubscribeFavoriteItemEvents(FavoriteItemViewModel favorite)
{
favorite.ItemChecked += ToggleLaunchButton;
}
private bool m_IsLaunchEnabled;
public bool IsLaunchEnabled
{
get
{
return m_IsLaunchEnabled;
}
set
{
m_IsLaunchEnabled = value;
OnPropertyChanged("IsLaunchEnabled");
}
}
Property IsLaunchEnabled is binded to the button to enable/disable.

You can enable/disable the Button based on the CheckBox.IsChecked property:
<Button Name="btnLaunch"
Width="80"
Height="25"
HorizontalAlignment="Left"
AutomationProperties.AutomationId="AUI_BtnLaunchForFavorite"
Command="{Binding LaunchCommand}"
Style="{StaticResource LaunchButtonStyle}"
Visibility="{Binding IsRIAMode,
Converter={StaticResource boolToVisibilityInverter}}"
IsEnabled="{Binding ElementName=CheckFavorite, Path=IsChecked}">

I am guessing the launch button is outside the listbox and user clicks it once the checkboxes are checked.
In that case, you need to add a condition in the 'CanExecute' part of your ICommand (LaunchCommand)
Lets assume your ICommand implementation in the constructor is something like
LaunchCommand = new RelayCommand(launchMethod);
private void launchMethod(object obj)
{
//do some work here
}
Now add canExecute part to your command by changing the initialisation
LaunchCommand = new DelegateCommand<object>(OnLaunch,checkCheckboxes);
and add this method
private bool checkCheckboxes(object obj)
{
//YourList is your itemsource
return YourList.Where(i=>i.IsChecked).Any();
}
Just change the above method to suit your needs
Update change your IsChecked property to below
private bool isChecked;
public bool IsChecked
{
get { return isChecked; }
set
{
isChecked = value;
OnPropertyChanged("IsChecked");
}
}

if (checkbox1.Checked && !checkbox2.Checked)
{
button1.Enable = true
}
else if (!checkbox1.Checked && checkbox2.Checked)
{
button1.Enable = false
}

Add additional control to ObervableCollection

I'm really new to WPF so apologies in adavnced if this is an obvious question. I have a simple Checkbox in XAML as
<ListBox ScrollViewer.VerticalScrollBarVisibility="Auto"
ItemsSource="{Binding Selections}" >
<ListBox.ItemTemplate>
<DataTemplate>
<Grid >
<CheckBox IsChecked="{Binding IsChecked}"
Content="{Binding Path=Item.SelectionName}" />
</Grid >
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Simplified code behind to allow bindings and INotifyPropertyChanged is:
public ObservableCollection<CheckedListItem<Selection>> Selections { get; set; }
public class Selection
{
public String SelectionName { get; set; }
}
Selections = new ObservableCollection<CheckedListItem<Selection>>();
Selections.Add(new CheckedListItem<Selection>(new Selection()
{ SelectionName = "SomeName" }, isChecked: true));
public class CheckedListItem<T> : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private bool isChecked;
private T item;
public CheckedListItem()
{ }
public CheckedListItem(T item, bool isChecked = false)
{
this.item = item;
this.isChecked = isChecked;
}
public T Item
{
get { return item; }
set
{
item = value;
if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Item"));
}
}
public bool IsChecked
{
get { return isChecked; }
set
{
isChecked = value;
if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("IsChecked"));
}
}
}
I now need to add an additional TextBox associated with each Checkbox, so in XAML I have
<ListBox ScrollViewer.VerticalScrollBarVisibility="Auto"
ItemsSource="{Binding Selections}" Margin="12,22,12,94">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid >
<CheckBox IsChecked="{Binding IsChecked}"
Content="{Binding Path=Item.SelectionName}" />
<<TextBox />
</Grid >
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
I'm a bit stumped how to include this as part of the ObservableCollection and set it up the binding on both the CheckBox and associated TextBox? Both are being added together using Selections.Add(new CheckedListItem<Selection>(new Selection()
{ SelectionName = "SomeName" }, isChecked: true)); which is causing me some confusion.
EDIT: Added full code
public partial class SelectionSettingWindow : Window
{
public ObservableCollection<CheckedListItem<Selection>> Selections { get; set; }
public class Selection
{
public String SelectionName { get; set; }
public string SelectionTextField { get; set; }
}
public SelectionSettingWindow()
{
InitializeComponent();
Selections = new ObservableCollection<CheckedListItem<Selection>>();
string fg = #"Item1,true,TExtbox1text:Item2,true,TExtbox2text:Item3,false,TExtbox3text"; //Test String
string[] splitSelections = fg.Split(':');
foreach (string item in splitSelections)
{
string[] spSelectionSetting = item.Split(',');
bool bchecked = bool.Parse(spSelectionSetting[1].ToString());
string tbText = spSelectionSetting[2].ToString();
Selections.Add(new CheckedListItem<Selection>(new Selection()
{ SelectionName = spSelectionSetting[0].ToString(),
SelectionTextField = bText }, isChecked: bchecked));
}
DataContext = this;
}
public class CheckedListItem<T> : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private bool isChecked;
private T item;
private string textField;
public CheckedListItem()
{ }
public CheckedListItem(T item, bool isChecked = false)
{
this.item = item;
this.isChecked = isChecked;
}
public T Item
{
get { return item; }
set
{
item = value;
if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("Item"));
}
}
public bool IsChecked
{
get { return isChecked; }
set
{
isChecked = value;
if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("IsChecked"));
}
}
public string TextField
{
get { return textField; }
set
{
textField = value;
if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs("TextField"));
}
}
}
}

<ListBox ScrollViewer.VerticalScrollBarVisibility="Auto"
ItemsSource="{Binding Selections}" Margin="12,22,12,94">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<CheckBox IsChecked="{Binding IsChecked, Mode=TwoWay}"
Content="{Binding Path=Item.SelectionName}" />
<TextBox Text="{Binding Item.SelectionTextField, Mode=TwoWay}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
replace SelectionTextField above with whatever the field is that needs to be edited using the textbox on your Selection class.
Note that I changed the <Grid> to a <StackPanel> So they wouldn't appear on top of eachother and changed the bindings to TwoWay so the changes are reflected in the model.
Make sure your Selection class implements INotifyPropertyChanged (ObservableCollection updates the UI when things get added to/removed from the collection, it doesn't know anything about notifying when it's content's properties change so they need to do that on their own)
Implementing INotifyPropertyChanged on many classes can be cumbersome. I find implementing a base class useful for this. I've got this along with an extra reflection helper for raise property changed available here and a snippet I've made available. It's silverlight but it should work fine for WPF. Using the code I've provided via download you can simply type proprpc and hit tab and visual studio will stub in a property that notifies on change. Some explanation is in one of my old blog posts here and gives credit for where I based the code and snippet from.

How can I handle multiple CheckBoxes in the MVVM pattern?

Binding checkbox in WPF is common issue, but I am still not finding example code which is easy to follow for beginners. I have check box list in WPF to select favorite sports’ name. The number of checkboxes is static in my case. Can anyone show me how to implement ViewModel for this issue?
FavoriteSportsView.xaml:
<StackPanel Height="50" HorizontalAlignment="Left" VerticalAlignment="Top"
Width="150">
<CheckBox IsChecked="{Binding IsChecked, Mode=TwoWay}"
Command="{Binding Path=SportsResponseCommand}"
CommandParameter="Football"
Content="Football"
Margin="5" />
<CheckBox IsChecked="{Binding IsChecked, Mode=TwoWay}"
Command="{Binding Path=SportsResponseCommand}"
CommandParameter="Hockey"
Content="Hockey"
Margin="5" />
<CheckBox IsChecked="{Binding IsChecked, Mode=TwoWay}"
Command="{Binding Path=SportsResponseCommand}"
CommandParameter="Golf"
Content="Golf"
Margin="5" />
</StackPanel>
FavoriteSportsViewModel.cs
public class FavoriteSportsViewModel.cs {
//Since I am using the same IsChecked in all check box options, I found all check
//boxes gets either checked or unchecked when I just check or uncheck one option.
//How do i resolve this issue? I don't think i need seprate IsChecked for each
//check box option.
private bool _isChecked;
public bool IsChecked{
get {
return _isChecked;
}
set { if (value != _isChecked)
_isChecked = value;
this.OnPropertyChanged("IsChecked");
}
}
//How do i detect parameter in this method?
private ICommand _sportsResponseCommand;
public ICommand SportsResponseCommand
{
get
{
if (_sportsResponseCommand== null)
_sportsResponseCommand= new
RelayCommand(a => DoCollectSelectedGames(), p => true);
return _sportsResponseCommand;
}
set
{
_sportsResponseCommand= value;
}
}
private void DoCollectSelectedGames(){
//Here i push all selected games in an array
}
public abstract class ViewModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
I'm not sure how to do the following in above ViewModel:
1. How do I implement single method to handle all my options?
2. how do I detect each one of the checkboxes to see whether checked or not
3. How do i utlize CommandParameter?
4. How do i implement SportsResponseCommand correctly

Your view model should look something like this:
public class MyViewModel : INotifyPropertyChanged
{
//INotifyPropertyChanged implementation
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
if (this.PropertyChanged != null)
this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
//bindable property
private bool _football;
public bool Football
{
get { return _football; }
set
{
if (value != _football)
{
_football = value;
this.OnPropertyChanged("Football");
}
}
}
//... and the same for Golf and Hockey
}
Then you associate your view model with the view by setting the DataContext property (this will most likely be in the Window or UserControl code behind, though there are a lot of ways to achieve this).
Finally, update your bindings so that they look like:
<CheckBox IsChecked="{Binding Football, Mode=TwoWay}"
Content="Football"
Margin="5" />
<CheckBox IsChecked="{Binding Golf, Mode=TwoWay}"
Content="Football"
Margin="5" />
As a final comment, you shouldn't really need to bind the Command property - you can just write whatever code you need to run in the property setter on the view model.

I highly recommend you to read this http://msdn.microsoft.com/en-us/magazine/dd419663.aspx
I describe a solution below I tried to not modify your XAML code but it is not the only way (or the best approach) but contains all necessary elements!
At first step you need your model I call it Model_Sport
public class Model_Sport : INotifyPropertyChanged
{
#region Constructor
public Model_Sport(string name, ICommand command)
{
Name = name;
SportsResponseCommand = command;
}
#endregion
static readonly PropertyChangedEventArgs _NameEventArgs = new PropertyChangedEventArgs("Name");
private string _Name = null;
public string Name
{
get { return _Name; }
set
{
_Name = value;
OnPropertyChanged(_NameEventArgs);
}
}
static readonly PropertyChangedEventArgs _SportsResponseCommandEventArgs = new PropertyChangedEventArgs("SportsResponseCommand");
private ICommand _SportsResponseCommand = null;
public ICommand SportsResponseCommand
{
get { return _SportsResponseCommand; }
set
{
_SportsResponseCommand = value;
OnPropertyChanged(_SportsResponseCommandEventArgs);
}
}
static readonly PropertyChangedEventArgs _IsCheckedEventArgs = new PropertyChangedEventArgs("IsChecked");
private bool _IsChecked = false;
public bool IsChecked
{
get { return _IsChecked; }
set
{
_IsChecked = value;
OnPropertyChanged(_IsCheckedEventArgs);
}
}
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
protected void OnPropertyChanged(PropertyChangedEventArgs eventArgs)
{
if (PropertyChanged != null)
{
PropertyChanged(this, eventArgs);
}
}
#endregion
}
Now you need a way to delegate your command “SportsResponseCommand”, DelegateCommand object will help you to do that
public class DelegateCommand : ICommand
{
private readonly Action<object> _ExecuteMethod;
private readonly Func< object, bool> _CanExecuteMethod;
#region Constructors
public DelegateCommand(Action<object>executeMethod, Func<object, bool> canExecuteMethod)
{
if (null == executeMethod)
{
throw new ArgumentNullException("executeMethod", "Delegate Command Delegates Cannot Be Null");
}
_ExecuteMethod = executeMethod;
_CanExecuteMethod = canExecuteMethod;
}
public DelegateCommand(Action<object>executeMethod) : this(executeMethod, null) { }
#endregion
#region Methods
public bool CanExecute(object parameter)
{
if (_CanExecuteMethod == null) return true;
return _CanExecuteMethod(parameter);
}
public void Execute(object parameter)
{
if (_ExecuteMethod == null) return;
_ExecuteMethod(parameter);
}
bool ICommand.CanExecute(object parameter)
{
return CanExecute(parameter);
}
public event EventHandler CanExecuteChanged
{
add { CommandManager.RequerySuggested += value; }
remove { CommandManager.RequerySuggested -= value; }
}
void ICommand.Execute(object parameter)
{
Execute(parameter);
}
#endregion
}
Now “ViewModel”
public class ViewModel
{
#region property
public Dictionary<string, Model_Sport> Sports { get; set; }
public DelegateCommand SportsResponseCommand { get; set; }
#endregion
public ViewModel()
{
Sports = new Dictionary<string, Model_Sport>();
SportsResponseCommand = new DelegateCommand(p => execute_SportsResponseCommand(p));
buildSports();
}
private void buildSports()
{
Model_Sport football = new Model_Sport("Football", SportsResponseCommand);
Model_Sport golf = new Model_Sport("Golf", SportsResponseCommand);
Model_Sport hockey = new Model_Sport("Hockey", SportsResponseCommand);
football.IsChecked = true; // just for test
Sports.Add(football.Name, football);
Sports.Add(golf.Name, golf);
Sports.Add(hockey.Name, hockey);
}
private void execute_SportsResponseCommand(object p)
{
// TODO :what ever you want
MessageBox.Show(p.ToString());
}
}
Now View
Remember to set datacontext for your Window
public MainWindow()
{
InitializeComponent();
this.DataContext = new ViewModel();
}
Then in XAML
<StackPanel HorizontalAlignment="Left" VerticalAlignment="Top" >
<CheckBox DataContext="{Binding Path=Sports[Football]}"
IsChecked="{Binding IsChecked, Mode=TwoWay}"
Command="{Binding Path=SportsResponseCommand}"
CommandParameter="Football"
Content="Football"
Margin="5" />
<CheckBox DataContext="{Binding Path=Sports[Hockey]}"
IsChecked="{Binding IsChecked, Mode=TwoWay}"
Command="{Binding Path=SportsResponseCommand}"
CommandParameter="Hockey"
Content="Hockey"
Margin="5" />
<CheckBox DataContext="{Binding Path=Sports[Golf]}" IsChecked="{Binding IsChecked, Mode=TwoWay}"
Command="{Binding Path=SportsResponseCommand}"
CommandParameter="Golf"
Content="Golf"
Margin="5" />
</StackPanel>

If you just want a property in your ViewModel to get updated when the IsChecked changes, replace the Binding for IsChecked to a boolean property in your ViewModel that raises NotifyPropertyChanged on its "set".
Now if you want to perform an action everytime IsChecked changes for one of the 3 CheckBoxes:
First of all, replace your CommandParameter with "{Binding RelativeSource={RelativeSource Mode=Self}}"
In your ViewModel (that should implement INotifyPropertyChanged), create an ICommand (SportsResponseCommand) that takes a CheckBox in parameter.
In the command's method, check for the Content of your CheckBox, and for the "IsChecked" property then do your stuff with them.
If you have further questions let me know.

You can assign a view model by using this
//for the view
partial class MainView:Window
{
InitializeComponent();
this.DataContext=new MainViewModel();
}
//ViewModel Code
public class MainViewModel: INotifyPropertyChanged
{
//INotifyPropertyChanged implementation
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
if (this.PropertyChanged != null)
this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
//bindable property
private bool _football;
public bool Football
{
get { return _football; }
set
{
if (value != _football)
{
_football = value;
this.OnPropertyChanged("Football");
}
}
}
//... and the same for Golf and Hockey
}`
and then you can implement Binding in XAML as
<CheckBox IsChecked="{Binding Football, Mode=TwoWay}"
Command="{Binding Path=SportsResponseCommand}"
CommandParameter="Football"
Content="Football"
Margin="5" />
<CheckBox IsChecked="{Binding Golf, Mode=TwoWay}"
Command="{Binding Path=SportsResponseCommand}"
CommandParameter="Football"
Content="Football"
Margin="5" />