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DependencyProperty for collection of buttons

I want to give the user the opportunity to set a collection of buttons in my CustomControl.
I tried to solve this with ItemsControl like this:
<ItemsControl ItemsSource="{Binding RelativeSource={RelativeSource AncestorType={x:Type cc:MyCustomControl}}, Path=Buttons}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Button Command="{Binding Command}">
<Image Source="{Binding MyImageSource}"/>
</Button>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
Buttons DependencyProperty:
public static readonly DependencyProperty ButtonsProperty = DependencyProperty.Register(
"Buttons", typeof(IList), typeof(TileGrid), new PropertyMetadata(default(IList)));
public IList Buttons
{
get { return (IList) GetValue(ButtonsProperty); }
set { SetValue(ButtonsProperty, value); }
}
MyButton class:
public class MyButton: Button
{
public ImageSource MyImageSource { get; set; }
}
And how I want to see it in CustomControl implementation:
<cc:MyCustomControl>
<cc:MyCustomControl.Buttons>
<cc:MyButton Command="{Binding SignDocumentsCommand}"
MyImageSource="pack://application:,,,/CommonResources;component/Images/Icons/pen.png"/>
<cc:MyButton Command="{Binding DeleteDocumentsCommand}"
MyImageSource="pack://application:,,,/CommonResources;component/Images/Icons/remove.png"/>
</cc:MyCustomControl.Buttons>
</cc:MyCustomControl>
But it's not working. In live visual tree i see only MyButtons inside ItemsControl. Is this a right approach? Or i need to solve it another way?

The type that you are using for the Button items in the ItemsControl should not be derived from Button. You may use something simple like shown below. It is also not necessary to declare the Buttons property as dependency property. A simple ObservableCollection is sufficient.
public class MyButtonItem : DependencyObject
{
public static DependencyProperty CommandProperty = DependencyProperty.Register(
nameof(Command), typeof(ICommand), typeof(MyButtonItem));
public static DependencyProperty ImageSourceProperty = DependencyProperty.Register(
nameof(ImageSource), typeof(ImageSource), typeof(MyButtonItem));
public ICommand Command
{
get { return (ICommand)GetValue(CommandProperty); }
set { SetValue(CommandProperty, value); }
}
public ImageSource ImageSource
{
get { return (ImageSource)GetValue(ImageSourceProperty); }
set { SetValue(ImageSourceProperty, value); }
}
}
public partial class MyCustomControl : UserControl
{
public MyCustomControl()
{
InitializeComponent();
}
public ObservableCollection<MyButtonItem> Buttons { get; }
= new ObservableCollection<MyButtonItem>();
}
The controls XAML would just be what you already have:
<ItemsControl ItemsSource="{Binding Buttons,
RelativeSource={RelativeSource AncestorType=UserControl}}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Button Command="{Binding Command}">
<Image Source="{Binding ImageSource}"/>
</Button>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
You would then add MyButtonItem objects to the Buttons collection:
<cc:MyCustomControl>
<cc:MyCustomControl.Buttons>
<cc:MyButtonItem
Command="{Binding SignDocumentsCommand}"
ImageSource="/CommonResources;component/Images/Icons/pen.png"/>
<cc:MyButtonItem
Command="{Binding DeleteDocumentsCommand}"
ImageSource="/CommonResources;component/Images/Icons/remove.png"/>
</cc:MyCustomControl.Buttons>
</cc:MyCustomControl>

How to set DataBinding for UserControl with ViewModel

I have a usercontrol with couple of controls inside. So I decide to use ViewModel to do managing for all those bindable value. But I find my binding is always null. So how to setup binding for ViewModel in usercontrol
MainWindows.xaml
<Window x:Class="Test.MainWindow"
Title="MainWindow" Height="450" Width="800">
<StackPanel>
<cus:Wizard WizardModel="{Binding MyModel}"/>
</StackPanel>
</Window>
MainWindows.xaml.cs
public partial class MainWindow : Window
{
private ViewModel vm = new ViewModel();
public MainWindow()
{
InitializeComponent();
DataContext = vm;
}
}
ViewModel.cs(MainWindow viewmodel)
public class ViewModel : INotifyPropertyChanged
{
private Model _MyModel;
public Model MyModel
{
get
{
return _MyModel;
}
set
{
_MyModel = value;
NotifyPropertyChanged("MyModel");
}
}
}
Wizard.xaml(my UserControl)
<UserControl mc:Ignorable="d"
d:DesignHeight="450" d:DesignWidth="800">
<Grid>
<TextBox Grid.Row="0" Grid.Column="1" Text="{Binding Something}" />
</Grid>
</UserControl>
Wizard.xaml.cs
public partial class Wizard : UserControl
{
private readonly object modelLock = new object();
private Model CurrentModel = new Model();
public Wizard()
{
InitializeComponent();
DataContext = CurrentModel;
}
public Model WizardModel
{
get { return (Model)this.GetValue(WizardModelProperty); }
set { this.SetValue(WizardModelProperty, value); }
}
public static readonly DependencyProperty WizardModelProperty = DependencyProperty.Register("WizardModel", typeof(Model), typeof(Wizard), new PropertyMetadata(null, new PropertyChangedCallback(ModelChanged)));
private static void ModelChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
((Wizard)d).OnModelChanged();
}
private void OnModelChanged()
{
lock (this.modelLock)
{
if(CurrentModel != null)
{
CurrentModel = null;
}
if (WizardModel != null)
{
CurrentModel = WizardModel;
}
}
}
}
The WizardModel in UserControl is always null. So how to setup this ViewModel in UserControl

A UserControl that is supposed to operate on a particular view model class - or more precisely on a class with a particular set of public properties - may directly bind to the view model properties in its XAML.
Given a view model like
public class Model
{
public string Something { get; set; }
}
you may write a UserControl with nothing more than this XAML
<UserControl ...>
...
<TextBox Text="{Binding Something}" />
...
</UserControl>
and this code behind
public partial class Wizard : UserControl
{
public Wizard()
{
InitializeComponent();
}
}
If you now set its DataContext to an instance of Model (or any other class with a Something property), it will just work:
<local:Wizard DataContext="{Binding MyModel}"/>
Since the value of the DataContext property is inherited from parent to child elements, this will also work:
<StackPanel DataContext="{Binding MyModel}">
<local:Wizard/>
</StackPanel>
However, the UserControl still dependends on the existence of a Something property in its DataContext. In order to get rid of this dependence, your control may expose a dependency property
public static readonly DependencyProperty MyTextProperty =
DependencyProperty.Register(nameof(MyText), typeof(string), typeof(Wizard));
public string MyText
{
get { return (string)GetValue(MyTextProperty); }
set { SetValue(MyTextProperty, value); }
}
and bind the element in its XAML to its own property
<UserControl ...>
...
<TextBox Text="{Binding MyText,
RelativeSource={RelativeSource AncestorType=UserControl}}"/>
...
</UserControl>
Now you would bind the control's property instead of setting its DataContext:
<local:Wizard MyText="{Binding MyModel.Something, Mode=TwoWay}"/>

Binding Command to ViewModel inside UserControl

I want to bind a UserControl to a ViewModel to use Commands/Events.
My application consists of a MainWindow with a ContentControl inside, which is used to display a UserControls (the actual content) for navigation purposes.
MainWindow.xaml
<Window>
<Window.Resources>
<DataTemplate DataType="">
<View: />
</DataTemplate>
</Window.Resources>
<Menu>
<MenuItem Header="Connection" Command="..." />
</Menu>
<Grid>
<ContentControl Content="{Binding SelectedViewModel}" />
</Grid>
</Window>
MainViewModel.cs
class MainViewModel : ViewModelBase {
public ICommand MenuCommand;
private object _SelectedViewModel;
public object SelectedViewModel
{
get { return _SelectedViewModel; }
set
{
_SelectedViewModel = value;
RaisePropertyChanged("SelectedViewModel");
}
}
public MainViewModel()
{
ICommand = new RelayCommand(MenuClick);
}
private void MenuClick(object obj)
{
SelectedViewModel = new ConnectionViewModel();
}
}
This is how the navigation of my app works. The only problem I'm having is that I can't seem
to use Commands (Button for example) in the UserControl itself.
ConnectionView.xaml
<UserControl>
<Grid>
<Button Command="{Binding ButtonCommand}" Content="Button" />
</Grid>
</UserControl>
ConnectionViewModel.cs
class ConnectionViewModel : ViewModelBase {
public ICommand ButtonCommand;
public ConnectionViewModel()
{
ButtonCommand = new RelayCommand(ButtonClick);
}
private void ButtonClick(object obj)
{
MessageBox.Show("Clicked");
}
}
I can fill ListViews in the UserControl View but I can't get the Button Command working. What exactly is the problem, where did I go wrong?

ButtonCommand must be a property for you to be able to bind to it:
public ICommand ButtonCommand { get; private set; }
You have defined it as a field:
public ICommand ButtonCommand;

Dependecy property ICommand doesn't work in nested control

I have a UserControl with DependecyProperty:
public static readonly DependencyProperty OpenCommandProperty =
DependencyProperty.Register(
"OpenCommand",
typeof(ICommand),
typeof(BaseRouteFlatView),
new UIPropertyMetadata(null));
public ICommand OpenCommand
{
get { return (ICommand)GetValue(OpenCommandProperty); }
set { SetValue(OpenCommandProperty, value); }
}
In Xaml:
<UserControl x:Name="myUserControl">
<StackPanel>
<Button x:Name="first" Command="{Binding OpenCommand, ElementName=myUserControl}"/> <!--Command works-->
<controls:DropDownButtonControl>
<controls:DropDownButtonControl.DropDownContent>
<Button x:Name="second" Command="{Binding OpenCommand, ElementName=myUserControl}"/> <!--Command doesn't work-->
</controls:DropDownButtonControl.DropDownContent>
</controls:DropDownButtonControl>
</StackPanel>
</abstractions:UserControlBase>
What source I have to specify for working command in second button?

Try the following:
public UserControl()
{
InitializeComponent();
NameScope.SetNameScope(second, NameScope.GetNameScope(this));
}

How to excecute a command declared in child viewmodel in an MVVM app?

I've got a MainWindowVM and multiple child viewmodels inheriting from it.
MainWindowVM inherits from ViewModelBase which implements INotifyPropertychanged.
Each view has DataContext set to CurrentViewModel defined in MainWindowVM and every button
has got a binding to a command.
If I put the commands (and other command-handling code in the constructor) in the MainWindowVM,
button clicks in every view works as expected. I set MainControlVM as CurrentViewModel in the constructor of MainWindowVM.
Except for MainControlVM and MainWindowVM, setting commands in any other VM means they wont execute.
However, I want to have commands only in the VMs they are used.
I found many tutorials on MVVM with only one or two viewmodels so this situation isnt an issue for them.
Edit including code:
This is the relevant code:
Part of one of the child views in XAML with a binding:
<Grid DataContext="{Binding CurrentViewModel}" Margin="0,0,-186,0">
<Button Content="Add" HorizontalAlignment="Left" Margin="25,249,0,0" VerticalAlignment="Top" Width="62" Height="32"
Command="{Binding AddCategoryVMCommand}" />
MainWindowVM class contains:
public ICommand AddCategoryVMCommand { get; private set; }
and, in the constructor:
AddCategoryVMCommand = new RelayCommand(() => ExecuteAddCategoryVMCommand());
and:
protected void ExecuteAddCategoryVMCommand()
{
CurrentViewModel = new AddCategoryVM();
}
....and the same kind of code for each command. Aso, CurrentViewModel is set in the MainWindowVM class. This is the property that the MainWindow view uses to determine which view to display along with a datatemplate:
public ViewModelBase CurrentViewModel
{
get { return _currentViewModel; }
set
{
if (_currentViewModel == value)
return;
_currentViewModel = value;
this.RaiseNotifyPropertyChanged("CurrentViewModel");
}
}
How can I make commands execute when declared in child viewmodel?

There are a lot of comments going on, all out of sync and they appear to convolute the issue so I thought I would try to solve your problem with a basic example. The example deals solely with the command binding issue you appear to have.
I have created 3 ViewModel's, MyViewModel1 and MyViewModel2 are derived of MyViewModel. There is a command defined in the base ViewModel which is used to load the CurrentViewModel. The other 2 ViewModels contain their own commands.
public class MyViewModel : INotifyPropertyChanged
{
private MyViewModel currentViewModel;
public RelayCommand<object> MyCommand { get; set; }
public MyViewModel()
{
MyCommand = new RelayCommand<object>(MyCommandExecute);
}
public MyViewModel CurrentViewModel
{
get { return currentViewModel; }
set
{
if (value != currentViewModel)
{
currentViewModel = value;
OnPropertyChanged();
}
}
}
protected virtual void MyCommandExecute(object obj)
{
switch (int.Parse(obj.ToString()))
{
case 1:
CurrentViewModel = new MyViewModel1();
break;
case 2:
CurrentViewModel = new MyViewModel2();
break;
}
}
protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
var handler = this.PropertyChanged;
if (handler != null)
{
handler.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
public event PropertyChangedEventHandler PropertyChanged;
}
public class MyViewModel1 : MyViewModel
{
public RelayCommand<object> MyCommand1 { get; set; }
public MyViewModel1()
{
MyCommand1 = new RelayCommand<object>(MyCommand1Execute);
}
private void MyCommand1Execute(object obj)
{
Debug.WriteLine("MyCommand1");
}
}
public class MyViewModel2 : MyViewModel
{
public RelayCommand<object> MyCommand2 { get; set; }
public MyViewModel2()
{
MyCommand2 = new RelayCommand<object>(MyCommand2Execute);
}
private void MyCommand2Execute(object obj)
{
Debug.WriteLine("MyCommand2");
}
}
The code behind the UserControl1 is
public partial class UserControl1 : UserControl
{
public static readonly DependencyProperty ViewModelProperty = DependencyProperty.Register("ViewModel", typeof(MyViewModel1), typeof(UserControl1));
public UserControl1()
{
InitializeComponent();
}
public MyViewModel1 ViewModel
{
get { return GetValue(ViewModelProperty) as MyViewModel1; }
set { SetValue(ViewModelProperty, value); }
}
}
I have created the ViewModel Property as a DependencyProperty so I can bind to it from the MainWindow.
The Xaml of the user control is
<UserControl x:Class="StackOverflow._20937791.UserControl1" 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:this="clr-namespace:StackOverflow._20937791"
mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="300">
<StackPanel DataContext="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type this:UserControl1}}, Path=ViewModel}">
<Button Content="View 1 Command" Command="{Binding Path=MyCommand1}" />
</StackPanel>
</UserControl>
Note I have set up the DataContext on the first content element of the control. The bindings on all child elements are against the ViewModel of the UserControl while any incoming bindings (from the parent control) will be evaluated from the DataContext of that parent control.
Another point to note is that by defining the DataContext in the Xaml, you will get autocomplete in the Binding expressions which will cut down on bad expression errors.
The second UserControl is the same but the ViewModel is of type MyViewModel2.
Finally, the code for the MainWindow is
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
public MyViewModel ViewModel { get; set; }
}
The Xaml is
<Window x:Class="StackOverflow._20937791.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:this="clr-namespace:StackOverflow._20937791"
DataContext="{Binding RelativeSource={RelativeSource Self}, Path=ViewModel}"
Title="MainWindow" Height="200" Width="300">
<Window.Resources>
<DataTemplate DataType="{x:Type this:MyViewModel1}">
<this:UserControl1 ViewModel="{Binding}" />
</DataTemplate>
<DataTemplate DataType="{x:Type this:MyViewModel2}">
<this:UserControl2 ViewModel="{Binding}" />
</DataTemplate>
</Window.Resources>
<StackPanel>
<StackPanel Orientation="Horizontal">
<Button Content="Show View 1" Command="{Binding Path=MyCommand}" CommandParameter="1" Width="100" Margin="4" />
<Button Content="Show View 2" Command="{Binding Path=MyCommand}" CommandParameter="2" Width="100" Margin="0 4" />
</StackPanel>
<ContentControl Content="{Binding Path=CurrentViewModel}" Margin="20" />
</StackPanel>
</Window>
The UserControl is referenced in the main window and it has its ViewModel passed in.
The application shows a window that looks like
I hope this helps.

Firt, FYI - your approach is called the strategy pattern.
Now what you are doing sounds right but it's hard withou seeing your xaml.
Maybe you need to raise a propertychanged event after setting your vm properties?

It would be helpful if you would post your code .But if I havent misunderstood your question then you can try this
<Button Command="{Binding MainControlVM.ClickCommand}"
Set the binding MainControlVM.ClickCommand .Here ClickCommand is the name of your Command.
Update
I think the issue is in Setting the CurrentViewModel. You are setting the CurrentViewModel in the Action Of Command. I think you want to set the CurrentViewModel on the basis of Command. I think this could be better by CommandParameter . Like Bind all Buttons to same Base ViewModel Command and from each Command pass the different CommandParameter and then on Command compare that CommandParameter and set CurrentViewModel accordingly.
ViewModelBase ,Child1ViewModel ,Child2ViewModel
public class ViewModelBase:INotifyPropertyChanged
{
private ICommand _clickCommand;
public ICommand ClickCommand
{
get
{
return _clickCommand ?? (_clickCommand = new CommandHandler(MyAction,()=>true));
}
}
public void MyAction(object obj)
{
if(obj == null )
return;
//if CommandParameter is Cild1VM
if (obj.ToString() == "Child1VM")
CurrentViewModel = new Child1ViewModel();
//if CommandParameter is Cild1VM
else if (obj.ToString() == "Child2VM")
CurrentViewModel = new Child2ViewModel();
}
ViewModelBase _currentViewModel;
public ViewModelBase CurrentViewModel
{
get { return _currentViewModel; }
set
{
if (_currentViewModel == value)
return;
_currentViewModel = value;
this.RaiseNotifyPropertyChanged("CurrentViewModel");
}
}
public event PropertyChangedEventHandler PropertyChanged;
void RaiseNotifyPropertyChanged(string propName)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propName));
}
}
public class Child1ViewModel : ViewModelBase
{ }
public class Child2ViewModel : ViewModelBase
{ }
xaml
<StackPanel>
<Button Content="Foo" Command="{Binding ClickCommand}" CommandParameter="Child1VM"/>
<Button Content="Bar" Command="{Binding ClickCommand}" CommandParameter="Child2VM"/>
</StackPanel>
xaml.cs
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
DataContext = new ViewModelBase();
}
}
I hope this will give you an idea.