WPF how to Programmically create RightMouseClickEvent in both Code Behind and following MVVM

Question

WPF C# how do you create a MouseRightButtonDown Event for a Rectangle in code behind as well as following MVVM principles.
Code behind I thought would be something like this

rect.MouseRightButtonDown += rectangle_MouseRightButtonDown;

And implemented as follow:

private void rectangle_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
{

}

but it’s not working. I'm sure i must be missing something very obvious but would appreciate any assistance.

Answer 1

Here is an example of using RightMouseClickEvent in MVVM. You could add system.windows.interactivity.dll to the project.
MainWindow.xaml:

<Window x:Class="RightMouseClickEventOfRectangleMVVM.MainWindow"  
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"  
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"  
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"  
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"  
        xmlns:local="clr-namespace:RightMouseClickEventOfRectangleMVVM"  
        mc:Ignorable="d"  
        xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"   
        Title="MainWindow" Height="450" Width="800">  
    <Window.DataContext>  
        <local:ViewModel/>  
    </Window.DataContext>  
    <StackPanel>  
        <Rectangle x:Name="rect" Fill="{Binding MyColor}" HorizontalAlignment="Left"   
                   Height="100" Margin="10,29,0,0" Stroke="Black" VerticalAlignment="Top"  
                   Width="100" MouseRightButtonDown="rect_MouseRightButtonDown">  
            <i:Interaction.Triggers>  
                <i:EventTrigger EventName="MouseRightButtonDown">  
                    <i:InvokeCommandAction Command="{Binding MyCommand}"/>  
                </i:EventTrigger>  
            </i:Interaction.Triggers>  
        </Rectangle>  
        <Button x:Name="btn" Command="{Binding Button1Command}" Content="GO"/>  
    </StackPanel>  
</Window>  

MainWindow.xaml.cs:

using System;  
using System.ComponentModel;  
using System.Windows;  
using System.Windows.Input;  
using System.Windows.Media;  

namespace RightMouseClickEventOfRectangleMVVM  
{  
  public partial class MainWindow : Window  
  {  
    public MainWindow()  
    {  
      InitializeComponent();  
    }  
    private void rect_MouseRightButtonDown(object sender, MouseButtonEventArgs e)  
    {  
      MessageBox.Show("clicked");  
    }  
  }  
  public class ViewModel : INotifyPropertyChanged  
  {  
    private Brush myColor = Brushes.Red;  
    public Brush MyColor  
    {  
      get  
      {  
        return myColor;  
      }  
      set  
      {  
        myColor = value;  
        NotifyPropertyChanged("MyColor");  
      }  
    }  
    public DelegateCommand MyCommand { get; set; }  
    public DelegateCommand Button1Command { get; set; }  
    public ViewModel()  
    {  
      Button1Command = new DelegateCommand(onButton1Command);  
      MyCommand = new DelegateCommand(OnRectangleClicked);  
    }  

    private void OnRectangleClicked(object obj)  
    {  
      MyColor = Brushes.Pink;  
    }  

    private void onButton1Command(object obj)  
    {  
      MessageBox.Show("hello");  
    }  
    public event PropertyChangedEventHandler PropertyChanged;  
    protected void NotifyPropertyChanged(string propertyName)  
    {  
      if (PropertyChanged != null)  
      {  
        PropertyChangedEventArgs args = new PropertyChangedEventArgs(propertyName);  
        this.PropertyChanged(this, args);  
      }  
    }  
  }  
  public class DelegateCommand : ICommand  
  {  
    private readonly Predicate<object> _canExecute;  
    private readonly Action<object> _execute;  

    public event EventHandler CanExecuteChanged;  

    public DelegateCommand(Action<object> execute)  
        : this(execute, null)  
    {  
    }  
    public DelegateCommand(Action<object> execute, Predicate<object> canExecute)  
    {  
      _execute = execute;  
      _canExecute = canExecute;  
    }  

    public bool CanExecute(object parameter)  
    {  
      if (_canExecute == null)  
      {  
        return true;  
      }  

      return _canExecute(parameter);  
    }  

    public void Execute(object parameter)  
    {  
      _execute(parameter);  
    }  

    public void RaiseCanExecuteChanged()  
    {  
      if (CanExecuteChanged != null)  
      {  
        CanExecuteChanged(this, EventArgs.Empty);  
      }  
    }  
  }  
}  

The result:

---

If the response is helpful, please click "Accept Answer" and upvote it.
 Note: Please follow the steps in our [documentation][5] to enable e-mail notifications if you want to receive the related email notification for this thread. 

[5]: https://learn.microsoft.com/en-us/answers/articles/67444/email-notifications.html