#1,078 – Defining a Command Binding Using Lambda Expressions

Recall that commands in WPF are objects that you bind UI elements to and that are in turn bound to code for executing the command and for knowing whether a command can be executed.

Below is an example that sets up a command binding using lambda expressions.

    <Window.ContextMenu>
        <ContextMenu>
            <MenuItem Header="Open" Command="ApplicationCommands.Open"/>
        </ContextMenu>
    </Window.ContextMenu>

    <StackPanel>
        <Button Content="Open" Command="ApplicationCommands.Open"
                Margin="10" HorizontalAlignment="Center" />
        <CheckBox Content="Can Open" IsChecked="{Binding CanOpenIsChecked}"
                  Margin="10"/>
    </StackPanel>

We set up the command binding in the window’s constructor.

    public partial class MainWindow : Window, INotifyPropertyChanged
    {
        public MainWindow()
        {
            InitializeComponent();
            this.DataContext = this;

            CommandBindings.Add(new CommandBinding(ApplicationCommands.Open,
                (sender, e) => { MessageBox.Show("Executing the Open command"); },
                (sender, e) => { e.CanExecute = CanOpenIsChecked; }));
        }

        // INotifyPropertyChanged
        public event PropertyChangedEventHandler PropertyChanged = delegate { };

        private void RaisePropertyChanged(string propName)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propName));
        }

        public bool CanOpenIsChecked { get; set; }
    }

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About Sean
Software developer in the Twin Cities area, passionate about .NET technologies. Equally passionate about my own personal projects related to family history and preservation of family stories and photos.

3 Responses to #1,078 – Defining a Command Binding Using Lambda Expressions

  1. Pingback: Dew Drop – May 22, 2014 (#1782) | Morning Dew

  2. Tousif says:

    Can we implement INotifyPropertychange on auto property
    public bool CanOpenIsChecked { get; set; }

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