using System; using System.Diagnostics; using System.Windows.Input; namespace Selen.Wpf.GenericAppTree { /// <summary> /// A command whose sole purpose is to /// relay its functionality to other /// objects by invoking delegates. The /// default return value for the CanExecute /// method is 'true'. /// </summary> internal class RelayCommand : ICommand { #region Fields readonly Action<object> _execute; readonly Predicate<object> _canExecute; #endregion // Fields #region Constructors /// <summary> /// Creates a new command that can always execute. /// </summary> /// <param name="execute">The execution logic.</param> public RelayCommand(Action<object> execute) : this(execute, null) { } /// <summary> /// Creates a new command. /// </summary> /// <param name="execute">The execution logic.</param> /// <param name="canExecute">The execution status logic.</param> public RelayCommand(Action<object> execute, Predicate<object> canExecute) { if (execute == null) throw new ArgumentNullException("execute"); _execute = execute; _canExecute = canExecute; } #endregion // Constructors #region ICommand Members [DebuggerStepThrough] public bool CanExecute(object parameter) { return _canExecute == null ? true : _canExecute(parameter); } public event EventHandler CanExecuteChanged { add { CommandManager.RequerySuggested += value; } remove { CommandManager.RequerySuggested -= value; } } public void Execute(object parameter) { _execute(parameter); } #endregion // ICommand Members } }
By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.
If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.
This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)