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WPF: A Most Useful Threading Component

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30 Dec 2009CPOL19 min read 121.2K   1.2K   147  
A threading component that shows failures/busy status and data.
using System;
using System.Windows.Input;

/// <summary>
/// This class provides a simple
/// delegate command that implements the ICommand
/// interface
/// </summary>
namespace ThreadingComponent
{
    /// <summary>
    /// Implements the ICommand and wraps up all the verbose stuff so that you 
    /// can just pass 2 delegates 1 for the CanExecute and one for the Execute
    /// </summary>
    public class SimpleCommand : ICommand
    {
        #region Public Properties
        public Boolean CommandSucceeded { get; set; }

        /// <summary>
        /// Gets or sets the Predicate to execute when the 
        /// CanExecute of the command gets called
        /// </summary>
        public Predicate<object> CanExecuteDelegate { get; set; }

        /// <summary>
        /// Gets or sets the action to be called when the 
        /// Execute method of the command gets called
        /// </summary>
        public Action<object> ExecuteDelegate { get; set; }
        #endregion

        #region ICommand Members

        /// <summary>
        /// Checks if the command Execute method can run
        /// </summary>
        /// <param name="parameter">THe command parameter to be passed</param>
        /// <returns>Returns true if the command can execute. 
        /// By default true is returned so that if the user of SimpleCommand 
        /// does not specify a CanExecuteCommand delegate the command 
        /// still executes.</returns>
        public bool CanExecute(object parameter)
        {
            if (CanExecuteDelegate != null)
                return CanExecuteDelegate(parameter);
            return true;// if there is no can execute default to true
        }

        public event EventHandler CanExecuteChanged
        {
            add { CommandManager.RequerySuggested += value; }
            remove { CommandManager.RequerySuggested -= value; }
        }

        /// <summary>
        /// Executes the actual command
        /// </summary>
        /// <param name="parameter">THe command parameter to be passed</param>
        public void Execute(object parameter)
        {
            if (ExecuteDelegate != null)
            {
                ExecuteDelegate(parameter);
                CommandSucceeded = true;
            }
        }

        #endregion
    }
}

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License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Software Developer (Senior)
United Kingdom United Kingdom
I currently hold the following qualifications (amongst others, I also studied Music Technology and Electronics, for my sins)

- MSc (Passed with distinctions), in Information Technology for E-Commerce
- BSc Hons (1st class) in Computer Science & Artificial Intelligence

Both of these at Sussex University UK.

Award(s)

I am lucky enough to have won a few awards for Zany Crazy code articles over the years

  • Microsoft C# MVP 2016
  • Codeproject MVP 2016
  • Microsoft C# MVP 2015
  • Codeproject MVP 2015
  • Microsoft C# MVP 2014
  • Codeproject MVP 2014
  • Microsoft C# MVP 2013
  • Codeproject MVP 2013
  • Microsoft C# MVP 2012
  • Codeproject MVP 2012
  • Microsoft C# MVP 2011
  • Codeproject MVP 2011
  • Microsoft C# MVP 2010
  • Codeproject MVP 2010
  • Microsoft C# MVP 2009
  • Codeproject MVP 2009
  • Microsoft C# MVP 2008
  • Codeproject MVP 2008
  • And numerous codeproject awards which you can see over at my blog

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