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C.B.R.

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22 Oct 2012GPL329 min read 123.3K   132  
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// ****************************************************************************
// <copyright file="WeakAction.cs" company="GalaSoft Laurent Bugnion">
// Copyright © GalaSoft Laurent Bugnion 2009-2011
// </copyright>
// ****************************************************************************
// <author>Laurent Bugnion</author>
// <email>laurent@galasoft.ch</email>
// <date>18.9.2009</date>
// <project>GalaSoft.MvvmLight</project>
// <web>http://www.galasoft.ch</web>
// <license>
// See license.txt in this solution or http://www.galasoft.ch/license_MIT.txt
// </license>
// ****************************************************************************

using System;

namespace CBR.Core.Helpers
{
    /// <summary>
    /// Stores an <see cref="Action" /> without causing a hard reference
    /// to be created to the Action's owner. The owner can be garbage collected at any time.
    /// </summary>
    ////[ClassInfo(typeof(Messenger))]
    public class WeakAction
    {
        private readonly Action _action;

        private WeakReference _reference;

        /// <summary>
        /// Initializes a new instance of the <see cref="WeakAction" /> class.
        /// </summary>
        /// <param name="target">The action's owner.</param>
        /// <param name="action">The action that will be associated to this instance.</param>
        public WeakAction(object target, Action action)
        {
            _reference = new WeakReference(target);
            _action = action;
        }

        /// <summary>
        /// Gets the Action associated to this instance.
        /// </summary>
        public Action Action
        {
            get
            {
                return _action;
            }
        }

        /// <summary>
        /// Gets a value indicating whether the Action's owner is still alive, or if it was collected
        /// by the Garbage Collector already.
        /// </summary>
        public bool IsAlive
        {
            get
            {
                if (_reference == null)
                {
                    return false;
                }

                return _reference.IsAlive;
            }
        }

        /// <summary>
        /// Gets the Action's owner. This object is stored as a <see cref="WeakReference" />.
        /// </summary>
        public object Target
        {
            get
            {
                if (_reference == null)
                {
                    return null;
                }

                return _reference.Target;
            }
        }

        /// <summary>
        /// Executes the action. This only happens if the action's owner
        /// is still alive.
        /// </summary>
        public void Execute()
        {
            if (_action != null
                && IsAlive)
            {
                _action();
            }
        }

        /// <summary>
        /// Sets the reference that this instance stores to null.
        /// </summary>
        public void MarkForDeletion()
        {
            _reference = null;
        }
    }
}

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This article, along with any associated source code and files, is licensed under The GNU General Public License (GPLv3)


Written By
Architect
France France
WPF and MVVM fan, I practice C # in all its forms from the beginning of the NET Framework without mentioning C ++ / MFC and other software packages such as databases, ASP, WCF, Web & Windows services, Application, and now Core and UWP.
In my wasted hours, I am guilty of having fathered C.B.R. and its cousins C.B.R. for WinRT and UWP on the Windows store.
But apart from that, I am a great handyman ... the house, a rocket stove to heat the jacuzzi and the last one: a wood oven for pizza, bread, and everything that goes inside

https://guillaumewaser.wordpress.com/
https://fouretcompagnie.wordpress.com/

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