src/Tizen.NUI/src/internal/WeakEventHandler.cs

   1 using System;
   2 using System.Reflection;
   3
   4 namespace Tizen.NUI
   5 {
   6     internal sealed class WeakEventHandler<TEventArgs> where TEventArgs : EventArgs
   7     {
   8         private readonly WeakReference _targetReference;
   9         private readonly MethodInfo _method;
  10
  11         public WeakEventHandler(EventHandler<TEventArgs> callback)
  12         {
  13             _method = callback.GetMethodInfo();
  14             _targetReference = new WeakReference(callback.Target, true);
  15         }
  16
  17         public void Handler(object sender, TEventArgs e)
  18         {
  19             var target = _targetReference.Target;
  20             if (target != null)
  21             {
  22                 var callback = (Action<object, TEventArgs>)_method.CreateDelegate(typeof(Action<object, TEventArgs>), target);
  23                 if (callback != null)
  24                 {
  25                     callback(sender, e);
  26                 }
  27             }
  28         }
  29 }
  30
  31 }
  32