Managed C++/CLI

<br />
	__delegate void CallBackNewFile(String* fname,int size);<br />
	__delegate void CallBackBytes(int size);<br />
<br />
	__gc class ExtractInfo<br />
	{<br />
	public:<br />
		CallBackNewFile* newfile;<br />
		CallBackBytes* bytes;<br />
	};<br />

<br />
		static bool Extract(String* cabfile,String* DestDir,bool DontMakeFolders,<br />
			CallBackNewFile* newfile,CallBackBytes* bytes)<br />
		{<br />
			CCabExtractor cab;<br />
			if (!cab.Create())<br />
				return false;<br />
			ExtractInfo __pin * inf=new ExtractInfo();<br />
			inf->newfile=newfile;<br />
			inf->bytes=bytes;<br />
			cab.SetCallback(&mycallback,inf);<br />
<br />

<br />
  void SetCallback (CALLBACKFUNC pCallback, void * pv)<br />

<br />
static bool __stdcall mycallback (void * pv, const char * lpszPath,  DWORD cb)<br />
		{<br />
			ExtractInfo* i=(ExtractInfo*)(pv);<br />
			if (lpszPath==NULL)<br />
			{<br />
				if (i->bytes)<br />
					i->bytes(cb);<br />
			} else {<br />
				if (i->newfile)<br />
					i->newfile(lpszPath,cb);<br />
			}<br />
			return true;<br />
		}<br />

<br />
public __gc class Foo<br />
{<br />
public:<br />
   System::String * ToString();<br />
private:<br />
   static const System::String * ClassID = S"This is class Foo";<br />
};<br />
<br />
System::String * Foo::ToString()<br />
{<br />
    //This won't work because return value is non-const<br />
    //return Foo::ClassID;<br />
<br />
    //This won't work either, as callee might manipulate string<br />
    // return const_cast<System::String*>(Foo::ClassID);<br />
<br />
    // The only possibility?<br />
   return static_cast<System::String*>(const_cast<System::String*>(Foo::ClassID)->Clone());<br />
}<br />

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      // Defines a key for storing the delegate for the Click event
      // in the Events list.
      private static readonly object ClickEvent = new object();
      
      // Defines the Click event using the event property syntax.
      // The Events property stores all the event delegates of
      // a control as name/value pairs. 
      public event EventHandler Click 
      {
         // When a user attaches an event handler to the Click event 
         // ( Click += myHandler; ), the Add method 
         // adds the handler to the 
         // delegate for the Click event (keyed by ClickEvent 
         // in the Events list).
         add 
         {
            Events.AddHandler(ClickEvent, value);
         }
         // When a user removes an event handler from the Click event 
         // ( Click -= myHandler; ), the Remove method 
         // removes the handler from the 
         // delegate for the Click event (keyed by ClickEvent 
         // in the Events list).
         remove 
         {
            Events.RemoveHandler(ClickEvent, value);
         }
      }
      
      // Invokes delegates registered with the Click event.
      //
      protected virtual void OnClick(EventArgs e) 
      {
         // Retrieves the event delegate for the Click event
         // from the Events property (which stores
         // the control's event delegates). You must
         // cast the retrieved delegate to the type of your 
         // event delegate.
         EventHandler clickEventDelegate = (EventHandler)Events[ClickEvent];
         if (clickEventDelegate != null) {
            clickEventDelegate(this, e);
         }  
      }
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