There is no difference. In your first example, the compiler will automatically infer the delegate you would like to instantiate. In the second example, you explicitly define the delegate. 

Delegate inference was added in C# 2.0. So for C# 1.0 projects, second example was your only option. For 2.0 projects, the first example using inference is what I would prefer to use and see in the codebase - since it is  more concise.

    [object].[event] += anEvent;

is just syntactic sugar for -

    [object].[event] += new EventHandler(anEvent);

I don&#39;t think there is a difference. The compiler transforms the first into the second.

`RedirectToAction` is protected, and we can use it only inside actions. But if I want to redirect in a filter?

    public class IsGuestAttribute: ActionFilterAttribute
    {
        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            if (!Ctx.User.IsGuest) 
                filterContext.Result = (filterContext.Controller as Controller)
                    .RedirectToAction(&quot;Index&quot;, &quot;Home&quot;);
        }
    }


How to get filter to redirect to another action?

Here&#39;s the scenario...  

    if (entry.Properties[&quot;something&quot;].Value != null)
      attribs.something = entry.Properties[&quot;something&quot;].Value.ToString();

While effective and working correctly, this looks ugly to me.  If I don&#39;t check for a null before performing the ToString() then it throws an exception if the property was null.  Is there a better way to handle this scenario?

Much appreciated!

Checking for null before ToString()

Take the below code:

    private void anEvent(object sender, EventArgs e) {
        //some code
    }


----------


        
   What is the difference between the following ?

    [object].[event] += anEvent;
       
    //and
      
    [object].[event] += new EventHandler(anEvent);


**[UPDATE]**

Apparently, there is no difference between the two...the former is just syntactic sugar of the latter.

C#: Difference between &#39; += anEvent&#39; and &#39; += new EventHandler(anEvent)&#39;

Take the below code:
<pre><code class="hljs language-typescript">private void anEvent(object sender, EventArgs e) {
 //some code
}
</code></pre>
<hr>
What is the difference between the following ?
<pre><code class="hljs language-scss">[object].[event] += anEvent;
 
//and
 
[object].[event] += new EventHandler(anEvent);
</code></pre>
[UPDATE]
Apparently, there is no difference between the two...the former is just syntactic sugar of the latter.

I&#39;ve got the following (simplified):

    interface IFindFilesObserver
    {
        void OnFoundFile(FileInfo fileInfo);
        void OnFoundDirectory(DirectoryInfo directoryInfo);
    }

    class FindFiles
    {
        IFindFilesObserver _observer;

        // ...
    }

...and I&#39;m conflicted. This is basically what I would have written in C++, but C# has events. Should I change the code to use events, or should I leave it alone?

What are the advantages or disadvantages of events over a traditional observer interface?


C#: events or an observer interface? Pros/cons?

I am trying to implement GZip compression for my asp.net page (including my CSS and JS files). I tried the following code, but it only compresses my .aspx page (found it from [YSlow][1])

    HttpContext context = HttpContext.Current;
    context.Response.Filter = new GZipStream(context.Response.Filter, CompressionMode.Compress);
    HttpContext.Current.Response.AppendHeader(&quot;Content-encoding&quot;, &quot;gzip&quot;);
    HttpContext.Current.Response.Cache.VaryByHeaders[&quot;Accept-encoding&quot;] = true;

The above code is only compressing my .aspx page code (markup) not the CSS and JS files which is included as external files. 
Please tell me how can I implement GZip compression in ASP.NET using code (because I am on shared hosting server where I don&#39;t have access to IIS Server configurations). And also in the above code I am not getting the last two lines, why they are used and what&#39;s the purpose of these lines. Please explain!


  [1]: http://developer.yahoo.com/yslow/

How to implement GZip compression in ASP.NET?

How to hide TabPage from TabControl in WinForms 2.0?

How to hide TabPage from TabControl

In C# the Main class has string[] args parameter.

What is that for and where does it get used?


What is &quot;string[] args&quot; in Main class for?

How do you compile and execute a .cs file from a command-prompt window?

Compiling/Executing a C# Source File in Command Prompt

I don&#39;t see advantages of using events over delegates, other than being syntactical sugar. Perhaps I am misunderstanding, but it seems that event is just a placeholder for delegate.

Would you explain to me the differences and when to use which?  What are the advantages and disadvantages? Our code is heavily rooted with events, and I want to get to the bottom of it.

When would you use delegates over events and vice versa? Please state your real world experience with both, say in the production code.

  [1]: http://stackoverflow.com/questions/29155/what-is-the-difference-between-a-delegate-and-events/29170#29170

Difference between events and delegates and its respective applications

Can someone provide a good explanation (hopefully with examples) of these 3 most important delegates:

* Predicate
* Action
* Func

Delegates: Predicate vs. Action vs. Func

Being new to objective-c, cocoa, and iPhone dev in general, I have a strong desire to get the most out of the language and the frameworks.

  One of the resources I&#39;m using is Stanford&#39;s CS193P class notes that they have left on the web.  It includes lecture notes, assignments and sample code, and since the course was given by Apple dev&#39;s, I definitely consider it to be &quot;from the horse&#39;s mouth&quot;.

Class Website:  
&lt;http://www.stanford.edu/class/cs193p/cgi-bin/index.php&gt;

  Lecture 08 is related to an assignment to build a UINavigationController based app that has multiple UIViewControllers pushed onto the UINavigationController stack.  That&#39;s how the UINavigationController works.  That&#39;s logical.  However, there are some stern warnings in the slide about communicating between your UIViewControllers.

I&#39;m going to quote from this serious of slides:  
&lt;http://cs193p.stanford.edu/downloads/08-NavigationTabBarControllers.pdf&gt;

Page 16/51:
&gt; How Not To Share Data
&gt; =====================
&gt; - Global Variables or singletons
&gt;   - This includes your **application delegate**
&gt; - Direct dependencies make your code less reusable
&gt;   - And more difficult to debug &amp; test

  Ok.  I&#39;m down with that.  Don&#39;t blindly toss all your methods that will be used for communicating between the viewcontroller into your app delegate and reference the viewcontroller instances in the app delegate methods.  Fair &#39;nuff.

  A bit further on, we get this slide telling us what we *should* do.

Page 18/51:
&gt; Best Practices for Data Flow
&gt; ============================
&gt; - Figure out **exactly** what needs to be communicated
&gt; - **Define input parameters** for your view controller
&gt; - For communicating back up the hierarchy, **use loose coupling**
&gt;   - Define a generic interface for observers (like delegation)

  This slide is then followed by what appears to be a place holder slide where the lecturer then apparently demonstrates the best practices using an example with the UIImagePickerController.  I wish the videos were available! :(

  Ok, so... I&#39;m afraid my objc-fu is not so strong.  I&#39;m also a bit confused by the final line in the above quote.  I&#39;ve been doing my fair share of googling about this and I found what appears to be a decent article talking about the various methods of Observing/Notification techniques:  
&lt;http://cocoawithlove.com/2008/06/five-approaches-to-listening-observing.html&gt;

  Method #5 even indicates delegates as an method!  Except.... objects can only set one delegate at a time.  So when I have multiple viewcontroller communication, what am I to do?

  Ok, that&#39;s the set up gang.  I know I can easily do my communication methods in the app delegate by reference&#39;s the multiple viewcontroller instances in my appdelegate but I want to do this sort of thing the *right* way.

  Please help me &quot;do the right thing&quot; by answering the following questions:

1. When I am trying to push a new viewcontroller on the UINavigationController stack, **who** should be doing this push.  **Which** class/file in my code is the correct place?
2. When I want to affect some piece of data (value of an iVar) in one of my UIViewControllers when I am in a **different** UIViewController, what is the &quot;right&quot; way to do this?
3. Give that we can only have one delegate set at a time in an object, what would the implementation look like for when the lecturer says *&quot;Define a generic interface for observers (like delegation)&quot;*.  A pseudocode example would be awfully helpful here if possible.

What&#39;s the best way to communicate between view controllers?

I know how delegates work, and I know how I can use them.

But how do I create them?

How do I create delegates in Objective-C?

I need to know about the usage of delegate methods in Objective-C. Can anyone point me to the correct source?

How to use custom delegates in Objective-C

I need to debug a web application that uses jQuery to do some fairly complex and messy [DOM][1] manipulation. At one point, some of the events that were bound to particular elements, are not fired and simply stop working.

If I had a capability to edit the application source, I would drill down and add a bunch of [Firebug][2] `console.log()` statements and comment/uncomment pieces of code to try to pinpoint the problem. But let&#39;s assume I cannot edit the application code and need to work entirely in Firefox using Firebug or similar tools.

Firebug is very good at letting me navigate and manipulate the DOM. So far, though, I have not been able to figure out how to do event debugging with Firebug. Specifically, I just want to see a list of event handlers bound to a particular element at a given time (using Firebug JavaScript breakpoints to trace the changes). But either Firebug does not have the capability to see bound events, or I&#39;m too dumb to find it. :-)

Any recommendations or ideas? Ideally, I would just like to see and edit events bound to elements, similarly to how I can edit DOM today.

  [1]: http://en.wikipedia.org/wiki/Document_Object_Model
  [2]: http://en.wikipedia.org/wiki/Firebug_%28software%29


How to debug JavaScript / jQuery event bindings with Firebug or similar tools?

Which is more widely supported: `window.onload` or `document.onload`?

window.onload vs document.onload

I&#39;ll try to explain the problem with a simple code.

    var fireClick = function() { alert(&#39;Wuala!!!&#39;) };
    
    $(&#39;#clickme&#39;).click(fireclick);
    $(&#39;#clickme&#39;).click(fireclick);

So now it will obviously alert 2 times but i need it alert only once. Tried so many ways, but no result. 

Thanks.

How to overwrite jquery event handlers

I understand the purpose of events, especially within the context of creating user interfaces. I think this is the prototype for creating an event:

    public void EventName(object sender, EventArgs e);

What do event handlers do, why are they needed, and how do I to create one?


Understanding events and event handlers in C#

Duplicate of: [How to ensure an event is only subscribed to once][1]
and [Has an event handler already been added?][2]


I have a singleton that provides some service and my classes hook into some events on it, sometimes a class is hooking twice to the event and then gets called twice.
I&#39;m looking for a classical way to prevent this from happening. somehow I need to check if I&#39;ve already hooked to this event...


  [1]: https://stackoverflow.com/questions/367523/how-to-ensure-an-event-is-only-subscribed-to-once
  [2]: https://stackoverflow.com/questions/136975/has-an-event-handler-already-been-added

Content Type	Original Author	Original Content on Stackoverflow
Question	Andreas Grech	View Question on Stackoverflow
Solution 1 - C#	driis	View Answer on Stackoverflow
Solution 2 - C#	Martin Jonáš	View Answer on Stackoverflow
Solution 3 - C#	Megacan	View Answer on Stackoverflow

C#: Difference between ' += anEvent' and ' += new EventHandler(anEvent)'

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

Solution 3 - C#

Checking for null before ToString()

How to get filter to redirect to another action?

Attributions