EventHandler<T> and EventHandler
<p>I want to ask the different between <code>EventHandler</code> and <code>EventHandler&lt;T&gt;</code>.</p>

<p>Previously I have implemented a <code>EventHandler</code>, with a custom EventArgs which can be passed to the parent page from the user control. </p>

<p>I thought I need to apply <code>EventHandler&lt; T &gt;</code>, however it can be implemented by using <code>EventHandler</code>. (in fact there is weird error when I trying to apply <code>EventHandler&lt;T&gt;</code>, the program is worked but error is shown in the IDE which  I couldn't solve [<a href="https://stackoverflow.com/questions/41235495/c-sharp-custom-eventhandler">C# Custom EventHandler</a> ])</p>

<p>Thus, I want to know in what situation I need to apply <code>EventHandler &lt; T &gt;</code> ?</p>

<pre><code>public event EventHandler AppendProcess;
public event EventHandler&lt;MyEventArg&gt; AppendProcess;
</code></pre>

<p>---Update---
this is how I invoke the event in the user control (as i said, i can pass object to parent page by doing this (although i don't know if it is correct to do so)</p>

<pre><code>if (AppendProcess == null) { }
else
    AppendProcess(this, new Common.WinLose_ProgressStage(Common.WinLose_SP_Parameter.upper, displayLevel + 1, 
                                                            (int)Common.WinLose_Level.lvChild4, thename, refundratio, 
                                                            selfproportion, -1, -1, loadlevel, isPlayer, betsource, gamecategory, false));
</code></pre>