Microsoft launched their Expression Studio 4 today (7 June 2010), as expected. It includes Sketch Flow, Expression Encoder, Expression Web and Expression Design. This release comes with the Upgrade version. If you already have the licensed copy of Expression Studio 3, it will auto update to Expression 4 and you need no new license.

You can download it from Microsoft Expression Studio site.

Please note that, if you are developing in Silverlight for Windows Phone 7 and want to use Expression Blend, don’t install this version of Expression Studio. Continue working with the Expression Blend 4 Beta and the Windows Phone 7 CTP Tools for developers. Once the Windows Phone SDK releases, there will be service pack for Expression Studio.

Sometimes we write the following code while working with EventHandler and that may create some problems. I will discuss this later on. Let us see the code:


                private void RaiseOperationComplete(EventArgs e)
                {
                    if(OperationComplete != null)
                    {
                        OperationComplete(this, e);
                    }
                }


In the above case, suppose two thread subscribed to the same OperationComplete handler and one unsubscribed the event. In such scenario the OperationComplete event will become null and for the next thread due to the event is null it will not execute. This happens mainly in multithreaded applications but you can't guarantee for single threaded application too.

So what to do? How can we make sure that our application will not come into such situation and work properly?