How to create event receivers using Visual Studio 2010 in SharePoint 2010?

Before this you can check What is event receiver in SharePoint 2010 ? 
We can create event receivers using Visual Studio 2010 in our SharePoint 2010 site. You can follow the below steps for the same.

Step-1:

Open Visual Studio 2010 -> File -> New Project -> Select SharePoint 2010 under Visual C# section. Then choose Event Receiver project template from the list of templates. Give a name for the project and click ok as shown in the figure below.

Step-2:

Then choose deploy as farm solution and give the URL for debugging in the drop down as shown below then

click on Next.

Step-3:

This step is very much important. Here first choose what type of receiver you want. Here I have added List Item Events.

Then select the event source and Here I have choose custom list.

Then choose what the events and I have selected Item Added and Item Updated Event. After selection the window should be look like the below figure.

Step-4

Now you can write code for the events that you have selected in Step-3. Here I have only add a sample code for a ItemAdding event as below. This will cancel the operation with error message if the particular list title is not “Test”.

Here is the code below:

public override void ItemAdding(SPItemEventProperties properties)

       {

           //base.ItemAdding(properties);

           if (properties.ListTitle != "Test")

           {

               properties.Status = SPEventReceiverStatus.CancelWithError;

               properties.ErrorMessage = "You can only add to the Test List !!!";

               properties.Cancel = true;

           }

       }
you can also check how to attach event receiver to SharePoint list.