EventHandler without event keyword in C#

What is the differences between these?

1. public event EventHandler eEH;
2. public EventHandler EH;

They are very similar, but different:

• The first one is an event, the second one is a public field of delegate type.
• No one can assign a delegate to your event, they only can add (+=) or remove delegates (-=), but in addition to add (+=), and remove (-=), they can assign (=) delegate to the public field.
• No one can raise event like a delegate outside of your class, but they can invoke your public delegate field.
• Like properties and methods, you can define events in interfaces but you cannot do the same for fields.

Example - Difference between an event and a delegate field

Here are a few examples to demonstrate the differences which I mentioned above:

• class1.MyEvent = Something; doesn't work.
• class1.MyDelegateField = Something works and will assign a new multicast delegate to the field.
• class1.MyEvent(); doesn't work outside of your class.
• class1.MyDelegateField(); works and will run all the delegates which has been assigned to the field.
• interface ISomething { event EventHandler MyEvent;} is a valid declaration.
• interface ISomething { EventHandler MyDelegateField} is invalid.

More information

You can learn more about the events:

• Events (C# Programming Guide)
• Handle and raise events
• event (C# reference)