.NET EventHandlers - Generic or no?

Question

Every time I start in deep in a C# project, I end up with lots of events that really just need to pass a single item. I stick with the EventHandler/Event

Answer 1

To make generic event declaration easier, I created a couple of code snippets for it. To use them:

• Copy the whole snippet.
• Paste it in a text file (e.g. in Notepad).
• Save the file with a .snippet extension.
• Put the .snippet file in your appropriate snippet directory, such as:

Visual Studio 2008\Code Snippets\Visual C#\My Code Snippets

Here's one that uses a custom EventArgs class with one property:

  
    

      
      ev1Generic
      Code snippet for event handler and On method
      Ryan Lundy
      
        Expansion
      
    
    
      
        
          type
          Type of the property in the EventArgs subclass.
          propertyType
        
        
          argName
          Name of the argument in the EventArgs subclass constructor.
          propertyName
        
        
          propertyName
          Name of the property in the EventArgs subclass.
          PropertyName
        
        
          eventName
          Name of the event
          NameOfEvent
        
      
       $eventName$;
            protected virtual void On$eventName$($eventName$EventArgs e)
            {
                var handler = $eventName$;
                if (handler != null)
                    handler(this, e);
            }]]>
      
      
        
          System
        
      
    
  

And here's one that has two properties:

  
    

      
      ev2Generic
      Code snippet for event handler and On method
      Ryan Lundy
      
        Expansion
      
    
    
      
        
          type1
          Type of the first property in the EventArgs subclass.
          propertyType1
        
        
          arg1Name
          Name of the first argument in the EventArgs subclass constructor.
          property1Name
        
        
          property1Name
          Name of the first property in the EventArgs subclass.
          Property1Name
        
        
          type2
          Type of the second property in the EventArgs subclass.
          propertyType1
        
        
          arg2Name
          Name of the second argument in the EventArgs subclass constructor.
          property1Name
        
        
          property2Name
          Name of the second property in the EventArgs subclass.
          Property2Name
        
        
          eventName
          Name of the event
          NameOfEvent
        
      
      
         $eventName$;
            protected virtual void On$eventName$($eventName$EventArgs e)
            {
                var handler = $eventName$;
                if (handler != null)
                    handler(this, e);
            }]]>
      
      
        
          System
        
      
    
  

You can follow the pattern to create them with as many properties as you like.