Connected Web Part Series - Part 1

Problem: There is a lot of information relating to web parts however this series is aimed at connected web parts in SharePoint 2010.  This 1st post deals with creating a custom connection between 2 visual web parts (a provider & a consumer).

Overview:  Create a Interface to enable communication between the provider and the consumer web part.  Create Visual User controls to connect to each other. 
Tip: Web Parts are easier to connect than Visual Web Parts, so only use Visual web parts if there is a heavy visual requirement.

Steps:
Create a new Web Part (it will be the provider web part)

 Create an Interface (contract between the provider and consumer web parts)

 Implement the Interface in the Provider web part

Create the Consumer web part as shown below

Deploy the solution and activate the feature that contains the 2 web parts

In a browser add the 2 web parts to a page (Provider & Consumer) 

 Connect the 2 web parts as shown below