In order the application to respond to user input WPF offers 2 concepts . Lot of people get confused with events and commands.  When do you use what?

When to choose which?

Handling input in WPF  is done by

1. Event Handling 

2. Command Handling

Events

• Events represent low level interactions.
• Events are faster than commands. To learn more about types of events and how WPF events are handled Please go through the previous post

Commands

• Commands respond to actions. Commands represents high level input interactions like print, copy, paste, Which commands are associated to which action.
• Commands can be called from Menu item, Toolbar button, Keyboard, etc. Commands are more standard way to integrate Events.

Advantages of Commands

• Commands do not link to the caller, so commands are is not dependent  .
• A command can tell us if an action is possible or not. This can be done by  implementing the CanExecute method. A button can attach CanExecuteChanged event and will be disabled if CanExecute returns false. The same button can be enabled if CanExecute returns true. So Commands provide support for enabling/disabling all related UI controls based on this status of command.

Its best practice to use commands over events at real project, especially if you  use MVVM design pattern.

In the next post we will examine how to implement and handle commands in WPF