Encapsulates a method that takes a single parameter and does not return a value.
public delegate void Action<T>(
T obj
)
You can use this delegate to pass a method as a parameter without explicitly declaring a custom delegate. The method must correspond to the method signature that is defined by this delegate. This means that the encapsulated method must have one parameter that is passed to it by value, and must not return a value. (In C#, the method must return void. Typically, such a method is used to perform an operation.