Usage of delegate

background

delegate It literally means to entrust , representative , The representative of the meeting , to grant authorization , School selection . Many client engineers should be familiar , Especially the processing interface UI when , stay UI Library source code is often encountered , You may jump out MVC Pattern , Or there is this usage in other design patterns . Using them correctly can easily make complex pages concise 、 distinct .

Commission Overview
Dynamically associate the method caller with the target method , A delegate is a class , So it is peer to class , You can use methods through delegation , Don't mistakenly think that delegation and method are at the same level , Methods are just members of classes . Delegates define the type of method （ Defining a delegate and its corresponding method must have the same number of parameters , And of the same type , The return value type is the same ）, Make it possible to pass a method as an argument to another method , This method is dynamically assigned to parameters , Avoid extensive use in programs If-Else(Switch) sentence , At the same time, the program has better scalability .

About MVC

I Believe C# developer ,Java developer ,Android developer ,IOS Developers will be exposed to MVC framework .MVC Among them M Express model business model ,V Is said view The user interface ,C Express controller controller . Use MVC The goal is to M and V Implementation code separation of , So that the same program can use different forms of expression . among View The definition of , It's the user interface .

In fact, it's just Subdivide the business logic and controller To draw