Plug-in programming framework under C #: MEF and MAF

Both MEF and MAF are the plug-in programming frameworks under C #, and we can easily implement the plug-in programming concept by simply configuring the source code and designing an extensible program. This is a wonderful thing!

MEF (Managed extensibility Framework)

The way MEF works is probably this: first, define an interface to use this interface to constrain the responsibilities that the plug-in needs to have; then add the Reflection Flag "[Export ()]" to the program method that implements the interface to export the implemented content, and finally load the plug-in into the interface's calling program through the properties. Let's use code to describe it:

1. Define an interface:

/* 
     
    Author: ghostbear 
    Blog: http://blog.csdn.net/ghostbear   
    Introduction: This section is mainly to learn about the plug-in programming framework under. NET MEF (Managed Extensibility Framework) 
     
 *
      
/using System;  
      
Using System.Collections.Generic;  
      
Using System.Linq;  
      
Using System.Text;  

Using System.Windows;  
 
Namespace Chapter28_simplecontract  
      
{public  
      
    interface ICalculator  
      
    {  
      
        ilist<ioperation> GetOperations ();  
      
        Double Operate (IOperation operation, double[] operands);  
      

    Public interface ioperation  
      
    {  
      
        string Name {get;}  
      
        int numberoperands {get;}  
      
    }  

    Public interface icaculatorextension  
      
    {  
      
        string Title {get;}  
      
        String Description {get;}  
      
        FrameworkElement Getui ();  
      
    }  
      

2. Implementation-defined interface (PART I)

    [Export (typeof (ICalculator))] public class Caculator:icalculator {public ilist&  
      
                Lt;ioperation> getoperations () {return new list<ioperation> () { New operation{Name= "+", numberoperands=2}, New Operation{name= "-", numberoperands=2} , New Operation{name= "*", numberoperands=2}, New Operation{name= "/", Numbe  
      
        roperands=2}}; Public double Operate (ioperation operation, double[] operands) {DOUBL  
      
            e result=0; Switch (operation. Name {case "+": result = Operands[0] + Opera  
      
                    NDS[1];  
      
                Break  
      
          Case "-": result = Operands[0]-operands[1];          Break  
      
                    Case "*": result = operands[0] * Operands[1];  
      
                Break  
      
                    Case "/": result = Operands[0]/operands[1];  
      
                Break  
      
            Default:throw New Exception ("not provide this method");  
      
        return result;  
      
        } public class Operation:ioperation {public string Name  
      
            {get;  
      
        Internal set;  
      
            public int Numberoperands {get;  
      
        Internal set; }  
      
    }