Click here to Skip to main content
Click here to Skip to main content
Go to top

Run-Time Code Generation II: Invoke Methods using System.Reflection

, 18 Jan 2006
Rate this:
Please Sign up or sign in to vote.
Invoke methods using System.Reflection

Introduction

.NET provides mechanisms to compile source code and to use the generated assemblies within an application. Using these features, you can make applications more adaptive and more flexible.

This article shows how to invoke methods from an assembly using System.Reflection.

Necessary Using Statements

Before you start, add the following using statements to your application to ease the use of the namespaces:

using System.Reflection;
using System.Security.Permissions; 

Getting Started

At the beginning, you have to know which method from which type and from which module you want to call. Inspecting an assembly can be done very easily with System.Reflection too. But now we assume having all the knowledge about it because we generated it ourselves like in Run-Time Code Generation Part I.

So we just set the module's name, the type's name and the method's name:

string ModuleName = "TestAssembly.dll";
string TypeName = "TestClass";
string MethodName = "TestMethod";

Open an Assembly

Then you can open the assembly and set some Binding Flags, which are necessary for the instantiation of the chosen type:

Assembly myAssembly = Assembly.LoadFrom(ModuleName);

BindingFlags flags = (BindingFlags.NonPublic | BindingFlags.Public | 
  BindingFlags.Static | BindingFlags.Instance | BindingFlags.DeclaredOnly);

Invoke a Method

After that, three loops are used to inspect the assembly and get the chosen module/type/method combination. Within the last loop, the type is instantiated and the method is called. The method can be called with parameters, but here we choose null for methods with no parameters. There can also be a response from the method, which we put into a general object.

Module [] myModules = myAssembly.GetModules();
foreach (Module Mo in myModules) 
    {
     if (Mo.Name == ModuleName) 
         {
         Type[] myTypes = Mo.GetTypes();
         foreach (Type Ty in myTypes)
             {
            if (Ty.Name == TypeName) 
                {
                MethodInfo[] myMethodInfo = Ty.GetMethods(flags);
                foreach(MethodInfo Mi in myMethodInfo)
                    {
                    if (Mi.Name == MethodName) 
                        {
                        Object obj = Activator.CreateInstance(Ty);
                        Object response = Mi.Invoke(obj, null);
                        }
                    }
                }
            }
        }
    }

Conclusion

With a few lines of code, you make your application call any method in any type from any module. In combination with code compilation, that is a powerful mechanism to enhance the adaptability of your applications.

References

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Share

About the Author

André Janus
Web Developer
Germany Germany
I am currently student at the university of Karlsruhe and working on my master thesis at the IT-Management and Web Engineering Research Group within the institute of telematics.

Comments and Discussions

 
QuestionWindows Form with TableLayoutPanel is changing its Controls position when is shown in mdiParent Form. How to Resolve this Issue? PinmemberNouman_gcu21-Dec-09 1:16 
GeneralReflection , Invoke Methods using System.Reflection PinmemberNouman_gcu29-Oct-09 3:40 
GeneralMy vote of 2 PinmemberBehrooz_cs29-Jun-09 11:17 
you could use
return Type.getMethod(name,null).Invoke(obj);
 
i think my code is 1/27 your code.
behrooz_cs
QuestionWhat if... PinmemberMember 22902784-Jun-08 23:07 
GeneralGreat article!!. But ... PinmemberSentCleef19-Apr-07 1:24 
GeneralRe: Great article!!. But ... PinmemberAndré Janus19-Apr-07 2:15 
GeneralTotally cool PinmemberMr. VB.NET3-Nov-06 13:13 
GeneralMore Detail Pinmemberqwerty666qwerty66628-Dec-05 5:09 
GeneralRe: More Detail PinmemberD1113-Jun-06 8:41 
GeneralRe: More Detail Pinmembermabxsi18-Aug-06 4:42 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

| Advertise | Privacy | Mobile
Web04 | 2.8.140916.1 | Last Updated 18 Jan 2006
Article Copyright 2005 by André Janus
Everything else Copyright © CodeProject, 1999-2014
Terms of Service
Layout: fixed | fluid