Comments on: How To Create Application Plug-ins In VB.NET http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/ Articles on VB.NET and Software Development Team Leadership Mon, 15 Mar 2010 23:42:13 +0000 http://wordpress.org/?v=2.7.1 hourly 1 By: Samsonov http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/comment-page-1/#comment-1387 Samsonov Mon, 17 Aug 2009 10:17:23 +0000 http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/#comment-1387 Those techniques with GetType / GetInterface are "not CLS-compliant" (as VB help claims). There is a more easier and graceful way to do things — just to create objects by their class name, not by an abstract interface type. Of course, it assumes that the plugin is a class library, but I think that's the case in the majority of situations. For example, plugin's code: <code>Public Class MyPluginImplementation Inherits MyPluginBase .....{code must include constructor with no arguments}..... End Class</code> And the application code: <code>Dim oAssembly As Reflection.Assembly = Reflection.Assembly.LoadFrom(sFile) Dim oInstance As MyPluginBase = DirectCast(oAssembly.CreateInstance("RootNamespace.Namespace.MyPluginImplementation"), MyPluginBase) If Not IsNothing(oInstance) Then .....{do something}.....</code> Those techniques with GetType / GetInterface are “not CLS-compliant” (as VB help claims). There is a more easier and graceful way to do things — just to create objects by their class name, not by an abstract interface type. Of course, it assumes that the plugin is a class library, but I think that’s the case in the majority of situations.

For example, plugin’s code:

Public Class MyPluginImplementation Inherits MyPluginBase
.....{code must include constructor with no arguments}.....
End Class

And the application code:

Dim oAssembly As Reflection.Assembly = Reflection.Assembly.LoadFrom(sFile)
Dim oInstance As MyPluginBase = DirectCast(oAssembly.CreateInstance("RootNamespace.Namespace.MyPluginImplementation"), MyPluginBase)
If Not IsNothing(oInstance) Then .....{do something}.....

]]> By: yousif http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/comment-page-1/#comment-1376 yousif Tue, 14 Jul 2009 16:53:42 +0000 http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/#comment-1376 thanks allot !! i get the main idea but the question is how do i know that the plug-in would not do any bad thing to my app ?? thanks allot !!

i get the main idea

but the question is how do i know that the plug-in would not do any bad thing to my app ??

]]> By: leizel http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/comment-page-1/#comment-1302 leizel Thu, 22 Jan 2009 01:29:45 +0000 http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/#comment-1302 hi, can you show me an example of program of for loop and if else for vb6. hi,
can you show me an example of program of for loop and if else for vb6.

]]> By: Jouke http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/comment-page-1/#comment-1196 Jouke Mon, 01 Sep 2008 09:29:11 +0000 http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/#comment-1196 Is it possible for the plugin to get info from the host? Is it possible for the plugin to get info from the host?

]]> By: Mike http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/comment-page-1/#comment-993 Mike Tue, 29 Jan 2008 19:28:52 +0000 http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/#comment-993 Doesn't the assembly remain loaded though? I'd like to be able to update the plug-in while my program is still running. Can you not just reference a DLL and achieve the same effect? Doesn’t the assembly remain loaded though? I’d like to be able to update the plug-in while my program is still running.
Can you not just reference a DLL and achieve the same effect?

]]> By: jfrankcarr http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/comment-page-1/#comment-854 jfrankcarr Mon, 05 Nov 2007 16:47:32 +0000 http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/#comment-854 Hi Karl, Check out my new post: <a href="http://vbnotebookfor.net/2007/11/05/application-plug-ins-code-example-update/" rel="nofollow">Application Plug-ins Code Example Update</a>. Follow the instructions in that article and you should be good to go. Hi Karl,

Check out my new post: Application Plug-ins Code Example Update. Follow the instructions in that article and you should be good to go.

]]> By: Karl Stoney http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/comment-page-1/#comment-852 Karl Stoney Mon, 05 Nov 2007 12:31:34 +0000 http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/#comment-852 Hi, This is really great i've been searching for somthing like this for ages, but i'm still having difficulty grasping reflection, would you send me an example project + plugin ? I would really appreciate it. Karl. Hi,
This is really great i’ve been searching for somthing like this for ages, but i’m still having difficulty grasping reflection, would you send me an example project + plugin ? I would really appreciate it.

Karl.

]]> By: jfrankcarr http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/comment-page-1/#comment-736 jfrankcarr Wed, 10 Oct 2007 18:56:40 +0000 http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/#comment-736 Yes, it will work for web apps. You do have to be more mindful of the performance hit though. It can be particularly effective for background processes called from a web interface or through a web service. This can allow you to add additional services for specific customers easily. As for keeping up with the DLLs I store the location of a client's specific DLL in their account record in the DB. Yes, it will work for web apps. You do have to be more mindful of the performance hit though. It can be particularly effective for background processes called from a web interface or through a web service. This can allow you to add additional services for specific customers easily.

As for keeping up with the DLLs I store the location of a client’s specific DLL in their account record in the DB.

]]> By: MikeP http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/comment-page-1/#comment-735 MikeP Wed, 10 Oct 2007 16:22:18 +0000 http://vbnotebookfor.net/2007/10/09/how-to-create-application-plug-ins-in-vbnet/#comment-735 Will this work for web apps too? How do you keep up with which DLL you need to load in a situation? Will this work for web apps too?

How do you keep up with which DLL you need to load in a situation?

]]>