[2005] adding / importing references at runtime?

[adshocker]

hi all,

is this possible?

i plan to create a MDI Form for the executable. then use classes for forms. can i reference this classes at runtime?

thanks

[Negative0]

Are you trying to do some sort of plug-in architecture?

You can do what you are asking, I am just trying to understand why you are asking for it.

[adshocker]

Are you trying to do some sort of plug-in architecture?

You can do what you are asking, I am just trying to understand why you are asking for it.

hi,

forgive me but i am not familiar with the plug-in architecture term.

but what i'm trying to do is that for example, i already created the MDI Form which serves as the Main Form. i built this as an exe file. so basically this will be the file to run the application. this mdi form will have a menu that will be created at runtime as well. i will be using a database table to hold the items in the menu. then clicking a menu will basically load a child form.

for all the child forms, i will be using classes.

so instead of editing the whole project when adding child forms, i plan to just create a class for a form then built the .dll file. then copy it to a directory where all the applications .dll resides. then add a record to the table for this particular form.

thanks.

[Negative0]

So you want to load a DLL on the fly and use classes from it?

If so, I have a plug-in example on my website that shows you how to create a plugin architecture in a program. It is in C# and it focuses on a plugin that draws on an image, but you should be able to take that and extrapolate some of the information that you need:

http://johnkoerner.net/index.php?/ar...ture-in-C.html

[adshocker]

i'll check it out.

thanks.

[adshocker]

hi,

i've been trying to follow the video provided on the link. at first i thought it would be easy to convert C# to VB.Net but it seems like its harder than i thought. so after spending some time trying, i'm wanting to give up doing this in C#.Net.

my apologies as i'm not able to follow the instructions on the video. i'm having a hard-time understanding the codes well since i'm a VB.Net programmer and C#.Net is totally alien to me.

do you have a vb.net sample?

thanks.

[Negative0]

The basic steps are the same, don't worry so much about how it is coded in my example:

1.) Create an interface.
2.) Implement that interface in your plugin (or your form in your case)
3.) In your main app, loop through all DLLs in a specific folder and if they implement your interface, add them to a list for use later.
4.) When you are ready, call the plugins method that is implemented in the interface.

Here is a quick example I threw together:

For the interface:
PROJECT1 - The other two projects need a reference to this project.

Public Interface TestInterface
    Sub DoWork(ByVal f As Form)
End Interface

In my class that implements the interface:
PROJECT2

Imports InterfaceTesting
Imports System.Windows.Forms
Public Class Class1
    Implements TestInterface


    Public Sub DoWork(ByVal f As Form) Implements InterfaceTesting.TestInterface.DoWork
        Dim myForm As New Form1
        myForm.MdiParent = f
        myForm.Show()
    End Sub
End Class

PROJECT3
In my program that loads the plugins:

Imports System.Reflection
Imports InterfaceTesting
Public Class Form1

    Dim Plugs As List(Of TestInterface)
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        For Each p As TestInterface In Plugs
            p.DoWork(Me)
        Next
    End Sub

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Me.IsMdiContainer = True
        Plugs = New List(Of TestInterface)

        Dim files() As String = IO.Directory.GetFiles(Application.StartupPath & "\Plugins", "*.dll")
        Dim assm As Assembly
        For Each f As String In files
            assm = Assembly.LoadFile(f)
            For Each t As Type In assm.GetTypes()
                If Not t.GetInterface("TestInterface") Is Nothing Then
                    Dim plugin As TestInterface = DirectCast(Activator.CreateInstance(t), TestInterface)
                    Plugs.Add(plugin)
                End If
            Next
        Next
    End Sub
End Class

[adshocker]

thanks for the detailed sample... found it really helpful. i'm able to load forms now using this.

so basically as long as i load the form, each and every event in the form will work like when invoked the usual way?

[Negative0]

Yes, just remember everything that is being done is in the class, not your main application, so if you need to communicate between forms, you are going to have to do a little bit more work.

[adshocker]

thanks...

i was just thinking that if two of my forms needed to communicate, maybe i should put both forms in one class instead as long as the forms are related to each other like a master-detail form? or is there any better way?

since i think there will be situations that forms will need to communicate.

[adshocker]

hi again,

i'm having the need to have my forms (not in same class) to communicate with each other. unfortunately i don't know how i can accomplish this.

can someone help me?

thanks