CODEWITHSUNDEEP
asp.netvb.netdesign-patterns
w0051977
w0051977

Reputation: 15807

VB.NET - Reusing code in code behind

There is some code in an ASP.NET web application code behind class that I want to reuse in a VB.NET WinForms application. Please see the code below from the code behind (ASP.NET web application (not website)):

Public Class _Default
    Inherits System.Web.UI.Page

    Private Sub button1_Click(sender As Object, e As System.EventArgs) Handles button1.Click
        MsgBox("button1.click")
    End Sub
End Class

and the code behind:

Imports WebApplication1

Public Class TestClass
    Public Shared Sub Test100()
        MsgBox("button clicked on page")
    End Sub
End Class

Public Class Form1

    Public Event BellRings(ByVal sender As Object, ByVal e As EventArgs)
    Public test As String

    public Shared TestMethod()
      MsgBox("Test Method was called")
    End public

    Private Sub Form1_Load(sender As Object, e As System.EventArgs) Handles Me.Load
        Try
            Dim d As WebApplication1._Default = New WebApplication1._Default
            AddHandler d.button1.Click, AddressOf Form1.TestMethod
        Catch ex As Exception

        End Try
    End Sub
End Class

I realise that it would probably be better to create a service layer, which both clients use, however I am wandering if the above is even possible? i.e. is it possible to add an event handler in a WinForm for an event in a web application i.e. button.click?

Upvotes: 0

Views: 1020

Answers (1)

competent_tech
competent_tech

Reputation: 44931

You could potentially get away with this through the creative use of partial classes and referencing the code-behind class from the winforms app.

However, that would be a very fragile implementation. For example, if you wanted to provide the same functionality through a menu or want to change the button control to a third-party vendor's control that does not have the same signature as the winforms control or vice versa.

A much better approach, even without the service layer, would be to move the common functionality into a class that is shared between the two applications and is simply called from the event handler.

Yes, you will have to define event handlers in both apps, but that is a trivial amount of code and also allows you to perform platform-specific error handling (for example, in the web app, you may want to show the exception through a javascript alert while in the winforms app, you may want to show it through a msgbox).

Upvotes: 4

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