Interfaces

[ngreenwood6]

I have the following code:

Imports System
Imports System.Collections.Generic
Imports System.Drawing
Imports System.Linq
Imports System.Windows.Forms
Imports System.ComponentModel.Composition
Imports System.ComponentModel.Composition.Hosting
Imports Interfaces
Imports System.Text

Namespace DemoPlugInTwo
    <Export(GetType(IPlugins))> _
    Public Class DemoPlugInTwo
        Implements IPlugins

        Public Sub createControl(ByRef myPanel As Panel)
            Dim myButton As New Button()
            myButton.Text = "Click Me!"
            AddHandler myButton.Click, AddressOf myButton_Click
            myPanel.Controls.Add(myButton)
        End Sub

        Public Sub myButton_Click(ByVal sender As Object, ByVal e As EventArgs)
            MessageBox.Show("Hey Kevin")
        End Sub

        Public ReadOnly Property name() As String
            Get
                Return "Demo Plugin Three"
            End Get
        End Property

        Public ReadOnly Property version() As String
            Get
                Return "Version 5.0"
            End Get
        End Property

    End Class
End Namespace

but I am getting this error:

Error 1 Class 'DemoPlugInTwo' must implement 'ReadOnly Property name() As String' for interface 'Interfaces.IPlugins'. Implementing property must have matching 'ReadOnly' or 'WriteOnly' specifiers. C:\Documents and Settings\Owner\My Documents\Visual Studio 2008\Projects\DemoPlugInThree\DemoPlugInThree\DemoPlugInThree.vb 14 20 DemoPlugInThree

I am getting similiar errors for the other property and method. I have them set as read only. Any ideas?

[jmcilhinney]

Just because you have members with those names doesn't mean that they implement the corresponding members from the interface. What you should ALWAYS do is hit <Enter> immediately after the "Implements SomeInterface" line and the IDE will add the skeleton code for you, including the "Implements" clause on each member. If you want to do it for yourself then you need to add the "Implements" clause yourself, e.g.

Public ReadOnly Property name() As String Implements IPlugins.name

Also, while what you do is up to you it really makes no sense to me to not follow .NET coding conventions without very good reason. Those conventions dictate that property names start with an upper case character. Unless you have a good reason not to, you should follow that convention.

[ngreenwood6]

Thanks that worked perfectly. I am used to programming in c# but I was seeing if I could implement a plugin in visual basic. In c# you dont have to do that. I have a question for you though. In c# if I go to this line:

Public Class DemoPlugInTwo
        Implements IPlugins

and hover over the IPlugins word and right click I can select implement interface. Is there a way to do that in vb?

[jmcilhinney]

There is an equivalent in VB:

hit <Enter> immediately after the "Implements SomeInterface" line

In C# you have the choice of implementing or explicitly implementing. As far as I'm aware, VB doesn't support explicit implementation so there's no need for VB to wait for you to choose as there is in C#.

[boldyak]

Hi. I'm having the same error in spite of following the correct procedure and letting .NET automatically create for me the necessary skeleton of the interface property implementation in my code behind (i.e. I press Enter after the "Implements" line and .NET creates the code skeleton of the interface properties at the bottom of the class block). I found in microsoft that this was actually a bug in VS2005 and there was a fix given there (http://support.microsoft.com/kb/316581) but I don't think the fix can be applied to VS 2008.

I can't fix the darn thing. I've tried the following actions with no success:
1. I did a "Rebuild" on the project where my IView or interface and presenter were defined, then a rebuild on my Web site, then a rebuild on my whole solution.
2. I tried to create a new IView and Presenter and then re-wired my code behind to consume these classes but ran into the same error.

Any thoughts and possible resolution? I'm at my wits end.