Implementing plugin system with image notifications

Question

Hello Again,

i encountered a new problem. What i wanna do is that i have a plugin system (found over the net) and to be able to use images as notifications from the plugin.

I wrote a weather plugin (TrayGadget) that checks for weather updates in every minute. I have a main wpf window on which i have a stackpanel control (TrayGadgetStack). I want to add the Gadget's IconImage as an image to the stack and i want my gadget to update this image on the main window when the weather (and the matching image) changes. Eg i want to display clouds if the weather is cloudy, but when the sun comes out, i want the image to be changed to a sun image - and the code should be in the plugin's code.

Here's some code:

the plugin interface:

Imports System.Windows.Controls

Public Interface TrayGadget

    Sub LoadFunction()
    Property IconImage() As Image

End Interface
   

Now the WeatherPlugin as follows:

Imports System.Windows.Threading
Imports System.Runtime.InteropServices
Imports System.Windows
Imports System.Windows.Media.Imaging
Imports System.Xml
Imports System.Windows.Controls

Public Class TrayGadget

    Implements TrayGadgetInterface.TrayGadget

    Dim timer As New System.Windows.Threading.DispatcherTimer
    Dim _IconImage As New Image
    
    Private Sub Update()
         'do the update of the current conditions and get the image that matches, raise and image changed event to be able to change the image on the parent form
    End Sub

   Private Sub TimerTick(ByVal sender As Object, ByVal e As System.EventArgs)
        Try
            Me.Update()
        Catch ex As Exception
            Me.IconImageSource = My.Application.Info.DirectoryPath & "\images\no_network.png"
        End Try
    End Sub

    Public Sub LoadFunction() Implements TrayGadgetInterface.TrayGadget.LoadFunction
        IconImageSource = "1.png"
        Me.timer.Interval = New TimeSpan(0, 1, 0)
        AddHandler timer.Tick, AddressOf TimerTick
        timer.Start()
        Update()
    End Sub

   Property IconImage() As Image Implements TrayGadgetInterface.TrayGadget.IconImage
        Get
            Return _IconImage
        End Get
        Set(ByVal value As Image)
            _IconImage = value
        End Set
    End Property

End Class

and this is how i call the plugin:

 Private Function RunGadget(ByVal path As String)
        Dim Gadget As TrayGadgetInterface.TrayGadget = LoadGadget(path)
        If Gadget IsNot Nothing Then
            Gadget.LoadFunction()
            Me.TrayGadgetStack.Children.Add(Gadget.IconImage)
        End If
End Function

Private Function LoadGadget(ByVal LoadPath As String) As TrayGadgetInterface.TrayGadget
        Dim NewGadget As TrayGadgetInterface.TrayGadget
        Try
        Dim PlugInAssembly As Reflection.Assembly = Reflection.Assembly.LoadFrom(LoadPath)
        Dim Types() As Type
        Dim FoundInterface As Type
        Types = PlugInAssembly.GetTypes
        For Each GadgetType As Type In Types
            FoundInterface = GadgetType.GetInterface("TrayGadgetInterface.TrayGadget")
            If FoundInterface IsNot Nothing Then
                NewGadget = DirectCast(PlugInAssembly.CreateInstance(GadgetType.FullName), TrayGadgetInterface.TrayGadget)
            End If
        Next
        Catch ex As Exception
             'handle exceptions here
        End Try
        Return NewGadget
    End Function

Thanks a lot

---

Attila Fogel

Answer 1

Try WPF forum http://social.msdn.microsoft.com/Forums/en-US/wpf/threads

kaymaf

---

If that what you want, take it. If not, ignored it and no complain

Answer 2

Hi Attila Fogel,

The basic scenario here is that you need to refresh the image notification when the weather changes, based on my experience, when you change the data(weather), you raise a event to inform the image to update its source, doing this way, the image notification will be updated according to the weather.

Thanks.
Sincerely.

---

Jim Zhou -MSFT

Answer 3

Hi Attila Fogel,

Have you tried the suggestion I posted above?Did that make sense in your scenario? If you still have any issues with this, please feel free to feed back.

Thanks.
Sincerely.

---

Jim Zhou -MSFT

Answer 4

Hey,

sorry for not posting till now, but yeah, i figured it out by myself, and what you mention is exactly what i'm doing. :) thnx

---

Attila Fogel

Answer 5

Hi Attila Fogel,

Glad to see that your issue was resolved yet, any questions regarding WPF, please feel free to post on this forum, then we can discuss it.

Thanks.
Sincerely.

---

Jim Zhou -MSFT