Plugin mit DLLs

GiCo

Neuer Benutzer

Join Date: 27.08.2007
Posts: 1

27.08.2007, 19:15

Hallo Leute,

Ich probier zur Zeit mich mit dlls vertraut zu machen und probiere mit Hilfe von ihnen ein Pluginsystem zu entwickeln. Ich habe eine sehr gutes Tutorial von Fabian Stern gelesen, was mich schon sehr weit gebracht hat im Verst�ndnis von dlls im Bezug auf Plugins.
Meine Frage w�re wie kann ich es schaffen, dass ich auf das Hauptprogramm aus den Funktionen des Plugins zugreifen kann, wie es auch die Funktionen des Hauptprogramms k�nnen.
Also umgef�hr so:
myHost.Form1.Button2
myHost.testFunc("Test")

Hier mal das Beispiel aus dem Tutorial

Plugin:

Code:

<Serializable()> Public Class clsPlugin 'Make it creatable on Runtime
    Inherits MarshalByRefObject 'AppDomain Compatibility
    Implements clsPluginLoader.IPlugin 'Link this class to the plugin interface IPlugin

    Dim myHost As clsPluginLoader.IHost

    Public Overrides Function InitializeLifeTimeService() As Object 'Make the plugin-lifetime unlimited (otherwise it will expire)
        Return Nothing
    End Function

    Public Sub SetHost(ByVal mHost As clsPluginLoader.IHost) Implements clsPluginLoader.IPlugin.SetHost
        myHost = mHost 'Set a link to objects of the main-application
    End Sub
    Public Function GetName() As String Implements clsPluginLoader.IPlugin.GetName 'Get the plugin name
        Return "MyPlugin by Timo Wiegel2"
    End Function
    Public Sub Load() Implements clsPluginLoader.IPlugin.Load 'When the plugin is loaded
        System.Windows.Forms.MessageBox.Show("Plugin is loaded 4Plugin")
    End Sub
    Public Sub Unload() Implements clsPluginLoader.IPlugin.Unload 'When the plugin is unloaded
        System.Windows.Forms.MessageBox.Show("Plugin is unloaded 4Plugin")
    End Sub
    Public Sub Run() Implements clsPluginLoader.IPlugin.Run
        myHost.myLabel.Text = "Plugin2"
    End Sub
End Class

PluginLoader

Code:

 
Public Interface IPlugin
    Function GetName() As String
    Sub Load()
    Sub Unload()
    Sub Run()
    Sub SetHost(ByVal mHost As IHost)
End Interface

Public Interface IHost
    Function myLabel() As System.Windows.Forms.Label
    Function myForm() As System.Windows.Forms.Form
End Interface

eigentliches Programm

Code:

 
Public Class Form1
    Inherits System.Windows.Forms.Form
    Implements clsPluginLoader.IHost

#Region " Vom Windows Form Designer generierter Code "

    Public Sub New()
        MyBase.New()

        ' Dieser Aufruf ist f�r den Windows Form-Designer erforderlich.
        InitializeComponent()

        ' Initialisierungen nach dem Aufruf InitializeComponent() hinzuf�gen

    End Sub

    ' Die Form �berschreibt den L�schvorgang der Basisklasse, um Komponenten zu bereinigen.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    ' F�r Windows Form-Designer erforderlich
    Private components As System.ComponentModel.IContainer

    'HINWEIS: Die folgende Prozedur ist f�r den Windows Form-Designer erforderlich
    'Sie kann mit dem Windows Form-Designer modifiziert werden.
    'Verwenden Sie nicht den Code-Editor zur Bearbeitung.
    Friend WithEvents Label1 As System.Windows.Forms.Label
    Friend WithEvents lst As System.Windows.Forms.ListBox
    Friend WithEvents Label2 As System.Windows.Forms.Label
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Button2 As System.Windows.Forms.Button
    Friend WithEvents lblAccess As System.Windows.Forms.Label
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.Label1 = New System.Windows.Forms.Label
        Me.lst = New System.Windows.Forms.ListBox
        Me.Label2 = New System.Windows.Forms.Label
        Me.Button1 = New System.Windows.Forms.Button
        Me.Button2 = New System.Windows.Forms.Button
        Me.lblAccess = New System.Windows.Forms.Label
        Me.SuspendLayout()
        '
        'Label1
        '
        Me.Label1.Location = New System.Drawing.Point(8, 8)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(56, 16)
        Me.Label1.TabIndex = 0
        Me.Label1.Text = "Functions:"
        '
        'lst
        '
        Me.lst.Location = New System.Drawing.Point(16, 32)
        Me.lst.Name = "lst"
        Me.lst.Size = New System.Drawing.Size(184, 108)
        Me.lst.TabIndex = 1
        '
        'Label2
        '
        Me.Label2.Location = New System.Drawing.Point(72, 8)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(128, 16)
        Me.Label2.TabIndex = 2
        Me.Label2.Text = "(from plugins/ directory)"
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(16, 144)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(104, 24)
        Me.Button1.TabIndex = 3
        Me.Button1.Text = "Unload All Plugins"
        '
        'Button2
        '
        Me.Button2.Location = New System.Drawing.Point(128, 144)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(72, 24)
        Me.Button2.TabIndex = 4
        Me.Button2.Text = "Reload"
        '
        'lblAccess
        '
        Me.lblAccess.Location = New System.Drawing.Point(216, 8)
        Me.lblAccess.Name = "lblAccess"
        Me.lblAccess.Size = New System.Drawing.Size(344, 160)
        Me.lblAccess.TabIndex = 5
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(568, 171)
        Me.Controls.Add(Me.lblAccess)
        Me.Controls.Add(Me.Button2)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.Label2)
        Me.Controls.Add(Me.lst)
        Me.Controls.Add(Me.Label1)
        Me.Name = "Form1"
        Me.Text = "Main Plugin Form"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Dim mySetup As New AppDomainSetup
    Dim myAppDomain As AppDomain
    Dim myEvidence As System.Security.Policy.Evidence = AppDomain.CurrentDomain.Evidence
    Dim myPlugin() As clsPluginLoader.IPlugin
    Dim bLoaded As Boolean = False

#Region "Free Available Host-Objects"
    Function myLabel() As Label Implements clsPluginLoader.IHost.myLabel
        Return lblAccess
    End Function
#End Region

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Init_Plugins()
    End Sub

    Sub Init_Plugins()
        mySetup.ApplicationBase = System.Environment.CurrentDirectory
        myAppDomain = AppDomain.CreateDomain("AppBase", myEvidence, mySetup)

        ReDim myPlugin(0) 'Create Plugin Space

        If IO.Directory.Exists(Application.StartupPath & "\plugins") Then
            For Each myFile As String In IO.Directory.GetFiles(Application.StartupPath & "\plugins\")
                Dim myPI As Int32 = GetFreePlugin()
                Try
                    myPlugin(myPI) = myAppDomain.CreateInstanceFromAndUnwrap(myFile, "clsPluginSample.clsPlugin") 'Add Plugin to myPlugin variable
                    myPlugin(myPI).SetHost(Me)
                    lst.Items.Add(myPlugin(myPI).GetName) 'Add Plugin Name
                    myPlugin(myPI).Load() 'Execute the Load Sub INSIDE THE PLUGIN
                Catch ex As Exception
                    Try 'On error delete the errorneous plugin
                        myPlugin(myPI) = Nothing
                    Catch
                    End Try
                    MessageBox.Show("Invalid module ignored: " & myFile & " [" & ex.Message & "]")
                End Try
            Next
        End If

        bLoaded = True 'All plugins loaded successfully
    End Sub

    Function GetFreePlugin() As Int32
        For I As Int32 = 0 To myPlugin.GetUpperBound(0)
            If myPlugin(I) Is Nothing Then Return I
        Next
        Dim myUB As Int32 = myPlugin.GetUpperBound(0) + 1
        ReDim Preserve myPlugin(myUB)
        Return myUB
    End Function

    Function GetPlugin(ByVal mName As String) As Int32
        For I As Int32 = 0 To myPlugin.GetUpperBound(0)
            If Not myPlugin(I) Is Nothing Then
                If myPlugin(I).GetName = mName Then Return I
            End If
        Next
        Return -1
    End Function

    Private Sub lst_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lst.SelectedIndexChanged
        Dim myI As Int32 = GetPlugin(CType(lst.SelectedItem, String))
        If myI > -1 Then myPlugin(myI).Run()
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        For I As Int32 = 0 To myPlugin.GetUpperBound(0)
            If Not myPlugin(I) Is Nothing Then
                myPlugin(I).Unload()
                myPlugin(I) = Nothing
            End If
        Next
        If bLoaded Then AppDomain.Unload(myAppDomain) : bLoaded = False
        lst.Items.Clear()
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        If Not bLoaded Then Init_Plugins() : bLoaded = True
    End Sub
End Class

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