add new clipboard watcher class

app/DD_Clipboard_Searcher/ClassClipboardWatcher.vb

@@ -0,0 +1,75 @@
+Imports System.ComponentModel
+Imports System.Runtime.InteropServices
+
+Public Class ClassClipboardWatcher : Inherits NativeWindow : Implements IDisposable
+    <DllImport("user32", EntryPoint:="AddClipboardFormatListener")>
+    Private Shared Function AddClipboardFormatListener(ByVal hWnd As IntPtr) As Boolean
+    End Function
+
+    <DllImport("user32", EntryPoint:="RemoveClipboardFormatListener")>
+    Private Shared Function RemoveClipboardFormatListener(ByVal hWnd As IntPtr) As Boolean
+    End Function
+
+    Public Event Changed As EventHandler(Of String)
+
+    Private ReadOnly _Handle As IntPtr
+    Private _IsDisposed As Boolean = False
+
+    'nur eine globale Instanz zulassen
+    Public Shared Singleton As New ClassClipboardWatcher
+
+    Const WM_CLIPBOARDUPDATE As Integer = &H31D
+
+    Private Sub New()
+        MyBase.CreateHandle(New CreateParams)
+        _Handle = AddClipboardFormatListener(Handle)
+    End Sub
+
+    Protected Overrides Sub WndProc(ByRef m As Message)
+        Select Case m.Msg
+            Case WM_CLIPBOARDUPDATE
+                Dim oWindow = ClassWindowAPI.GetWindowInfo()
+
+                If IsNothing(oWindow.ProcessName) Then
+                    Exit Sub
+                End If
+
+                If oWindow.ProcessName.StartsWith("DD_Clipboard_Watcher") Then
+                    Exit Sub
+                End If
+
+                Dim oText = Clipboard.GetText
+
+                RaiseEvent Changed(Me, oText)
+        End Select
+        MyBase.WndProc(m)
+    End Sub
+
+    Protected Overridable Sub Dispose(ByVal disposing As Boolean)
+        If Not _IsDisposed Then
+            If disposing Then
+                ' TODO: Verwaltete Ressourcen freigeben, wenn sie explizit 
+                ' aufgerufen werden
+            End If
+            MyBase.DestroyHandle()
+            RemoveClipboardFormatListener(_Handle)
+        End If
+        _IsDisposed = True
+    End Sub
+
+    ' Dieser Code wird von Visual Basic hinzugefügt, um das Dispose-Muster 
+    ' richtig zu implementieren.
+    Public Sub Dispose() Implements IDisposable.Dispose
+        ' Sie sollten diesen Code nicht ändern, sondern stattdessen ihren
+        ' Bereinigungscode oben in 
+        ' Dispose(ByVal disposing As Boolean) einfügen.
+        Dispose(True)
+        GC.SuppressFinalize(Me)
+    End Sub
+
+    Protected Overrides Sub Finalize()
+        MyBase.Finalize()
+        Dispose(False)
+    End Sub
+End Class
+