Imports System.Text

Public Class BuildString
    Private Declare Function PostMessage Lib "user32.dll" Alias "PostMessageA" ( _
        ByVal hwnd As Integer, _
        ByVal wMsg As Integer, _
        ByVal wParam As Integer, _
        ByVal lParam As Integer _
    ) As Integer

    Public Event StringOK(ByVal Result As String)
    Private hwnd As Integer = 0
    Private wMsg As Integer = 0
    Private wParam As Integer = 0
    Private lParam As String = ""
    Private tempA() As Byte = New Byte() {}
    Private enc As Encoding = Encoding.UTF8

    Public Property Encode() As Encoding
        Get
            Return enc
        End Get
        Set(ByVal value As Encoding)
            enc = value
        End Set
    End Property

    Public Sub BuildString(ByVal b As IntPtr)
        If b <> 0 Then
            'build temp array
            Dim tempB(tempA.Length) As Byte
            tempA.CopyTo(tempB, 0)
            tempB(tempA.Length) = b
            ReDim tempA(tempB.Length - 1)
            tempB.CopyTo(tempA, 0)
        Else
            'decode byte array to string
            Dim s As String
            If enc Is Encoding.UTF8 Then
                s = Encoding.UTF8.GetString(tempA)
            ElseIf enc Is Encoding.Unicode Then
                s = Encoding.Unicode.GetString(tempA)
            ElseIf enc Is Encoding.ASCII Then
                s = Encoding.ASCII.GetString(tempA)
            Else
                s = Encoding.Default.GetString(tempA)
            End If
            'send out result string via event
            RaiseEvent StringOK(s)
            tempA = New Byte() {} ' Versuch 1, die letzte Nachricht zu löschen ... Fehlgeschlagen
        End If
    End Sub

    Public Sub PostString( _
        ByVal hwnd As Integer, _
        ByVal wMsg As Integer, _
        ByVal wParam As Integer, _
        ByVal lParam As String _
    )
        Dim ba() As Byte
        If enc Is Encoding.UTF8 Then
            ba = Encoding.UTF8.GetBytes(lParam)
        ElseIf enc Is Encoding.Unicode Then
            ba = Encoding.Unicode.GetBytes(lParam)
        ElseIf enc Is Encoding.ASCII Then
            ba = Encoding.ASCII.GetBytes(lParam)
        Else
            ba = Encoding.Default.GetBytes(lParam)
        End If
        Dim i As Integer
        For i = 0 To ba.Length - 1
            PostMessage(hwnd, wMsg, wParam, ba(i))
        Next
        PostMessage(hwnd, wMsg, wParam, 0)
    End Sub
End Class