Imports System.IO
Imports System.Collections.Generic
Imports System.Drawing
 
Public Class Form1
    Declare Function ShowCursor Lib "user32" (ByVal bShow As Boolean) As Long
    Dim CursorHidden As Boolean
    Dim files As New List(Of FileInfo)
    Dim ActIndex As Integer
 
    Private Sub Form1_FormClosed(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.FormClosedEventArgs) Handles Me.FormClosed
        If CursorHidden Then ShowCursor(True)
    End Sub
 
    Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        If e.CloseReason = CloseReason.ApplicationExitCall Then Exit Sub
        If MessageBox.Show("Beenden?", "[TYFOO]:.", MessageBoxButtons.YesNo, _
          MessageBoxIcon.Information, MessageBoxDefaultButton.Button1) = _
          Windows.Forms.DialogResult.No Then
            e.Cancel = True
        End If
    End Sub
 
    Private Sub Form1_KeyDown(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown
        Select Case e.KeyCode
            Case Keys.Right
                ActIndex += 1
                If ActIndex >= files.Count Then ActIndex = 0
                ShowAct()
            Case Keys.Left
                ActIndex -= 1
                If ActIndex < 0 Then ActIndex = files.Count - 1
                ShowAct()
            Case Keys.Escape
                Me.Close()
        End Select
    End Sub
    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) _
      Handles Me.Load
        pic.Top = 0
        pic.Left = 0
        pic.Height = Me.ClientRectangle.Height
        pic.Width = Me.ClientRectangle.Width
        Dim Folder As New DirectoryInfo(Application.StartupPath)
        files.AddRange(Folder.GetFiles("*.jpg"))
        files.AddRange(Folder.GetFiles("*.png"))
        files.AddRange(Folder.GetFiles("*.gif"))
        files.AddRange(Folder.GetFiles("*.bmp"))
        files.Sort(New FileComparer)
        If files.Count = 0 Then
            MsgBox("Es wurden keine Bilddateien gefunden!", "Fehler", _
              MessageBoxIcon.Error)
            Application.Exit()
        End If
        ShowAct()
 
    End Sub
    Public Sub ShowAct()
        pic.Image = Image.FromFile(files(ActIndex).FullName)
    End Sub
 
    Private Sub bt_close_Paint(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.PaintEventArgs) Handles bt_close.Paint
        bt_close.BackColor = Color.Transparent
        bt_close.Parent = pic
    End Sub
 
    Private Sub bt_next_Paint(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.PaintEventArgs) Handles bt_next.Paint
        bt_next.BackColor = Color.Transparent
        bt_next.Parent = pic
    End Sub
 
    Private Sub bt_prev_Paint(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.PaintEventArgs) Handles bt_prev.Paint
        bt_prev.BackColor = Color.Transparent
        bt_prev.Parent = pic
    End Sub
 
    Private Sub bt_close_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles bt_close.Click
        Me.Close()
    End Sub
 
    Private Sub bt_next_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles bt_next.Click
        ActIndex += 1
        If ActIndex >= files.Count Then ActIndex = 0
        ShowAct()
    End Sub
 
    Private Sub bt_prev_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles bt_prev.Click
        ActIndex -= 1
        If ActIndex < 0 Then ActIndex = files.Count - 1
        ShowAct()
    End Sub
 
End Class
 
Public Class FileComparer
    Implements IComparer(Of FileInfo)
    Public Function Compare(ByVal x As System.IO.FileInfo, ByVal y As _
      System.IO.FileInfo) As Integer Implements _
      System.Collections.Generic.IComparer(Of System.IO.FileInfo).Compare
        Return x.Name < y.Name
    End Function
 
End Class

[TYFOO]:.