This is a Simple Wallpaper Manager that allows you to select image files from a location on your computer and build saveable lists of local wallpaper image files that can then be loaded in to the application to save browse time. Automatic wallpaper cycle allows you to configure automatic wallpaper change every hour, daily, weekly, or monthly.

Code:

Public Class FormMain


    Dim w As IO.StreamWriter 'saving list
    Dim r As IO.StreamReader 'loading list

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles btnLoad.Click

        'Select our wallpaper image files for list and preview images.
        If OpenFileDialog1.ShowDialog() = DialogResult.OK Then
            PictureBox1.Load(OpenFileDialog1.FileName)
        End If

        Dim file As String

        'Build wallpaper list.
        For Each file In OpenFileDialog1.FileNames
            ListBox1.Items.Add(file)
        Next

    End Sub

    Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged

        'Manually cycle through list previews.
        PictureBox1.ImageLocation = (Me.ListBox1.SelectedItem)

    End Sub

    Private Sub btnDelete_Click(sender As System.Object, e As System.EventArgs) Handles btnDelete.Click

        'Remove selected image files from list.
        ListBox1.Items.Remove(ListBox1.SelectedItem)

    End Sub



    Private Sub btnSet_Click(sender As System.Object, e As System.EventArgs) Handles btnSet.Click

        'Open wallpaper setting dialog.
        Dim thirdform As New FormSelect
        thirdform.Show()

    End Sub

    Private Sub btnSave_Click(sender As System.Object, e As System.EventArgs) Handles btnSave.Click

        'Save current wallpaper list.
        Dim i As Integer
        If SaveFileDialog1.ShowDialog() = Windows.Forms.DialogResult.OK Then
            w = New IO.StreamWriter(SaveFileDialog1.FileName)
            For i = 0 To ListBox1.Items.Count - 1
                w.WriteLine(ListBox1.Items.Item(i))
            Next
            w.Close()
            MsgBox("List saved to" + SaveFileDialog1.FileName)
        End If
    End Sub

    Private Sub Button1_Click_1(sender As System.Object, e As System.EventArgs) Handles btnLoadList.Click

        'Load wallpaper list.
        If OpenFileDialog2.ShowDialog() = DialogResult.OK Then
            ListBox1.Items.Clear()
            r = New IO.StreamReader(OpenFileDialog2.FileName)
            While (r.Peek() > -1)
                ListBox1.Items.Add(r.ReadLine)
            End While
            r.Close()
        End If

    End Sub

    Private Sub btnClear_Click(sender As System.Object, e As System.EventArgs) Handles btnClear.Click

        'Clear current wallpaper list.
        ListBox1.Items.Clear()

    End Sub

    Private Sub btnOpt_Click(sender As System.Object, e As System.EventArgs) Handles btnOpt.Click

        Dim fourthform As New FormOpt
        fourthform.Show()
        Me.Hide()

    End Sub


    'Start Menu Strip Procedures.

    Private Sub BrowseToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles BrowseToolStripMenuItem.Click
        If OpenFileDialog1.ShowDialog() = DialogResult.OK Then
            PictureBox1.Load(OpenFileDialog1.FileName)
        End If
        Dim file As String
        For Each file In OpenFileDialog1.FileNames
            ListBox1.Items.Add(file)
        Next
    End Sub
    Private Sub LoadListToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles LoadListToolStripMenuItem.Click
        If OpenFileDialog2.ShowDialog() = DialogResult.OK Then
            ListBox1.Items.Clear()
            r = New IO.StreamReader(OpenFileDialog2.FileName)
            While (r.Peek() > -1)
                ListBox1.Items.Add(r.ReadLine)
            End While
            r.Close()
        End If
    End Sub
    Private Sub SetSelectedWallpaperToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles SetSelectedWallpaperToolStripMenuItem.Click
        Dim thirdform As New FormSelect
        thirdform.Show()
    End Sub
    Private Sub SaveListToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles SaveListToolStripMenuItem.Click
        Dim i As Integer
        If SaveFileDialog1.ShowDialog() = Windows.Forms.DialogResult.OK Then
            w = New IO.StreamWriter(SaveFileDialog1.FileName)
            For i = 0 To ListBox1.Items.Count - 1
                w.WriteLine(ListBox1.Items.Item(i))
            Next
            w.Close()
            MsgBox("List saved to" + SaveFileDialog1.FileName)
        End If
    End Sub
    Private Sub DeleteSelectedToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles DeleteSelectedToolStripMenuItem.Click
        ListBox1.Items.Remove(ListBox1.SelectedItem)
    End Sub



End Class

Imports Microsoft.Win32
Imports System.Environment
Imports System.Drawing.Imaging
Imports System.ComponentModel
Imports System.Runtime.InteropServices

Public Class FormSelect

    'Declarations for wallpaper set procedure.
    Private Declare Function SystemParametersInfo Lib "user32" Alias "SystemParametersInfoA" (ByVal uAction As Integer, ByVal uParam As Integer, ByVal lpvParam As String, ByVal fuWinIni As Integer) As Integer
    Private Const SETDESKWALLPAPER As Integer = &H14
    Private Const UPDATEINIFILE = &H1
    Private Const SPIF_SENDWININICHANGE = &H2
    'End set procedure Declarations.

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click

        'Assign list data from list generated in FormMain.
        Dim listdata As String
        listdata = FormMain.PictureBox1.ImageLocation
        'Declare registry section to be edited for wallpaper size mode.
        Dim key As RegistryKey = Registry.CurrentUser.OpenSubKey("Control Panel\Desktop", True)

        'Check to verify a size mode has been selected. If false, alert user and exit code sub.
        'If true, edit registry keys for selected size mode and run wallpaper set procedure.
        If CheckBox1.CheckState = CheckState.Unchecked And
            CheckBox2.CheckState = CheckState.Unchecked And
            CheckBox3.CheckState = CheckState.Unchecked Then
            MsgBox("Please select a size option.")

            Exit Sub

        ElseIf CheckBox1.CheckState = CheckState.Checked Then
            key.SetValue("WallpaperStyle", "2")
            key.SetValue("TileWallpaper", "0")
            SystemParametersInfo(SETDESKWALLPAPER, 0, listdata, UPDATEINIFILE)
        ElseIf CheckBox2.CheckState = CheckState.Checked Then
            key.SetValue("WallpaperStyle", "0")
            key.SetValue("TileWallpaper", "0")
            SystemParametersInfo(SETDESKWALLPAPER, 0, listdata, UPDATEINIFILE)
        ElseIf CheckBox3.CheckState = CheckState.Checked Then
            key.SetValue("WallpaperStyle", "0")
            key.SetValue("TileWallpaper", "1")
            SystemParametersInfo(SETDESKWALLPAPER, 0, listdata, UPDATEINIFILE)
        End If

        Me.Close()

    End Sub

    Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click

        Me.Close()

    End Sub

End Class