Guest Author: Jay Roxe

Here is some Visual Basic 2005 code for setting the Windows desktop wallpaper to an arbitrary image on the user's local drive. It illustrates use of VB2005 My classes, in this case to find the location of the user's My Pictures directory without a lot of coding.

To use, paste the following code into the top of your class module. This code requires Visual Basic 2005 to work.

Private Const SPI_SETDESKWALLPAPER As Integer = &H14
Private Const SPIF_UPDATEINIFILE As Integer = &H1
Private Const SPIF_SENDWININICHANGE As Integer = &H2

Private Declare Auto Function SystemParametersInfo Lib "user32.dll" ( _
    ByVal uAction As Integer, ByVal uParam As Integer, _
    ByVal lpvParam As String, ByVal fuWinIni As Integer) As Integer

' change this to whatever filename you want to use
Const WallpaperFile As String = "MovieCollectionImage.bmp"

''' <SUMMARY>
''' Sets the background of your Windows desktop.  
''' The image will be saved in MyPictures and the background 
''' wallpaper updated.
''' </SUMMARY>
''' The image to be set as the background.
''' <REMARKS></REMARKS>
Friend Sub SetWallpaper(ByVal img As Image)
    Dim imageLocation As String
    imageLocation = My.Computer.FileSystem.CombinePath( _
        My.Computer.FileSystem.SpecialDirectories.MyPictures, WallpaperFile)
    Try
        img.Save(imageLocation, System.Drawing.Imaging.ImageFormat.Bmp)
        SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, imageLocation, _
            SPIF_UPDATEINIFILE Or SPIF_SENDWININICHANGE)
    Catch Ex As Exception
        MsgBox("There was an error setting the wallpaper: " & Ex.Message)
    End Try
End Sub

Now, use the following code to set the wallpaper to the desired image. This example shows how to set the wallpaper to an image contained in a Windows Forms picture box:

    SetWallpaper (Me.PictureBox1.Image)

And here's the code in C# as well (requires Visual C# 2005 to work):

private const int SPI_SETDESKWALLPAPER = 0X14;
private const int SPIF_UPDATEINIFILE = 0X1;
private const int SPIF_SENDWININICHANGE = 0X2;

[DllImport("USER32.DLL",EntryPoint="SystemParametersInfo", SetLastError = true)]
private static extern int SystemParametersInfo(int uAction, int uParam, string lpvParam, int fuWinIni);

// change this to whatever filename you want to use
private const string WallpaperFile = "MovieCollectionImage.bmp";

// <SUMMARY>
// Sets the background of your Windows desktop.  
// The image will be saved in MyPictures and the background 
// wallpaper updated.
// </SUMMARY>
// The image to be set as the background.
// <REMARKS></REMARKS>
internal void SetWallpaper(Image img)
{
  string imageLocation;
  imageLocation = System.IO.Path.GetFullPath(System.Environment.SpecialFolder.MyPictures.ToString() + WallpaperFile);
  try
  {
    img.Save(imageLocation, System.Drawing.Imaging.ImageFormat.Bmp);
    SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, imageLocation, SPIF_UPDATEINIFILE | SPIF_SENDWININICHANGE);
  }

  catch (Exception Ex)
  {
    MessageBox.Show("There was an error setting the wallpaper: " + Ex.Message);
  }
}