Change desktop background

Set the following properties of the form


Text = "Set Wallpaper"
Size = “1024,750”
Now drip a picture box control on the form and set its following properties.


Size = “1024,725”
Sizemode = ”centerimage”
Drop a two button controls on the form and set its following properties as below.


First button control.

Name = " btgetimage"
Text = " Brows For Image"

Second button control.

Name = " btsetwallpaper"
Text = " Set Wallpaper"

Now drop an openfiledialog control on the form. 
Open you code window and import the following namespace.


Imports System.IO.Directory


Now declare the function and variables as below which will use win API's to set the wallpaper.


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

Const WallpaperFile As String = "c:\wallpaper.bmp"


Make a function as below.


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 in the click event of the first button write the following code to open and get the image.

OpenFileDialog1.InitialDirectory = "c:\"

OpenFileDialog1.Filter = "JPG|*.jpg|Bitmap|*.bmp"

Dim dialogresult As DialogResult = OpenFileDialog1.ShowDialog

If dialogresult = Windows.Forms.DialogResult.OK Then

PictureBox1.ImageLocation = OpenFileDialog1.FileName

btsetwallpaper.Enabled = True

End If