using System . Runtime . InteropServices;
[ DllImport ( "user32.dll" )]
public static extern int SystemParametersInfo( int uAction ,
int uParam, string lpvParam, int fuWinIni);
public const int SPI_SETDESKWALLPAPER = 20 ;
public const int SPIF_UPDATEINIFILE = 1 ;
public const int SPIF_SENDWININICHANGE = 2 ;
private void button1_Click( object sender , EventArgs e)
{
SystemParametersInfo(SPI_SETDESKWALLPAPER, 0 ,
@"C:\WINDOWS\Zapotec.bmp" ,
SPIF_UPDATEINIFILE | SPIF_SENDWININICHANGE);
}