VB怎样更改电脑桌面违景为拉，请写下详细代码。


添加三个命令按钮，1个PictureBox，1个CommonDialog控件
代码如次：
Private Declare Function SystemParametersInfo Lib "user32" Alias "SystemParametersInfoA" (ByVal uAction As Long, ByVal uParam As Long, _
ByVal lpvParam As Any, ByVal fuWinIni As Long) As Long
""方式设置为墙纸
Private Const SPI_SETDESKWALLPAPER = 20
""将新的设置写入用户文件中，&H1=1
Private Const SPIF_UPDATEINIFILE = &H1

Dim PicName As String

""打开图片文件
Private Sub Command1_Click()
""创建打开文件对于话框
With CommonDialog1
.Filter = "bmp文件(*.bmp)|*.bmp"
.ShowOpen
""获患上图片文件名称
PicName = .FileName
End With
""预览图片
Picture1.Picture = LoadPicture(PicName)
""判断是否打开文件
If PicName = "" Then Exit Sub
End Sub

""设置墙纸
Private Sub Command2_Click()
Dim SysInfo As Long
""设置指定图片为桌面墙纸
SysInfo = SystemParametersInfo(SPI_SETDESKWALLPAPER, True, PicName, SPIF_UPDATEINIFILE)
""判断设置是否成功
If SysInfo = 0 Then
MousePointer = 0
MsgBox "很抱歉，不能安装此类墙纸"
Else
MsgBox "恭喜你，成功地安装了墙纸"
End If
End Sub

""退出程序
Private Sub Command3_Click()
End
End Sub

Private Sub Picture1_Change()
Me.Width = Picture1.Width
Me.Height = Picture1.Height * 1.2
End Sub