用VB编个实用小程序

IT商界

黄耀

　　调用屏保

　　以后调用屏保不用再进入显示设置了，现在通过API 函数就可以实现运行屏幕保护的程序；

　　先声明：Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long

　　Const WM_SYSCOMMAND = &H112&

　　Const SC_SCREENSAVE = &HF140&

　　然后加入如下代码到窗体：

　　Private Sub Command1_Click()

　　Dim result As Long

　　result = SendMessage(Form1.hWnd, WM_SYSCOMMAND, SC_SCREENSAVE, 0&)

　　End Sub

　　运行后按下Command1钮即可运行当前屏保程序。

　　改变墙纸

　　在VB中实现以下代码即可：

　　Const SPI_SETDESKWALLPAPER = 20

　　Const SPIF_UPDATEINIFILE = &H1

　　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

　　Call SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, BMP名称, SPIF_UPDATEINIFILE)

　　若想清除桌面墙纸则将BMP名称一项为空。通过它你可以用Timer事件实现桌面的动态更换。