API在VB中应用之技巧集锦[2]

    
     *api函数声明
     const lb_sethorizontalextent = &h194
     private declare function sendmessage lib "user32" alias "sendmessagea" _ (byval hwnd as long, byval wmsg as long, byval wparam as long, _ lparam as any) as long
     注释：调用
     call sendmessage(list1.hwnd, lb_sethorizontalextent, 400, byval 0&)
     注释：注意400是以象素为单位，你可以根据情况自行设定。
    
     9、如何交换鼠标按键？
    
     *api函数声明
     declare function swapmousebutton& lib "user32" _ (byval bswap as long)
     要交换鼠标按键，将bswap参数设置为true。要恢复正常设置，将bswap设置为false。 然后调用函数就可以交换和恢复鼠标按键了。
    
     10、如何让窗体的标题条闪烁以引起用户注意？
    
     在窗体中放一个timer控件timer1,设置其inteval=200
     *api函数声明
     private declare function flashwindow lib "user32" (byval hwnd as long, byval binvert as long) as long
     注释：在窗体中写下如下代码:
     private sub timer1_timer()
     　flashwindow me.hwnd, true
     end sub
    
     11、怎样找到鼠标指针的xy坐标？
    
     *api函数声明
     type pointapi
     x as long
     y as long
     end type
     declare function getcursorpos lib "user32" (lppoint as pointapi) as long
     调用：
     getcursorpos z
     print z.x
     print z.y
    
    
     12、怎样获得和改变双击鼠标的时间间隔？
    
     获得鼠标双击间隔时间：
     public declare function getdoubleclicktime lib "user32" alias _ "getdoubleclicktime" () as long
    
     获得鼠标双击间隔时间：
     declare function setdoubleclicktime lib "user32" alias "setdoubleclicktime" (byval wcount as long) as long
     注释：注意：这种改变将影响到整个操作系统
    
     以上两个函数都可精确到毫秒级。
    
    
     13、在程序中如何打开和关闭光驱门？
    
     *api函数声明如下:
     private declare function mcisendstring lib "winmm.dll" alias "mcisendstringa" (byval lpstrcommand as string, byval lpstrreturnstring as string, byval ureturnlength as long, byval hwndcallback as long) as long
     注释：调用时的代码如下
     dim ret as long
     dim retstr as string
     注释：打开光驱门
     ret = mcisendstring("set cdaudio door open", retstr, 0, 0)
     注释：关闭光驱门
     ret = mcisendstring("set cdaudio door closed", retstr, 0, 0)
    
    
     14、如何获得windows启动方式?
    
     在form1中加入一个commandbutton、一个label并加入如下代码:
     private declare function getsystemmetrics lib "user32" (byval nindex as long) as long
     const sm_cleanboot = 67
    
     private sub command1_click()
     　select case getsystemmetrics(sm_cleanboot)
     　case 1
     　　label1 = "安全模式."
     　case 2
     　　label1 = "支持网络的安全模式."
     　case else
     　　label1 = "windows运行在普通模式."
     　end select
     end sub
    
    
     15、怎样使ctrl-alt-delete无效？
    
     *api函数声明
     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
     编写如下函数：
     sub disablectrlaltdelete(bdisabled as boolean)
     dim x as long
     x = systemparametersinfo(97, bdisabled, cstr(1), 0)
     end sub
     使ctrl-alt-delete无效 ：