使用Windows消息控制Winamp（VB）[3]

if hwndwinamp = 0 then '判断winamp是否运行
   msgbox "请启动winamp先！"
   unload me
end if
end sub

2.wm_user 消息：

例程：得到winamp的版本
新建一个标准exe工程，加入一个模块，在模块中加入代码----------

option explicit
public declare function findwindow lib "user32" alias "findwindowa" (byval lpclassname as string, byval lpwindowname as string) as long
'这是vb的api声明，不会返回正确的结果
'public declare function sendmessage lib "user32" alias "sendmessagea" (byval hwnd as long, byval wmsg as long, byval wparam as long, lparam as any) as long

'这是正确的sendmessage声明，才能返回版本信息，读者可以参考一下两者的不同
public 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_user = &h400
const wa_getversion = 0
public hwndwinamp as long                   'winamp的句柄

function winampgetversion() as string
dim versionnum as long
dim returnversion as string
versionnum = sendmessage(hwndwinamp, wm_user, 0, wa_getversion)

if len(hex(versionnum)) > 3 then
   returnversion = left(hex(versionnum), 1) & "."
   returnversion = returnversion & mid(hex(versionnum), 2, 1)
   returnversion = returnversion & right$(hex(versionnum), len(hex(versionnum)) - 3)
   winampgetversion = returnversion
else
   winampgetversion = "unknown"
end if
end function

在form中加入的代码----------

option explicit

private sub command1_click()
msgbox "你的winamp的版本是：" & winampgetversion
end sub

private sub form_load()
hwndwinamp = findwindow("winamp v1.x", vbnullstring) '得到winamp的句柄
if hwndwinamp = 0 then '判断winamp是否运行
   msgbox "请启动winamp先！"
   unload me
end if
end sub

3.wm_copydata 消息：

例程：winamp的运行时刻在播放列表中加入一首mp3的歌曲
新建一个标准exe工程，加入一个模块，在模块中加入代码----------

option explicit

public declare function findwindow lib "user32" alias "findwindowa" (byval lpclassname as string, byval lpwindowname as string) as long
private declare function lstrcpy lib "kernel32" alias "lstrcpya" (byval lpstring1 as string, byval lpstring2 as string) as long
private declare function copydatasendmessage lib "user32" alias "sendmessagea" (byval wndid as long, byval wmsg as long, byval wparam as long, byref lparam as copydatastruct) as long
private type copydatastruct
    dwdata as long
    cbdata as long
    lpdata as long
end type

const ipc_playfile = 100
const wm_copydata = &h4a

public hwndwinamp as long

public sub winampaddsong(songname as string)
dim cds as copydatastruct
with cds
      .dwdata = ipc_playfile
      .cbdata = 100
      .lpdata = lstrcpy(songname, songname)
end with
copydatasendmessage hwndwinamp, wm_copydata, 0&, cds
end sub

在form中加入的代码----------

option explicit

private sub command1_click()
winampaddsong "i:\mp3\周杰伦-简单爱.mp3" '加入一首歌
end sub

private sub form_load()
hwndwinamp = findwindow("winamp v1.x", vbnullstring) '得到winamp的句柄
if hwndwinamp = 0 then '判断winamp是否运行
   msgbox "请启动winamp先！"
   unload me
end if
end sub

所有例程在 win2000 + vb6 中调试通过