VB后台按键

VB如何实现后台按键 (F4)
发个完整的编码来，谢谢

Private Declare Function PostMessage Lib "user32" Alias "PostMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function GetWindowThreadProcessId Lib "user32" (ByVal hwnd As Long, lpdwProcessId As Long) As Long

Private Sub Timer1_Timer()
Dim hwnd As Long ' 储存 FindWindow 函数返回的句柄
hwnd = FindWindow(vbNullString, "YB_OnlineClient") ' 取得进程标识符
If hwnd = 0 Then
Label1.Caption = "未运行"

Else
Label1.Caption = "已运行"
Text1.Text = hwnd
PostMessage hwnd, WM_KEYDOWN, VK_F4, 0& '按下F4键
PostMessage hwnd, WM_UP, VK_F4, 0& '释放F4键
End If
End Sub
我的代码有什么毛病吗怎么后台运行还是不行游戏没反应

算了,发个完整的代码给你吧,自己改.记得常数要定义.
当然,PostMessage的最后一个参数用0也可以,下面是完整的.

窗体代码：
Private Sub Form_Load()
Dim hwnd As Long
hwnd = &HXXXX 'XXXXX表示记事本编辑框的句柄
PostMessage hwnd, WM_KEYDOWN, VK_A, MakeKeyLparam(VK_A, WM_KEYDOWN) '按下A键
PostMessage hwnd, WM_CHAR, Asc("A"), MakeKeyLparam(VK_A, WM_KEYDOWN) '输入字符A
PostMessage hwnd, WM_UP, VK_A, MakeKeyLparam(VK_A, WM_UP) '释放A键
End Sub
模块代码：
Declare Function PostMessage Lib "user32" Alias "PostMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Declare Function MapVirtualKey Lib "user32" Alias "MapVirtualKeyA" (ByVal wCode As Long, ByVal wMapType As Long) As Long

Public Const WM_KEYDOWN = &H100
Public Const WM_KEYUP = &H101
Public Const WM_CHAR = &H102
Public Const VK_A = &H41

Function MakeKeyLparam(ByVal VirtualKey As Long, ByVal flag As Long) As Long
Dim s As String
Dim Firstbyte As String 'lparam参数的24-31位
If flag = WM_KEYDOWN Then '如果是按下键
Firstbyte = "00"
Else
Firstbyte = "C0" '如果是释放键
End If
Dim Scancode As Long
'获得键的扫描码
Scancode = MapVirtualKey(VirtualKey, 0)
Dim Secondbyte As String 'lparam参数的16-23位，即虚拟键扫描码
Secondbyte = Right("00" & Hex(Scancode), 2)
s = Firstbyte & Secondbyte & "0001" '0001为lparam参数的0-15位，即发送次数和其它扩展信息
MakeKeyLparam = Val("&H" & s)
End Function

你的按下f1 postmessage hwnd, wm_keydown, vbkeyf1, 0& '按下f1键 postmessage hwnd, wm_up, vbkeyf1, 0& '释放f1键 按下f2 postmessage hwnd, wm_keydown, vbkeyf2, 0& '按下f2键 postmessage hwnd, wm_up, vbkeyf2, 0& '释放f2键 组合键ctrl + a postmessage hwnd, wm_keydown, vbkeycontrol, 0& '按下ctrl键 postmessage hwnd, wm_keydown, vbkeya, 0& '按下a键 postmessage hwnd, wm_up, vbkeya, 0& '释放a键 postmessage hwnd, wm_up, vbkeycontrol, 0& '释放ctrl键 我写个过程给你 private sub postkey(hwnd as long, keycode as keycodeconstants) postmessage hwnd, wm_keydown, keycode, 0& postmessage hwnd, wm_keyup, keycode, 0& end sub 使用的时候他会出现自动完成的，“vbkey”后面的内容就是你要的按的键

常量声明了吗？timer1.enabeld=true timer1.interval=100有吗？

你说的后台 是 类似qq那种 c+a+z 吧 这东西要hook 用api写的 代码 可以自己搜索 不过一般都有小问题