rainstormmaster的blog
rainstormmaster的blog
        我们知道ClipCursor可以将指针限制到指定区域,那么如何反其道而为之,禁止鼠标进入某个区域呢,答案是用鼠标钩子,在WIN NT 4.0 SP3以上系统可以用WH_MOUSE_LL这个钩子实现,这个钩子的特殊之处是不需要用dll,另外,这个钩子用到了一个结构体,简单说明一下:
typedef struct {
    POINT pt;
    DWORD mouseData;
    DWORD flags;
    DWORD time;
    ULONG_PTR dwExtraInfo;
} MSLLHOOKSTRUCT, *PMSLLHOOKSTRUCT;

Members

pt
Specifies a POINT structure that contains the x- and y-coordinates of the cursor, in screen coordinates.
mouseData
If the message is WM_MOUSEWHEEL, the high-order word of this member is the wheel delta. The low-order word is reserved. A positive value indicates that the wheel was rotated forward, away from the user; a negative value indicates that the wheel was rotated backward, toward the user. One wheel click is defined as WHEEL_DELTA, which is 120.

If the message is WM_XBUTTONDOWN, WM_XBUTTONUP, WM_XBUTTONDBLCLK, WM_NCXBUTTONDOWN, WM_NCXBUTTONUP, or WM_NCXBUTTONDBLCLK, the high-order word specifies which X button was pressed or released, and the low-order word is reserved. This value can be one or more of the following values. Otherwise, mouseData is not used.

XBUTTON1
The first X button was pressed or released.
XBUTTON2
The second X button was pressed or released.
flags
Specifies the event-injected flag. An application can use the following value to test the mouse flags.
Value Purpose
LLMHF_INJECTED Test the event-injected flag.
0
Specifies whether the event was injected. The value is 1 if the event was injected; otherwise, it is 0.
1-15
Reserved.
time
Specifies the time stamp for this message.
dwExtraInfo
Specifies extra information associated with the message.

好了废话少说,看代码:
一个模块,一个窗体(名为Form1)

模块代码:
Option Explicit
Private Declare Sub CopyMemory Lib "kernel32.dll" Alias "RtlMoveMemory" (ByRef Destination As Any, ByRef Source As Any, ByVal Length As Long)
Private Declare Function PtInRect Lib "user32" (lpRect As RECT, ByVal x As Long, ByVal y As Long) As Long
Private Declare Function SetWindowsHookEx Lib "user32" Alias "SetWindowsHookExA" (ByVal idHook As Long, ByVal lpfn As Long, ByVal hmod As Long, ByVal dwThreadId As Long) As Long
Private Declare Function UnhookWindowsHookEx Lib "user32" (ByVal hHook As Long) As Long
Private Declare Function CallNextHookEx Lib "user32" (ByVal hHook As Long, ByVal nCode As Long, ByVal wParam As Long, lparam As Any) As Long
Private Const HC_ACTION = 0
Private Const WH_MOUSE_LL As Long = 14
Private Const WM_MOUSEMOVE = &H200

Public Type RECT
    Left As Long
    Top As Long
    Right As Long
    Bottom As Long
End Type

Private Type POINTAPI
   x As Long
   y As Long
End Type


Private Type MSLLHOOKSTRUCT
    pt As POINTAPI
    mouseData As Long
    Flags As Long
    time As Long
    dwExtraInfo As Long
End Type


Public hHook As Long
Public hRT As RECT
Public Sub EnableHook(hRect As RECT)
    hRT = hRect
    If hHook = 0 Then
       hHook = SetWindowsHookEx(WH_MOUSE_LL, AddressOf HookProc, App.hInstance, 0)
    End If
End Sub
Public Sub FreeHook()
If hHook <> 0 Then
   Call UnhookWindowsHookEx(hHook)
   hHook = 0
End If
End Sub

Public Function HookProc(ByVal nCode As Long, ByVal wParam As Long, ByVal lparam As Long) As Long
    Dim typMHS As MSLLHOOKSTRUCT, pt As POINTAPI
    If nCode < 0 Then
       HookProc = CallNextHookEx(hHook, nCode, wParam, lparam)
       Exit Function
    End If
    If wParam = WM_MOUSEMOVE Then
        Call CopyMemory(typMHS, ByVal lparam, LenB(typMHS))
        pt = typMHS.pt
        If PtInRect(hRT, pt.x, pt.y) <> 0 Then
            HookProc = 1 '取消原本要完成的動作
        Else
            Form1.Caption = "mouse Cursor at " + CStr(pt.x) + "," + CStr(pt.y)
            HookProc = 0 '令待完成的動作繼續完成
        End If
    End If
End Function

窗体代码:
Option Explicit
Const HWND_TOPMOST = -1
Const HWND_NOTOPMOST = -2
Const SWP_NOSIZE = &H1
Const SWP_NOMOVE = &H2
Const SWP_NOACTIVATE = &H10
Const SWP_SHOWWINDOW = &H40
Private Declare Sub SetWindowPos Lib "user32" (ByVal hWnd As Long, ByVal hWndInsertAfter As Long, ByVal x As Long, ByVal y As Long, ByVal cx As Long, ByVal cy As Long, ByVal wFlags As Long)

Private Sub Form_Activate()
   '设置窗口为TOPMOST窗口,目的是便于观察
    SetWindowPos Me.hWnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOACTIVATE Or SWP_SHOWWINDOW Or SWP_NOMOVE Or SWP_NOSIZE
End Sub
Private Sub Form_Load()
    Dim RT As RECT
    With RT
    .Left = 0
    .Right = 400
    .Top = 0
    .Bottom = 300
    End With
    EnableHook RT
End Sub

Private Sub Form_Unload(Cancel As Integer)
    FreeHook
End Sub

需要指出的是VB自带的api浏览器中的PtInRect声明有问题,调用它的时候尽管不报错,但不能判断指定点是否位于RECT内,为此修改了它的声明

另外,我这段程序是禁止鼠标指针进入(0,0)-(400,300)这个区域,在调试的时候可能窗体的关闭按钮正好位于这一区域,这时候,记得按下 alt+F4关闭窗口

posted on 2006-01-18 22:54  学剑学诗两不成  阅读(2963)  评论(0编辑  收藏  举报