用SetWindowsHookEX Public 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
Parameters idHook Specifies the type of hook procedure to be installed. This parameter can be one of the following values: Value Description WH_CALLWNDPROC Installs a hook procedure that monitors messages before the system sends them to the destination window procedure. For more information, see the CallWndProc hook procedure. WH_CALLWNDPROCRET Installs a hook procedure that monitors messages after they have been processed by the destination window procedure. For more information, see the CallWndRetProc hook procedure. WH_CBT Installs a hook procedure that receives notifications useful to a computer-based training (CBT) application. For more information, see the CBTProc hook procedure. WH_DEBUG Installs a hook procedure useful for debugging other hook procedures. For more information, see the DebugProc hook procedure. WH_FOREGROUNDIDLE Installs a hook procedure that will be called when the application's foreground thread is about to become idle. This hook is useful for performing low priority tasks during idle time. For more information, see the ForegroundIdleProc hook procedure. WH_GETMESSAGE Installs a hook procedure that monitors messages posted to a message queue. For more information, see the GetMsgProc hook procedure. WH_JOURNALPLAYBACK Installs a hook procedure that posts messages previously recorded by a WH_JOURNALRECORD hook procedure. For more information, see the JournalPlaybackProc hook procedure. WH_JOURNALRECORD Installs a hook procedure that records input messages posted to the system message queue. This hook is useful for recording macros. For more information, see the JournalRecordProc hook procedure. WH_KEYBOARD Installs a hook procedure that monitors keystroke messages. For more information, see the KeyboardProc hook procedure. WH_KEYBOARD_LL Windows NT: Installs a hook procedure that monitors low-level keyboard input events. For more information, see the LowLevelKeyboardProc hook procedure. WH_MOUSE Installs a hook procedure that monitors mouse messages. For more information, see the MouseProc hook procedure. WH_MOUSE_LL Windows NT: Installs a hook procedure that monitors low-level mouse input events. For more information, see the LowLevelMouseProc hook procedure. WH_MSGFILTER Installs a hook procedure that monitors messages generated as a result of an input event in a dialog box, message box, menu, or scroll bar. For more information, see the MessageProc hook procedure. WH_SHELL Installs a hook procedure that receives notifications useful to shell applications. For more information, see the ShellProc hook procedure. WH_SYSMSGFILTER Installs a hook procedure that monitors messages generated as a result of an input event in a dialog box, message box, menu, or scroll bar. The hook procedure monitors these messages for all applications in the system. For more information, see the SysMsgProc hook procedure. lpfn Pointer to the hook procedure. If the dwThreadId parameter is zero or specifies the identifier of a thread created by a different process, the lpfn parameter must point to a hook procedure in a dynamic-link library (DLL). Otherwise, lpfn can point to a hook procedure in the code associated with the current process. hMod Handle to the DLL containing the hook procedure pointed to by the lpfn parameter. The hMod parameter must be set to NULL if the dwThreadId parameter specifies a thread created by the current process and if the hook procedure is within the code associated with the current process. dwThreadId Specifies the identifier of the thread with which the hook procedure is to be associated. If this parameter is zero, the hook procedure is associated with all existing threads. Return Values If the function succeeds, the return value is the handle to the hook procedure. If the function fails, the return value is NULL. To get extended error information, call GetLastError.Res An error may occur if the hMod parameter is NULL and the dwThreadId parameter is zero or specifies the identifier of a thread created by another process. Calling the CallNextHookEx function to chain to the next hook procedure is optional, but it is highly recommended; otherwise, other applications that have installed hooks will not receive hook notifications and may behave incorrectly as a result. You should call CallNextHookEx unless you absolutely need to prevent the notification from being seen by other applications. Before terminating, an application must call the UnhookWindowsHookEx function to free system resources associated with the hook. The scope of a hook depends on the hook type. Some hooks can be set only with system scope; others can also be set for only a specific thread, as shown in the following list: Hook Scope WH_CALLWNDPROC Thread or system WH_CALLWNDPROCRET Thread or system WH_CBT Thread or system WH_DEBUG Thread or system WH_FOREGROUNDIDLE Thread or system WH_GETMESSAGE Thread or system WH_JOURNALPLAYBACK System only WH_JOURNALRECORD System only WH_KEYBOARD Thread or system WH_KEYBOARD_LL Thread or system WH_MOUSE Thread or system WH_MOUSE_LL Thread or system WH_MSGFILTER Thread or system WH_SHELL Thread or system WH_SYSMSGFILTER System only For a specified hook type, thread hooks are called first, then system hooks. The system hooks are a shared resource, and installing one affects all applications. All system hook functions must be in libraries. System hooks should be restricted to special-purpose applications or to use as a development aid during application debugging. Libraries that no longer need a hook should remove the hook procedure.
你可能会用到WH_KEYBOARD，它的回调函数说明如下（你需要用vb改写）： LRESULT CALLBACK KeyboardProc( int code, // hook code WPARAM wParam, // virtual-key code LPARAM lParam // keystroke-message information );
Parameters code Specifies a code the hook procedure uses to determine how to process the message. This parameter can be one of the following values: Value Meaning HC_ACTION The wParam and lParam parameters contain information about a keystroke message. HC_NOREMOVE The wParam and lParam parameters contain information about a keystroke message, and the keystroke message has not been removed from the message queue. (An application called the PeekMessage function, specifying the PM_NOREMOVE flag.) If code is less than zero, the hook procedure must pass the message to the CallNextHookEx function without further processing and should return the value returned by CallNextHookEx. wParam Specifies the virtual-key code of the key that generated the keystroke message. lParam Specifies the repeat count, scan code, extended-key flag, context code, previous key-state flag, and transition-state flag. This parameter can be a combination of the following values: Value Description 0–15 Specifies the repeat count. The value is the number of times the keystroke is repeated as a result of the user's holding down the key. 16–23 Specifies the scan code. The value depends on the original equipment manufacturer (OEM). 24 Specifies whether the key is an extended key, such as a function key or a key on the numeric keypad. The value is 1 if the key is an extended key; otherwise, it is 0. 25–28 Reserved. 29 Specifies the context code. The value is 1 if the alt key is down; otherwise, it is 0. 30 Specifies the previous key state. The value is 1 if the key is down before the message is sent; it is 0 if the key is up. 31 Specifies the transition state. The value is 0 if the key is being pressed and 1 if it is being released.
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Public 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
idHook
Specifies the type of hook procedure to be installed. This parameter can be one of the following values: Value Description
WH_CALLWNDPROC Installs a hook procedure that monitors messages before the system sends them to the destination window procedure. For more information, see the CallWndProc hook procedure.
WH_CALLWNDPROCRET Installs a hook procedure that monitors messages after they have been processed by the destination window procedure. For more information, see the CallWndRetProc hook procedure.
WH_CBT Installs a hook procedure that receives notifications useful to a computer-based training (CBT) application. For more information, see the CBTProc hook procedure.
WH_DEBUG Installs a hook procedure useful for debugging other hook procedures. For more information, see the DebugProc hook procedure.
WH_FOREGROUNDIDLE Installs a hook procedure that will be called when the application's foreground thread is about to become idle. This hook is useful for performing low priority tasks during idle time. For more information, see the ForegroundIdleProc hook procedure.
WH_GETMESSAGE Installs a hook procedure that monitors messages posted to a message queue. For more information, see the GetMsgProc hook procedure.
WH_JOURNALPLAYBACK Installs a hook procedure that posts messages previously recorded by a WH_JOURNALRECORD hook procedure. For more information, see the JournalPlaybackProc hook procedure.
WH_JOURNALRECORD Installs a hook procedure that records input messages posted to the system message queue. This hook is useful for recording macros. For more information, see the JournalRecordProc hook procedure.
WH_KEYBOARD Installs a hook procedure that monitors keystroke messages. For more information, see the KeyboardProc hook procedure.
WH_KEYBOARD_LL Windows NT: Installs a hook procedure that monitors low-level keyboard input events. For more information, see the LowLevelKeyboardProc hook procedure.
WH_MOUSE Installs a hook procedure that monitors mouse messages. For more information, see the MouseProc hook procedure.
WH_MOUSE_LL Windows NT: Installs a hook procedure that monitors low-level mouse input events. For more information, see the LowLevelMouseProc hook procedure.
WH_MSGFILTER Installs a hook procedure that monitors messages generated as a result of an input event in a dialog box, message box, menu, or scroll bar. For more information, see the MessageProc hook procedure.
WH_SHELL Installs a hook procedure that receives notifications useful to shell applications. For more information, see the ShellProc hook procedure.
WH_SYSMSGFILTER Installs a hook procedure that monitors messages generated as a result of an input event in a dialog box, message box, menu, or scroll bar. The hook procedure monitors these messages for all applications in the system. For more information, see the SysMsgProc hook procedure.
lpfn
Pointer to the hook procedure. If the dwThreadId parameter is zero or specifies the identifier of a thread created by a different process, the lpfn parameter must point to a hook procedure in a dynamic-link library (DLL). Otherwise, lpfn can point to a hook procedure in the code associated with the current process.
hMod
Handle to the DLL containing the hook procedure pointed to by the lpfn parameter. The hMod parameter must be set to NULL if the dwThreadId parameter specifies a thread created by the current process and if the hook procedure is within the code associated with the current process.
dwThreadId
Specifies the identifier of the thread with which the hook procedure is to be associated. If this parameter is zero, the hook procedure is associated with all existing threads.
Return Values
If the function succeeds, the return value is the handle to the hook procedure. If the function fails, the return value is NULL. To get extended error information, call GetLastError.Res
An error may occur if the hMod parameter is NULL and the dwThreadId parameter is zero or specifies the identifier of a thread created by another process. Calling the CallNextHookEx function to chain to the next hook procedure is optional, but it is highly recommended; otherwise, other applications that have installed hooks will not receive hook notifications and may behave incorrectly as a result. You should call CallNextHookEx unless you absolutely need to prevent the notification from being seen by other applications. Before terminating, an application must call the UnhookWindowsHookEx function to free system resources associated with the hook. The scope of a hook depends on the hook type. Some hooks can be set only with system scope; others can also be set for only a specific thread, as shown in the following list: Hook Scope
WH_CALLWNDPROC Thread or system
WH_CALLWNDPROCRET Thread or system
WH_CBT Thread or system
WH_DEBUG Thread or system
WH_FOREGROUNDIDLE Thread or system
WH_GETMESSAGE Thread or system
WH_JOURNALPLAYBACK System only
WH_JOURNALRECORD System only
WH_KEYBOARD Thread or system
WH_KEYBOARD_LL Thread or system
WH_MOUSE Thread or system
WH_MOUSE_LL Thread or system
WH_MSGFILTER Thread or system
WH_SHELL Thread or system
WH_SYSMSGFILTER System only
For a specified hook type, thread hooks are called first, then system hooks. The system hooks are a shared resource, and installing one affects all applications. All system hook functions must be in libraries. System hooks should be restricted to special-purpose applications or to use as a development aid during application debugging. Libraries that no longer need a hook should remove the hook procedure.
LRESULT CALLBACK KeyboardProc(
int code, // hook code
WPARAM wParam, // virtual-key code
LPARAM lParam // keystroke-message information
);
Parameters
code
Specifies a code the hook procedure uses to determine how to process the message. This parameter can be one of the following values: Value Meaning
HC_ACTION The wParam and lParam parameters contain information about a keystroke message.
HC_NOREMOVE The wParam and lParam parameters contain information about a keystroke message, and the keystroke message has not been removed from the message queue. (An application called the PeekMessage function, specifying the PM_NOREMOVE flag.)
If code is less than zero, the hook procedure must pass the message to the CallNextHookEx function without further processing and should return the value returned by CallNextHookEx. wParam
Specifies the virtual-key code of the key that generated the keystroke message.
lParam
Specifies the repeat count, scan code, extended-key flag, context code, previous key-state flag, and transition-state flag. This parameter can be a combination of the following values: Value Description
0–15 Specifies the repeat count. The value is the number of times the keystroke is repeated as a result of the user's holding down the key.
16–23 Specifies the scan code. The value depends on the original equipment manufacturer (OEM).
24 Specifies whether the key is an extended key, such as a function key or a key on the numeric keypad. The value is 1 if the key is an extended key; otherwise, it is 0.
25–28 Reserved.
29 Specifies the context code. The value is 1 if the alt key is down; otherwise, it is 0.
30 Specifies the previous key state. The value is 1 if the key is down before the message is sent; it is 0 if the key is up.
31 Specifies the transition state. The value is 0 if the key is being pressed and 1 if it is being released.