原文地址:http://www.zdexe.com/program/201004/604.html
結構8 ：MOUSEHOOKSTRUCT Structure
The MOUSEHOOKSTRUCT structure contains information about a mouse event passed to a WH_MOUSE hook procedure, MouseProc.
MOUSEHOOKSTRUCT結構包含有傳遞給WH_MOUSE鈎子子程MouseProc的，關於鼠標事件的信息。
Syntax語法
typedef struct {
POINT pt;
HWND hwnd;
UINT wHitTestCode;
ULONG_PTR dwExtraInfo;
} MOUSEHOOKSTRUCT, *PMOUSEHOOKSTRUCT;
Members成員
pt ：Specifies a POINT structure that contains the x- and y-coordinates of the cursor, in screen coordinates. 指定在屏幕坐標系下，包含有光標x、y坐標的POINT結構。
hwnd : Handle to the window that will receive the mouse message corresponding to the mouse event. 希望對鼠標事件做出響應、接收鼠標消息的窗體的句柄。
wHitTestCode ：Specifies the hit-test value. For a list of hit-test values, see the description of the WM_NCHITTEST message. 指定點擊測試值。查看WM_NCHITTEST消息可以得到值的列表。
dwExtraInfo ：Specifies extra information associated with the message. 指定和該消息相關聯的附加信息。
結構9：MOUSEHOOKSTRUCTEX Structure
The MOUSEHOOKSTRUCTEX structure contains information about a mouse event passed to a WH_MOUSE hook procedure, MouseProc.
MOUSEHOOKSTRUCTEX結構包含有傳遞給WH_MOUSE鈎子子程MouseProc的關於鼠標事件的信息。
This is an extension of the MOUSEHOOKSTRUCT structure that includes information about wheel movement or the use of the X button.
這是對MOUSEHOOKSTRUCT的擴展。包含有滾輪的活動和X鍵的使用。
Syntax語法
typedef struct {
MOUSEHOOKSTRUCT MOUSEHOOKSTRUCT;
DWORD mouseData;
} MOUSEHOOKSTRUCTEX, *PMOUSEHOOKSTRUCTEX;
Members成員
MOUSEHOOKSTRUCT
The members of a MOUSEHOOKSTRUCT structure make up the first part of this structure.
MOUSEHOOKSTRUCT結構的成員構成了該結構的前面部分。
mouseData
If the message is WM_MOUSEWHEEL, the HIWORD of this member is the wheel delta. The LOWORD is undefined and 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.
如果消息是WM_MOUSEWHEEL，該成員的HIWORD就是wheel delta。LOWORD做為保留未定義。正值表示滾輪向前旋轉，即遠離用戶的方向；負值表示滾輪向后旋轉，即朝向用戶的方向。滾輪的點擊被定義為WHEEL_DELTA,具體值為120。
If the message is WM_XBUTTONDOWN, WM_XBUTTONUP, WM_XBUTTONDBLCLK, WM_NCXBUTTONDOWN, WM_NCXBUTTONUP, or WM_NCXBUTTONDBLCLK, the HIWORD of mouseData specifies which X button was pressed or released, and the LOWORD is undefined and reserved. This member can be one or more of the following values. Otherwise,mouseData is not used.
如果消息是WM_XBUTTONDOWN, WM_XBUTTONUP, WM_XBUTTONDBLCLK, WM_NCXBUTTONDOWN, WM_NCXBUTTONUP, 或者WM_NCXBUTTONDBLCLK, mouseData 的HIWORD值指定哪個X鍵被按下或者釋放，LOWORD做為保留未定義。該成員可以是以下值中的一個或者多個。否則，mouseData未使用。
1．XBUTTON1 ：The first X button was pressed or released. 第一個X鍵被按下或者釋放。
2．XBUTTON2 ：The second X button was pressed or released.第二個X鍵被按下或者釋放。