MSLLHOOKSTRUCT structure (winuser.h)

Contains information about a low-level mouse input event.

Syntax

typedef struct tagMSLLHOOKSTRUCT {
  POINT     pt;
  DWORD     mouseData;
  DWORD     flags;
  DWORD     time;
  ULONG_PTR dwExtraInfo;
} MSLLHOOKSTRUCT, *LPMSLLHOOKSTRUCT, *PMSLLHOOKSTRUCT;

Members

pt

Type: POINT

The x- and y-coordinates of the cursor, in per-monitor-aware screen coordinates.

mouseData

Type: DWORD

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.

Value Meaning
XBUTTON1
0x0001
The first X button was pressed or released.
XBUTTON2
0x0002
The second X button was pressed or released.

flags

Type: DWORD

The event-injected flags. An application can use the following values to test the flags. Testing LLMHF_INJECTED (bit 0) will tell you whether the event was injected. If it was, then testing LLMHF_LOWER_IL_INJECTED (bit 1) will tell you whether or not the event was injected from a process running at lower integrity level.

Value Meaning
LLMHF_INJECTED
0x00000001
Test the event-injected (from any process) flag.
LLMHF_LOWER_IL_INJECTED
0x00000002
Test the event-injected (from a process running at lower integrity level) flag.

time

Type: DWORD

The time stamp for this message.

dwExtraInfo

Type: ULONG_PTR

Additional information associated with the message.

Requirements

Requirement Value
Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Header winuser.h (include Windows.h)

See also

Conceptual

Hooks

LowLevelMouseProc

Other Resources

POINT

Reference

SetWindowsHookEx

WM_MOUSEWHEEL

WM_NCXBUTTONDBLCLK

WM_NCXBUTTONDOWN

WM_NCXBUTTONUP

WM_XBUTTONDBLCLK

WM_XBUTTONDOWN

WM_XBUTTONUP