Windows messages are used to communicate between the operating system and applications, and also between different parts of an application.
A Windows message is simply a numeric code that designates a particular event. For example, if the user presses the left mouse button, the window receives a message that has the following message code: WM_LBUTTONDOWN (0x0201).
Some messages have data associated with them. For example, the WM_LBUTTONDOWN message includes the X and Y coordinates of the mouse cursor.
The following are the ranges of message numbers:
For details, see About Messages and Message Queues (Microsoft Docs).
In AutoHotkey, the message numbers can be used for the MsgNumber parameter of PostMessage, SendMessage, and OnMessage. Below is a list of some values. 特定のメッセージ（例：WM_VSCROLL）の使い方を詳しく知りたい場合は、Microsoft Docsや、お好みの検索エンジンで調べてください。また、メッセージ・チュートリアルもご覧ください。
WM_NULL := 0x0000 WM_CREATE := 0x0001 WM_DESTROY := 0x0002 WM_MOVE := 0x0003 WM_SIZE := 0x0005 WM_ACTIVATE := 0x0006 WM_SETFOCUS := 0x0007 WM_KILLFOCUS := 0x0008 WM_ENABLE := 0x000A WM_SETREDRAW := 0x000B WM_SETTEXT := 0x000C WM_GETTEXT := 0x000D WM_GETTEXTLENGTH := 0x000E WM_PAINT := 0x000F WM_CLOSE := 0x0010 WM_QUERYENDSESSION := 0x0011 WM_QUIT := 0x0012 WM_QUERYOPEN := 0x0013 WM_ERASEBKGND := 0x0014 WM_SYSCOLORCHANGE := 0x0015 WM_ENDSESSION := 0x0016 WM_SYSTEMERROR := 0x0017 WM_SHOWWINDOW := 0x0018 WM_CTLCOLOR := 0x0019 WM_WININICHANGE := 0x001A WM_SETTINGCHANGE := 0x001A WM_DEVMODECHANGE := 0x001B WM_ACTIVATEAPP := 0x001C WM_FONTCHANGE := 0x001D WM_TIMECHANGE := 0x001E WM_CANCELMODE := 0x001F WM_SETCURSOR := 0x0020 WM_MOUSEACTIVATE := 0x0021 WM_CHILDACTIVATE := 0x0022 WM_QUEUESYNC := 0x0023 WM_GETMINMAXINFO := 0x0024 WM_PAINTICON := 0x0026 WM_ICONERASEBKGND := 0x0027 WM_NEXTDLGCTL := 0x0028 WM_SPOOLERSTATUS := 0x002A WM_DRAWITEM := 0x002B WM_MEASUREITEM := 0x002C WM_DELETEITEM := 0x002D WM_VKEYTOITEM := 0x002E WM_CHARTOITEM := 0x002F WM_SETFONT := 0x0030 WM_GETFONT := 0x0031 WM_SETHOTKEY := 0x0032 WM_GETHOTKEY := 0x0033 WM_QUERYDRAGICON := 0x0037 WM_COMPAREITEM := 0x0039 WM_COMPACTING := 0x0041 WM_WINDOWPOSCHANGING := 0x0046 WM_WINDOWPOSCHANGED := 0x0047 WM_POWER := 0x0048 WM_COPYDATA := 0x004A WM_CANCELJOURNAL := 0x004B WM_NOTIFY := 0x004E WM_INPUTLANGCHANGEREQUEST := 0x0050 WM_INPUTLANGCHANGE := 0x0051 WM_TCARD := 0x0052 WM_HELP := 0x0053 WM_USERCHANGED := 0x0054 WM_NOTIFYFORMAT := 0x0055 WM_CONTEXTMENU := 0x007B WM_STYLECHANGING := 0x007C WM_STYLECHANGED := 0x007D WM_DISPLAYCHANGE := 0x007E WM_GETICON := 0x007F WM_SETICON := 0x0080 WM_NCCREATE := 0x0081 WM_NCDESTROY := 0x0082 WM_NCCALCSIZE := 0x0083 WM_NCHITTEST := 0x0084 WM_NCPAINT := 0x0085 WM_NCACTIVATE := 0x0086 WM_GETDLGCODE := 0x0087 WM_NCMOUSEMOVE := 0x00A0 WM_NCLBUTTONDOWN := 0x00A1 WM_NCLBUTTONUP := 0x00A2 WM_NCLBUTTONDBLCLK := 0x00A3 WM_NCRBUTTONDOWN := 0x00A4 WM_NCRBUTTONUP := 0x00A5 WM_NCRBUTTONDBLCLK := 0x00A6 WM_NCMBUTTONDOWN := 0x00A7 WM_NCMBUTTONUP := 0x00A8 WM_NCMBUTTONDBLCLK := 0x00A9 WM_KEYFIRST := 0x0100 WM_KEYDOWN := 0x0100 WM_KEYUP := 0x0101 WM_CHAR := 0x0102 WM_DEADCHAR := 0x0103 WM_SYSKEYDOWN := 0x0104 WM_SYSKEYUP := 0x0105 WM_SYSCHAR := 0x0106 WM_SYSDEADCHAR := 0x0107 WM_KEYLAST := 0x0108 WM_IME_STARTCOMPOSITION := 0x010D WM_IME_ENDCOMPOSITION := 0x010E WM_IME_COMPOSITION := 0x010F WM_IME_KEYLAST := 0x010F WM_INITDIALOG := 0x0110 WM_COMMAND := 0x0111 WM_SYSCOMMAND := 0x0112 WM_TIMER := 0x0113 WM_HSCROLL := 0x0114 WM_VSCROLL := 0x0115 WM_INITMENU := 0x0116 WM_INITMENUPOPUP := 0x0117 WM_MENUSELECT := 0x011F WM_MENUCHAR := 0x0120 WM_ENTERIDLE := 0x0121 WM_CTLCOLORMSGBOX := 0x0132 WM_CTLCOLOREDIT := 0x0133 WM_CTLCOLORLISTBOX := 0x0134 WM_CTLCOLORBTN := 0x0135 WM_CTLCOLORDLG := 0x0136 WM_CTLCOLORSCROLLBAR := 0x0137 WM_CTLCOLORSTATIC := 0x0138 WM_MOUSEFIRST := 0x0200 WM_MOUSEMOVE := 0x0200 WM_LBUTTONDOWN := 0x0201 WM_LBUTTONUP := 0x0202 WM_LBUTTONDBLCLK := 0x0203 WM_RBUTTONDOWN := 0x0204 WM_RBUTTONUP := 0x0205 WM_RBUTTONDBLCLK := 0x0206 WM_MBUTTONDOWN := 0x0207 WM_MBUTTONUP := 0x0208 WM_MBUTTONDBLCLK := 0x0209 WM_MOUSEWHEEL := 0x020A WM_MOUSEHWHEEL := 0x020E WM_PARENTNOTIFY := 0x0210 WM_ENTERMENULOOP := 0x0211 WM_EXITMENULOOP := 0x0212 WM_NEXTMENU := 0x0213 WM_SIZING := 0x0214 WM_CAPTURECHANGED := 0x0215 WM_MOVING := 0x0216 WM_POWERBROADCAST := 0x0218 WM_DEVICECHANGE := 0x0219 WM_MDICREATE := 0x0220 WM_MDIDESTROY := 0x0221 WM_MDIACTIVATE := 0x0222 WM_MDIRESTORE := 0x0223 WM_MDINEXT := 0x0224 WM_MDIMAXIMIZE := 0x0225 WM_MDITILE := 0x0226 WM_MDICASCADE := 0x0227 WM_MDIICONARRANGE := 0x0228 WM_MDIGETACTIVE := 0x0229 WM_MDISETMENU := 0x0230 WM_ENTERSIZEMOVE := 0x0231 WM_EXITSIZEMOVE := 0x0232 WM_DROPFILES := 0x0233 WM_MDIREFRESHMENU := 0x0234 WM_IME_SETCONTEXT := 0x0281 WM_IME_NOTIFY := 0x0282 WM_IME_CONTROL := 0x0283 WM_IME_COMPOSITIONFULL := 0x0284 WM_IME_SELECT := 0x0285 WM_IME_CHAR := 0x0286 WM_IME_KEYDOWN := 0x0290 WM_IME_KEYUP := 0x0291 WM_MOUSEHOVER := 0x02A1 WM_NCMOUSELEAVE := 0x02A2 WM_MOUSELEAVE := 0x02A3 WM_CUT := 0x0300 WM_COPY := 0x0301 WM_PASTE := 0x0302 WM_CLEAR := 0x0303 WM_UNDO := 0x0304 WM_RENDERFORMAT := 0x0305 WM_RENDERALLFORMATS := 0x0306 WM_DESTROYCLIPBOARD := 0x0307 WM_DRAWCLIPBOARD := 0x0308 WM_PAINTCLIPBOARD := 0x0309 WM_VSCROLLCLIPBOARD := 0x030A WM_SIZECLIPBOARD := 0x030B WM_ASKCBFORMATNAME := 0x030C WM_CHANGECBCHAIN := 0x030D WM_HSCROLLCLIPBOARD := 0x030E WM_QUERYNEWPALETTE := 0x030F WM_PALETTEISCHANGING := 0x0310 WM_PALETTECHANGED := 0x0311 WM_HOTKEY := 0x0312 WM_PRINT := 0x0317 WM_PRINTCLIENT := 0x0318 WM_HANDHELDFIRST := 0x0358 WM_HANDHELDLAST := 0x035F WM_PENWINFIRST := 0x0380 WM_PENWINLAST := 0x038F WM_COALESCE_FIRST := 0x0390 WM_COALESCE_LAST := 0x039F WM_DDE_FIRST := 0x03E0 WM_DDE_INITIATE := 0x03E0 WM_DDE_TERMINATE := 0x03E1 WM_DDE_ADVISE := 0x03E2 WM_DDE_UNADVISE := 0x03E3 WM_DDE_ACK := 0x03E4 WM_DDE_DATA := 0x03E5 WM_DDE_REQUEST := 0x03E6 WM_DDE_POKE := 0x03E7 WM_DDE_EXECUTE := 0x03E8 WM_DDE_LAST := 0x03E8 WM_USER := 0x0400 WM_APP := 0x8000