Windows and Messages
Overview of the Windows and Messages technology.
The Windows and Messages technology is not associated with any headers.
For programming guidance for this technology, see:
Functions
| AdjustWindowRect Calculates the required size of the window rectangle, based on the desired client-rectangle size. The window rectangle can then be passed to the CreateWindow function to create a window whose client area is the desired size. |
| AdjustWindowRectEx Calculates the required size of the window rectangle, based on the desired size of the client rectangle. The window rectangle can then be passed to the CreateWindowEx function to create a window whose client area is the desired size. |
| AllowSetForegroundWindow Enables the specified process to set the foreground window using the SetForegroundWindow function. The calling process must already be able to set the foreground window. For more information, see Remarks later in this topic. |
| AnimateWindow Enables you to produce special effects when showing or hiding windows. There are four types of animation:_roll, slide, collapse or expand, and alpha-blended fade. |
| AnyPopup Indicates whether an owned, visible, top-level pop-up, or overlapped window exists on the screen. The function searches the entire screen, not just the calling application's client area. |
| ArrangeIconicWindows Arranges all the minimized (iconic) child windows of the specified parent window. |
| BeginDeferWindowPos Allocates memory for a multiple-window- position structure and returns the handle to the structure. |
| BringWindowToTop Brings the specified window to the top of the Z order. If the window is a top-level window, it is activated. If the window is a child window, the top-level parent window associated with the child window is activated. |
| BroadcastSystemMessage The BroadcastSystemMessage function sends a message to the specified recipients. (BroadcastSystemMessage) |
| BroadcastSystemMessageA Sends a message to the specified recipients. (BroadcastSystemMessageA) |
| BroadcastSystemMessageExA Sends a message to the specified recipients. (BroadcastSystemMessageExA) |
| BroadcastSystemMessageExW Sends a message to the specified recipients. (BroadcastSystemMessageExW) |
| BroadcastSystemMessageW The BroadcastSystemMessageW (Unicode) function sends a message to the specified recipients. (BroadcastSystemMessageW) |
| CalculatePopupWindowPosition Calculates an appropriate pop-up window position using the specified anchor point, pop-up window size, flags, and the optional exclude rectangle. |
| CallMsgFilterA Passes the specified message and hook code to the hook procedures associated with the WH_SYSMSGFILTER and WH_MSGFILTER hooks. (ANSI) |
| CallMsgFilterW Passes the specified message and hook code to the hook procedures associated with the WH_SYSMSGFILTER and WH_MSGFILTER hooks. (Unicode) |
| CallNextHookEx Passes the hook information to the next hook procedure in the current hook chain. A hook procedure can call this function either before or after processing the hook information. |
| CallWindowProcA Passes message information to the specified window procedure. (ANSI) |
| CallWindowProcW Passes message information to the specified window procedure. (Unicode) |
| CascadeWindows Cascades the specified child windows of the specified parent window. |
| ChangeWindowMessageFilter Adds or removes a message from the User Interface Privilege Isolation (UIPI) message filter. |
| ChangeWindowMessageFilterEx Modifies the User Interface Privilege Isolation (UIPI) message filter for a specified window. |
| ChildWindowFromPoint Determines which, if any, of the child windows belonging to a parent window contains the specified point. The search is restricted to immediate child windows. Grandchildren, and deeper descendant windows are not searched. |
| ChildWindowFromPointEx Determines which, if any, of the child windows belonging to the specified parent window contains the specified point. |
| CloseWindow Minimizes (but does not destroy) the specified window. |
| CreateMDIWindowA Creates a multiple-document interface (MDI) child window. (ANSI) |
| CreateMDIWindowW Creates a multiple-document interface (MDI) child window. (Unicode) |
| CreateWindowA Creates an overlapped, pop-up, or child window. (ANSI) |
| CreateWindowExA Creates an overlapped, pop-up, or child window with an extended window style; otherwise, this function is identical to the CreateWindow function. (ANSI) |
| CreateWindowExW Creates an overlapped, pop-up, or child window with an extended window style; otherwise, this function is identical to the CreateWindow function. (Unicode) |
| CreateWindowW Creates an overlapped, pop-up, or child window. (Unicode) |
| DeferWindowPos Updates the specified multiple-window � position structure for the specified window. |
| DefFrameProcA Provides default processing for any window messages that the window procedure of a multiple-document interface (MDI) frame window does not process. (ANSI) |
| DefFrameProcW Provides default processing for any window messages that the window procedure of a multiple-document interface (MDI) frame window does not process. (Unicode) |
| DefMDIChildProcA Provides default processing for any window message that the window procedure of a multiple-document interface (MDI) child window does not process. (ANSI) |
| DefMDIChildProcW Provides default processing for any window message that the window procedure of a multiple-document interface (MDI) child window does not process. (Unicode) |
| DefWindowProcA Calls the default window procedure to provide default processing for any window messages that an application does not process. (ANSI) |
| DefWindowProcW Calls the default window procedure to provide default processing for any window messages that an application does not process. (Unicode) |
| DeregisterShellHookWindow Unregisters a specified Shell window that is registered to receive Shell hook messages. |
| DestroyWindow Destroys the specified window. |
| DispatchMessage The DispatchMessage function dispatches a message to a window procedure. It is typically used to dispatch a message retrieved by the GetMessage function. |
| DispatchMessageA Dispatches a message to a window procedure. It is typically used to dispatch a message retrieved by the GetMessage function. (DispatchMessageA) |
| DispatchMessageW The DispatchMessageW (Unicode) function dispatches a message to a window procedure. It is typically used to dispatch a message retrieved by the GetMessage function. |
| EndDeferWindowPos Simultaneously updates the position and size of one or more windows in a single screen-refreshing cycle. |
| EndTask Forcibly closes the specified window. |
| EnumChildWindows Enumerates the child windows that belong to the specified parent window by passing the handle to each child window, in turn, to an application-defined callback function. |
| EnumPropsA Enumerates all entries in the property list of a window by passing them, one by one, to the specified callback function. EnumProps continues until the last entry is enumerated or the callback function returns FALSE. (ANSI) |
| EnumPropsExA Enumerates all entries in the property list of a window by passing them, one by one, to the specified callback function. EnumPropsEx continues until the last entry is enumerated or the callback function returns FALSE. (ANSI) |
| EnumPropsExW Enumerates all entries in the property list of a window by passing them, one by one, to the specified callback function. EnumPropsEx continues until the last entry is enumerated or the callback function returns FALSE. (Unicode) |
| EnumPropsW Enumerates all entries in the property list of a window by passing them, one by one, to the specified callback function. EnumProps continues until the last entry is enumerated or the callback function returns FALSE. (Unicode) |
| EnumThreadWindows Enumerates all nonchild windows associated with a thread by passing the handle to each window, in turn, to an application-defined callback function. |
| EnumWindows Enumerates all top-level windows on the screen by passing the handle to each window, in turn, to an application-defined callback function. EnumWindows continues until the last top-level window is enumerated or the callback function returns FALSE. |
| FindWindowA Retrieves a handle to the top-level window whose class name and window name match the specified strings. This function does not search child windows. This function does not perform a case-sensitive search. (ANSI) |
| FindWindowExA Retrieves a handle to a window whose class name and window name match the specified strings. The function searches child windows, beginning with the one following the specified child window. This function does not perform a case-sensitive search. (ANSI) |
| FindWindowExW Retrieves a handle to a window whose class name and window name match the specified strings. The function searches child windows, beginning with the one following the specified child window. This function does not perform a case-sensitive search. (Unicode) |
| FindWindowW Retrieves a handle to the top-level window whose class name and window name match the specified strings. This function does not search child windows. This function does not perform a case-sensitive search. (Unicode) |
| GET_X_LPARAM Retrieves the signed x-coordinate from the specified LPARAM value. |
| GET_Y_LPARAM Retrieves the signed y-coordinate from the given LPARAM value. |
| GetAltTabInfoA Retrieves status information for the specified window if it is the application-switching (ALT+TAB) window. (ANSI) |
| GetAltTabInfoW Retrieves status information for the specified window if it is the application-switching (ALT+TAB) window. (Unicode) |
| GetAncestor Retrieves the handle to the ancestor of the specified window. |
| GetClassInfoA Retrieves information about a window class. (ANSI) |
| GetClassInfoExA Retrieves information about a window class, including a handle to the small icon associated with the window class. The GetClassInfo function does not retrieve a handle to the small icon. (ANSI) |
| GetClassInfoExW Retrieves information about a window class, including a handle to the small icon associated with the window class. The GetClassInfo function does not retrieve a handle to the small icon. (Unicode) |
| GetClassInfoW Retrieves information about a window class. (Unicode) |
| GetClassLongA Retrieves the specified 32-bit (DWORD) value from the WNDCLASSEX structure associated with the specified window. (ANSI) |
| GetClassLongPtrA Retrieves the specified value from the WNDCLASSEX structure associated with the specified window. (ANSI) |
| GetClassLongPtrW Retrieves the specified value from the WNDCLASSEX structure associated with the specified window. (Unicode) |
| GetClassLongW Retrieves the specified 32-bit (DWORD) value from the WNDCLASSEX structure associated with the specified window. (Unicode) |
| GetClassName The GetClassName function retrieves the name of the class to which the specified window belongs. (GetClassName) |
| GetClassNameA Retrieves the name of the class to which the specified window belongs. (GetClassNameA) |
| GetClassNameW The GetClassNameW (Unicode) function retrieves the name of the class to which the specified window belongs. (GetClassNameW) |
| GetClassWord Retrieves the 16-bit (WORD) value at the specified offset into the extra class memory for the window class to which the specified window belongs. |
| GetClientRect Retrieves the coordinates of a window's client area. |
| GetDesktopWindow Retrieves a handle to the desktop window. The desktop window covers the entire screen. The desktop window is the area on top of which other windows are painted. |
| GetForegroundWindow Retrieves a handle to the foreground window (the window with which the user is currently working). The system assigns a slightly higher priority to the thread that creates the foreground window than it does to other threads. |
| GetGUIThreadInfo Retrieves information about the active window or a specified GUI thread. |
| GetInputState Determines whether there are mouse-button or keyboard messages in the calling thread's message queue. |
| GetLastActivePopup Determines which pop-up window owned by the specified window was most recently active. |
| GetLayeredWindowAttributes Retrieves the opacity and transparency color key of a layered window. |
| GetMessage The GetMessage function retrieves a message from the calling thread's message queue. (GetMessage) |
| GetMessageA Retrieves a message from the calling thread's message queue. The function dispatches incoming sent messages until a posted message is available for retrieval. (GetMessageA) |
| GetMessageExtraInfo Retrieves the extra message information for the current thread. Extra message information is an application- or driver-defined value associated with the current thread's message queue. |
| GetMessagePos Retrieves the cursor position for the last message retrieved by the GetMessage function. |
| GetMessageTime Retrieves the message time for the last message retrieved by the GetMessage function. |
| GetMessageW The GetMessageW function (Unicode) retrieves a message from the calling thread's message queue. (GetMessageW) |
| GetNextWindow Retrieves a handle to the next or previous window in the Z-Order. The next window is below the specified window; the previous window is above. |
| GetParent Retrieves a handle to the specified window's parent or owner. |
| GetProcessDefaultLayout Retrieves the default layout that is used when windows are created with no parent or owner. |
| GetPropA Retrieves a data handle from the property list of the specified window. The character string identifies the handle to be retrieved. The string and handle must have been added to the property list by a previous call to the SetProp function. (ANSI) |
| GetPropW Retrieves a data handle from the property list of the specified window. The character string identifies the handle to be retrieved. The string and handle must have been added to the property list by a previous call to the SetProp function. (Unicode) |
| GetQueueStatus Retrieves the type of messages found in the calling thread's message queue. |
| GetShellWindow Retrieves a handle to the Shell's desktop window. |
| GetSysColor Retrieves the current color of the specified display element. |
| GetSystemMetrics Retrieves the specified system metric or system configuration setting. |
| GetTitleBarInfo Retrieves information about the specified title bar. |
| GetTopWindow Examines the Z order of the child windows associated with the specified parent window and retrieves a handle to the child window at the top of the Z order. |
| GetWindow Retrieves a handle to a window that has the specified relationship (Z-Order or owner) to the specified window. |
| GetWindowDisplayAffinity Retrieves the current display affinity setting, from any process, for a given window. |
| GetWindowInfo Retrieves information about the specified window. (GetWindowInfo) |
| GetWindowLongA Retrieves information about the specified window. (GetWindowLongA) |
| GetWindowLongPtrA Retrieves information about the specified window. The function also retrieves the value at a specified offset into the extra window memory. (ANSI) |
| GetWindowLongPtrW Retrieves information about the specified window. The function also retrieves the value at a specified offset into the extra window memory. (Unicode) |
| GetWindowLongW Retrieves information about the specified window. (GetWindowLongW) |
| GetWindowModuleFileNameA Retrieves the full path and file name of the module associated with the specified window handle. (ANSI) |
| GetWindowModuleFileNameW Retrieves the full path and file name of the module associated with the specified window handle. (Unicode) |
| GetWindowPlacement Retrieves the show state and the restored, minimized, and maximized positions of the specified window. |
| GetWindowRect Retrieves the dimensions of the bounding rectangle of the specified window. The dimensions are given in screen coordinates that are relative to the upper-left corner of the screen. |
| GetWindowTextA Copies the text of the specified window's title bar (if it has one) into a buffer. If the specified window is a control, the text of the control is copied. However, GetWindowText cannot retrieve the text of a control in another application. (ANSI) |
| GetWindowTextLengthA Retrieves the length, in characters, of the specified window's title bar text (if the window has a title bar). (ANSI) |
| GetWindowTextLengthW Retrieves the length, in characters, of the specified window's title bar text (if the window has a title bar). (Unicode) |
| GetWindowTextW Copies the text of the specified window's title bar (if it has one) into a buffer. If the specified window is a control, the text of the control is copied. However, GetWindowText cannot retrieve the text of a control in another application. (Unicode) |
| GetWindowThreadProcessId Retrieves the identifier of the thread that created the specified window and, optionally, the identifier of the process that created the window. |
| GetWindowWord Retrieves the 16-bit (DWORD) value at the specified offset into the extra window memor |
| HOOKPROC An application-defined or library-defined callback function used with the SetWindowsHookEx function. The system calls this function after the SendMessage function is called. The hook procedure can examine the message; it cannot modify it. |
| InSendMessage Determines whether the current window procedure is processing a message that was sent from another thread (in the same process or a different process) by a call to the SendMessage function. |
| InSendMessageEx Determines whether the current window procedure is processing a message that was sent from another thread (in the same process or a different process). |
| InternalGetWindowText Copies the text of the specified window's title bar (if it has one) into a buffer. |
| IsChild Determines whether a window is a child window or descendant window of a specified parent window. |
| IsGUIThread Determines whether the calling thread is already a GUI thread. It can also optionally convert the thread to a GUI thread. |
| IsHungAppWindow Determines whether the system considers that a specified application is not responding. |
| IsIconic Determines whether the specified window is minimized (iconic). |
| IsProcessDPIAware IsProcessDPIAware may be altered or unavailable. Instead, use GetProcessDPIAwareness. |
| IsWindow Determines whether the specified window handle identifies an existing window. |
| IsWindowArranged Determines whether the specified window is arranged (that is, whether it's snapped). |
| IsWindowUnicode Determines whether the specified window is a native Unicode window. |
| IsWindowVisible Determines the visibility state of the specified window. |
| IsZoomed Determines whether a window is maximized. |
| KillTimer Destroys the specified timer. |
| LockSetForegroundWindow The foreground process can call the LockSetForegroundWindow function to disable calls to the SetForegroundWindow function. |
| LogicalToPhysicalPoint Converts the logical coordinates of a point in a window to physical coordinates. |
| MAKELPARAM Creates a value for use as an lParam parameter in a message. The macro concatenates the specified values. |
| MAKELRESULT Creates a value for use as a return value from a window procedure. The macro concatenates the specified values. |
| MAKEWPARAM Creates a value for use as a wParam parameter in a message. The macro concatenates the specified values. |
| MoveWindow Changes the position and dimensions of the specified window. |
| OpenIcon Restores a minimized (iconic) window to its previous size and position; it then activates the window. |
| PeekMessageA Dispatches incoming nonqueued messages, checks the thread message queue for a posted message, and retrieves the message (if any exist). (ANSI) |
| PeekMessageW Dispatches incoming nonqueued messages, checks the thread message queue for a posted message, and retrieves the message (if any exist). (Unicode) |
| PhysicalToLogicalPoint Converts the physical coordinates of a point in a window to logical coordinates. |
| PostMessageA Places (posts) a message in the message queue associated with the thread that created the specified window and returns without waiting for the thread to process the message. (ANSI) |
| PostMessageW Places (posts) a message in the message queue associated with the thread that created the specified window and returns without waiting for the thread to process the message. (Unicode) |
| PostQuitMessage Indicates to the system that a thread has made a request to terminate (quit). It is typically used in response to a WM_DESTROY message. |
| PostThreadMessageA Posts a message to the message queue of the specified thread. It returns without waiting for the thread to process the message. (ANSI) |
| PostThreadMessageW Posts a message to the message queue of the specified thread. It returns without waiting for the thread to process the message. (Unicode) |
| PROPENUMPROCA An application-defined callback function used with the EnumProps function. (ANSI) |
| PROPENUMPROCEXA Application-defined callback function used with the EnumPropsEx function. (ANSI) |
| PROPENUMPROCEXW Application-defined callback function used with the EnumPropsEx function. (Unicode) |
| PROPENUMPROCW An application-defined callback function used with the EnumProps function. (Unicode) |
| RealChildWindowFromPoint Retrieves a handle to the child window at the specified point. The search is restricted to immediate child windows; grandchildren and deeper descendant windows are not searched. |
| RealGetWindowClassA Retrieves a string that specifies the window type. (ANSI) |
| RealGetWindowClassW Retrieves a string that specifies the window type. (Unicode) |
| RegisterClassA Registers a window class for subsequent use in calls to the CreateWindow or CreateWindowEx function. (RegisterClassA) |
| RegisterClassExA Registers a window class for subsequent use in calls to the CreateWindow or CreateWindowEx function. (RegisterClassExA) |
| RegisterClassExW Registers a window class for subsequent use in calls to the CreateWindow or CreateWindowEx function. (RegisterClassExW) |
| RegisterClassW Registers a window class for subsequent use in calls to the CreateWindow or CreateWindowEx function. (RegisterClassW) |
| RegisterShellHookWindow Registers a specified Shell window to receive certain messages for events or notifications that are useful to Shell applications. |
| RegisterWindowMessageA Defines a new window message that is guaranteed to be unique throughout the system. The message value can be used when sending or posting messages. (ANSI) |
| RegisterWindowMessageW Defines a new window message that is guaranteed to be unique throughout the system. The message value can be used when sending or posting messages. (Unicode) |
| RemovePropA Removes an entry from the property list of the specified window. The specified character string identifies the entry to be removed. (ANSI) |
| RemovePropW Removes an entry from the property list of the specified window. The specified character string identifies the entry to be removed. (Unicode) |
| ReplyMessage Replies to a message sent from another thread by the SendMessage function. |
| SENDASYNCPROC An application-defined callback function used with the SendMessageCallback function. |
| SendMessage The SendMessage function sends the specified message to a window or windows. (SendMessage function) |
| SendMessageA Sends the specified message to a window or windows. The SendMessage function calls the window procedure for the specified window and does not return until the window procedure has processed the message. (SendMessageA) |
| SendMessageCallbackA Sends the specified message to a window or windows. (SendMessageCallbackA) |
| SendMessageCallbackW Sends the specified message to a window or windows. (SendMessageCallbackW) |
| SendMessageTimeoutA Sends the specified message to one or more windows. (ANSI) |
| SendMessageTimeoutW Sends the specified message to one or more windows. (Unicode) |
| SendMessageW The SendMessageW (Unicode) function sends the specified message to a window or windows. (SendMessageW) |
| SendNotifyMessageA Sends the specified message to a window or windows. (SendNotifyMessageA) |
| SendNotifyMessageW Sends the specified message to a window or windows. (SendNotifyMessageW) |
| SetAdditionalForegroundBoostProcesses SetAdditionalForegroundBoostProcesses is a performance assist API to help applications with a multi-process application model where multiple processes contribute to a foreground experience, either as data or rendering. |
| SetClassLongA Replaces the specified 32-bit (long) value at the specified offset into the extra class memory or the WNDCLASSEX structure for the class to which the specified window belongs. (ANSI) |
| SetClassLongPtrA Replaces the specified value at the specified offset in the extra class memory or the WNDCLASSEX structure for the class to which the specified window belongs. (ANSI) |
| SetClassLongPtrW Replaces the specified value at the specified offset in the extra class memory or the WNDCLASSEX structure for the class to which the specified window belongs. (Unicode) |
| SetClassLongW Replaces the specified 32-bit (long) value at the specified offset into the extra class memory or the WNDCLASSEX structure for the class to which the specified window belongs. (Unicode) |
| SetClassWord Replaces the 16-bit (WORD) value at the specified offset into the extra class memory for the window class to which the specified window belongs. |
| SetCoalescableTimer Creates a timer with the specified time-out value and coalescing tolerance delay. |
| SetForegroundWindow Brings the thread that created the specified window into the foreground and activates the window. |
| SetLayeredWindowAttributes Sets the opacity and transparency color key of a layered window. |
| SetMessageExtraInfo Sets the extra message information for the current thread. |
| SetParent Changes the parent window of the specified child window. |
| SetProcessDefaultLayout Changes the default layout when windows are created with no parent or owner only for the currently running process. |
| SetProcessDPIAware SetProcessDPIAware may be altered or unavailable. Instead, use SetProcessDPIAwareness. |
| SetPropA Adds a new entry or changes an existing entry in the property list of the specified window. (ANSI) |
| SetPropW Adds a new entry or changes an existing entry in the property list of the specified window. (Unicode) |
| SetSysColors Sets the colors for the specified display elements. |
| SetTimer Creates a timer with the specified time-out value. |
| SetWindowDisplayAffinity Stores the display affinity setting in kernel mode on the hWnd associated with the window. |
| SetWindowLongA Changes an attribute of the specified window. The function also sets the 32-bit (long) value at the specified offset into the extra window memory. (ANSI) |
| SetWindowLongPtrA Changes an attribute of the specified window. (ANSI) |
| SetWindowLongPtrW Changes an attribute of the specified window. (Unicode) |
| SetWindowLongW Changes an attribute of the specified window. The function also sets the 32-bit (long) value at the specified offset into the extra window memory. (Unicode) |
| SetWindowPlacement Sets the show state and the restored, minimized, and maximized positions of the specified window. |
| SetWindowPos Changes the size, position, and Z order of a child, pop-up, or top-level window. These windows are ordered according to their appearance on the screen. The topmost window receives the highest rank and is the first window in the Z order. |
| SetWindowsHookExA Installs an application-defined hook procedure into a hook chain. (ANSI) |
| SetWindowsHookExW Installs an application-defined hook procedure into a hook chain. (Unicode) |
| SetWindowTextA Changes the text of the specified window's title bar (if it has one). If the specified window is a control, the text of the control is changed. However, SetWindowText cannot change the text of a control in another application. (ANSI) |
| SetWindowTextW Changes the text of the specified window's title bar (if it has one). If the specified window is a control, the text of the control is changed. However, SetWindowText cannot change the text of a control in another application. (Unicode) |
| ShowOwnedPopups Shows or hides all pop-up windows owned by the specified window. |
| ShowWindow Sets the specified window's show state. |
| ShowWindowAsync Sets the show state of a window without waiting for the operation to complete. |
| SoundSentry Triggers a visual signal to indicate that a sound is playing. |
| SwitchToThisWindow Switches focus to the specified window and brings it to the foreground. |
| SystemParametersInfoA Retrieves or sets the value of one of the system-wide parameters. (ANSI) |
| SystemParametersInfoW Retrieves or sets the value of one of the system-wide parameters. (Unicode) |
| TileWindows Tiles the specified child windows of the specified parent window. |
| TIMERPROC An application-defined callback function that processes WM_TIMER messages. The TIMERPROC type defines a pointer to this callback function. TimerProc is a placeholder for the application-defined function name. |
| TranslateMDISysAccel Processes accelerator keystrokes for window menu commands of the multiple-document interface (MDI) child windows associated with the specified MDI client window. |
| TranslateMessage Translates virtual-key messages into character messages. The character messages are posted to the calling thread's message queue, to be read the next time the thread calls the GetMessage or PeekMessage function. |
| UnhookWindowsHookEx Removes a hook procedure installed in a hook chain by the SetWindowsHookEx function. |
| UnregisterClassA Unregisters a window class, freeing the memory required for the class. (ANSI) |
| UnregisterClassW Unregisters a window class, freeing the memory required for the class. (Unicode) |
| UpdateLayeredWindow Updates the position, size, shape, content, and translucency of a layered window. |
| WaitMessage Yields control to other threads when a thread has no other messages in its message queue. The WaitMessage function suspends the thread and does not return until a new message is placed in the thread's message queue. |
| WindowFromPhysicalPoint Retrieves a handle to the window that contains the specified physical point. |
| WindowFromPoint Retrieves a handle to the window that contains the specified point. |
| WinMain The user-provided entry point for a graphical Windows-based application. |
| WNDPROC A callback function, which you define in your application, that processes messages sent to a window. |
Structures
| ALTTABINFO Contains status information for the application-switching (ALT+TAB) window. |
| ANIMATIONINFO Describes the animation effects associated with user actions. |
| AUDIODESCRIPTION Contains information associated with audio descriptions. This structure is used with the SystemParametersInfo function when the SPI_GETAUDIODESCRIPTION or SPI_SETAUDIODESCRIPTION action value is specified. |
| BSMINFO Contains information about a window that denied a request from BroadcastSystemMessageEx. |
| CBT_CREATEWNDA Contains information passed to a WH_CBT hook procedure, CBTProc, before a window is created. (ANSI) |
| CBT_CREATEWNDW Contains information passed to a WH_CBT hook procedure, CBTProc, before a window is created. (Unicode) |
| CBTACTIVATESTRUCT Contains information passed to a WH_CBT hook procedure, CBTProc, before a window is activated. |
| CHANGEFILTERSTRUCT Contains extended result information obtained by calling the ChangeWindowMessageFilterEx function. |
| CLIENTCREATESTRUCT Contains information about the menu and first multiple-document interface (MDI) child window of an MDI client window. |
| CREATESTRUCTA Defines the initialization parameters passed to the window procedure of an application. These members are identical to the parameters of the CreateWindowEx function. (ANSI) |
| CREATESTRUCTW Defines the initialization parameters passed to the window procedure of an application. These members are identical to the parameters of the CreateWindowEx function. (Unicode) |
| CWPRETSTRUCT Defines the message parameters passed to a WH_CALLWNDPROCRET hook procedure, CallWndRetProc. |
| CWPSTRUCT Defines the message parameters passed to a WH_CALLWNDPROC hook procedure, CallWndProc. |
| DEBUGHOOKINFO Contains debugging information passed to a WH_DEBUG hook procedure, DebugProc. |
| EVENTMSG Contains information about a hardware message sent to the system message queue. This structure is used to store message information for the JournalPlaybackProc callback function. |
| GUITHREADINFO Contains information about a GUI thread. |
| KBDLLHOOKSTRUCT Contains information about a low-level keyboard input event. |
| MDICREATESTRUCTA Contains information about the class, title, owner, location, and size of a multiple-document interface (MDI) child window. (ANSI) |
| MDICREATESTRUCTW Contains information about the class, title, owner, location, and size of a multiple-document interface (MDI) child window. (Unicode) |
| MINIMIZEDMETRICS Contains the scalable metrics associated with minimized windows. |
| MINMAXINFO Contains information about a window's maximized size and position and its minimum and maximum tracking size. |
| MOUSEHOOKSTRUCT Contains information about a mouse event passed to a WH_MOUSE hook procedure, MouseProc. |
| MOUSEHOOKSTRUCTEX Contains information about a mouse event passed to a WH_MOUSE hook procedure, MouseProc. This is an extension of the MOUSEHOOKSTRUCT structure that includes information about wheel movement or the use of the X button. |
| MSG Contains message information from a thread's message queue. |
| MSLLHOOKSTRUCT Contains information about a low-level mouse input event. |
| NCCALCSIZE_PARAMS Contains information that an application can use while processing the WM_NCCALCSIZE message to calculate the size, position, and valid contents of the client area of a window. |
| NONCLIENTMETRICSA Contains the scalable metrics associated with the nonclient area of a nonminimized window. (ANSI) |
| NONCLIENTMETRICSW Contains the scalable metrics associated with the nonclient area of a nonminimized window. (Unicode) |
| STYLESTRUCT Contains the styles for a window. |
| TITLEBARINFO Contains title bar information. |
| TITLEBARINFOEX Expands on the information described in the TITLEBARINFO structure by including the coordinates of each element of the title bar. |
| UPDATELAYEREDWINDOWINFO Used by UpdateLayeredWindowIndirect to provide position, size, shape, content, and translucency information for a layered window. |
| WINDOWINFO Contains window information. |
| WINDOWPLACEMENT Contains information about the placement of a window on the screen. |
| WINDOWPOS Contains information about the size and position of a window. |
| WNDCLASSA Contains the window class attributes that are registered by the RegisterClass function. (ANSI) |
| WNDCLASSEXA Contains window class information. (ANSI) |
| WNDCLASSEXW Contains window class information. (Unicode) |
| WNDCLASSW Contains the window class attributes that are registered by the RegisterClass function. (Unicode) |