C# Signature:
[DllImport("user32.dll")]
static extern IntPtr SetWinEventHook(WinEvents eventMin, WinEvents eventMax, IntPtr
hmodWinEventProc, WinEventDelegate lpfnWinEventProc, uint idProcess,
uint idThread, WinEventFlags dwFlags);
VB Signature:
<System.Runtime.InteropServices.DllImport("user32.dll", EntryPoint:="SetWinEventHook")> _
Private Shared Function SetWinEventHook( _
ByVal eventMin As UInteger, _
ByVal eventMax As UInteger, _
ByVal hmodWinEventProc As IntPtr, _
ByVal lpfnWinEventProc As WinEventDelegate, _
ByVal idProcess As UInteger, _
ByVal idThread As UInteger, _
ByVal dwFlags As UInteger _
) As IntPtr
End Function
User-Defined Types:
C# Constants:
public enum WinEventFlags : uint
{
WINEVENT_OUTOFCONTEXT = 0x0000, // Events are ASYNC
WINEVENT_SKIPOWNTHREAD = 0x0001, // Don't call back for events on installer's thread
WINEVENT_SKIPOWNPROCESS = 0x0002, // Don't call back for events on installer's process
WINEVENT_INCONTEXT = 0x0004, // Events are SYNC, this causes your dll to be injected into every process
}
public enum WinEvents : uint
{
/** The range of WinEvent constant values specified by the Accessibility Interoperability Alliance (AIA) for use across the industry.
* For more information, see Allocation of WinEvent IDs.
*/
EVENT_AIA_START = 0xA000,
EVENT_AIA_END = 0xAFFF,
/** The lowest and highest possible event values.
*/
EVENT_MIN = 0x00000001,
EVENT_MAX = 0x7FFFFFFF,
/** An object's KeyboardShortcut property has changed. Server applications send this event for their accessible objects.
*/
EVENT_OBJECT_ACCELERATORCHANGE = 0x8012,
/** Sent when a window is cloaked. A cloaked window still exists, but is invisible to the user.
*/
EVENT_OBJECT_CLOAKED = 0x8017,
/** A window object's scrolling has ended. Unlike EVENT_SYSTEM_SCROLLEND, this event is associated with the scrolling window.
* Whether the scrolling is horizontal or vertical scrolling, this event should be sent whenever the scroll action is completed.
* The hwnd parameter of the WinEventProc callback function describes the scrolling window; the idObject parameter is OBJID_CLIENT,
* and the idChild parameter is CHILDID_SELF.
*/
EVENT_OBJECT_CONTENTSCROLLED = 0x8015,
/** An object has been created. The system sends this event for the following user interface elements: caret, header control,
* list-view control, tab control, toolbar control, tree view control, and window object. Server applications send this event
* for their accessible objects.
* Before sending the event for the parent object, servers must send it for all of an object's child objects.
* Servers must ensure that all child objects are fully created and ready to accept IAccessible calls from clients before
* the parent object sends this event.
* Because a parent object is created after its child objects, clients must make sure that an object's parent has been created
* before calling IAccessible::get_accParent, particularly if in-context hook functions are used.
*/
EVENT_OBJECT_CREATE = 0x8000,
/** An object's DefaultAction property has changed. The system sends this event for dialog boxes. Server applications send
* this event for their accessible objects.
*/
EVENT_OBJECT_DEFACTIONCHANGE = 0x8011,
/** An object's Description property has changed. Server applications send this event for their accessible objects.
*/
EVENT_OBJECT_DESCRIPTIONCHANGE = 0x800D,
/** An object has been destroyed. The system sends this event for the following user interface elements: caret, header control,
* list-view control, tab control, toolbar control, tree view control, and window object. Server applications send this event for
* their accessible objects.
* Clients assume that all of an object's children are destroyed when the parent object sends this event.
* After receiving this event, clients do not call an object's IAccessible properties or methods. However, the interface pointer
* must remain valid as long as there is a reference count on it (due to COM rules), but the UI element may no longer be present.
* Further calls on the interface pointer may return failure errors; to prevent this, servers create proxy objects and monitor
* their life spans.
*/
EVENT_OBJECT_DESTROY = 0x8001,
/** The user started to drag an element. The hwnd, idObject, and idChild parameters of the WinEventProc callback function
* identify the object being dragged.
*/
EVENT_OBJECT_DRAGSTART = 0x8021,
/** The user has ended a drag operation before dropping the dragged element on a drop target. The hwnd, idObject, and idChild
* parameters of the WinEventProc callback function identify the object being dragged.
*/
EVENT_OBJECT_DRAGCANCEL = 0x8022,
/** The user dropped an element on a drop target. The hwnd, idObject, and idChild parameters of the WinEventProc callback
* function identify the object being dragged.
*/
EVENT_OBJECT_DRAGCOMPLETE = 0x8023,
/** The user dragged an element into a drop target's boundary. The hwnd, idObject, and idChild parameters of the WinEventProc
* callback function identify the drop target.
*/
EVENT_OBJECT_DRAGENTER = 0x8024,
/** The user dragged an element out of a drop target's boundary. The hwnd, idObject, and idChild parameters of the WinEventProc
* callback function identify the drop target.
*/
EVENT_OBJECT_DRAGLEAVE = 0x8025,
/** The user dropped an element on a drop target. The hwnd, idObject, and idChild parameters of the WinEventProc callback
* function identify the drop target.
*/
EVENT_OBJECT_DRAGDROPPED = 0x8026,
/** The highest object event value.
*/
EVENT_OBJECT_END = 0x80FF,
/** An object has received the keyboard focus. The system sends this event for the following user interface elements:
* list-view control, menu bar, pop-up menu, switch window, tab control, tree view control, and window object.
* Server applications send this event for their accessible objects.
* The hwnd parameter of the WinEventProc callback function identifies the window that receives the keyboard focus.
*/
EVENT_OBJECT_FOCUS = 0x8005,
/** An object's Help property has changed. Server applications send this event for their accessible objects.
*/
EVENT_OBJECT_HELPCHANGE = 0x8010,
/** An object is hidden. The system sends this event for the following user interface elements: caret and cursor.
* Server applications send this event for their accessible objects.
* When this event is generated for a parent object, all child objects are already hidden.
* Server applications do not send this event for the child objects.
* Hidden objects include the STATE_SYSTEM_INVISIBLE flag; shown objects do not include this flag. The EVENT_OBJECT_HIDE event
* also indicates that the STATE_SYSTEM_INVISIBLE flag is set. Therefore, servers do not send the EVENT_STATE_CHANGE event in
* this case.
*/
EVENT_OBJECT_HIDE = 0x8003,
/** A window that hosts other accessible objects has changed the hosted objects. A client might need to query the host
* window to discover the new hosted objects, especially if the client has been monitoring events from the window.
* A hosted object is an object from an accessibility framework (MSAA or UI Automation) that is different from that of the host.
* Changes in hosted objects that are from the same framework as the host should be handed with the structural change events,
* such as EVENT_OBJECT_CREATE for MSAA. For more info see comments within winuser.h.
*/
EVENT_OBJECT_HOSTEDOBJECTSINVALIDATED = 0x8020,
/** An IME window has become hidden.
*/
EVENT_OBJECT_IME_HIDE = 0x8028,
/** An IME window has become visible.
*/
EVENT_OBJECT_IME_SHOW = 0x8027,
/** The size or position of an IME window has changed.
*/
EVENT_OBJECT_IME_CHANGE = 0x8029,
/** An object has been invoked; for example, the user has clicked a button. This event is supported by common controls and is
* used by UI Automation.
* For this event, the hwnd, ID, and idChild parameters of the WinEventProc callback function identify the item that is invoked.
*/
EVENT_OBJECT_INVOKED = 0x8013,
/** An object that is part of a live region has changed. A live region is an area of an application that changes frequently
* and/or asynchronously.
*/
EVENT_OBJECT_LIVEREGIONCHANGED = 0x8019,
/** An object has changed location, shape, or size. The system sends this event for the following user interface elements:
* caret and window objects. Server applications send this event for their accessible objects.
* This event is generated in response to a change in the top-level object within the object hierarchy; it is not generated for any
* children that the object might have. For example, if the user resizes a window, the system sends this notification for the window,
* but not for the menu bar, title bar, scroll bar, or other objects that have also changed.
* The system does not send this event for every non-floating child window when the parent moves. However, if an application explicitly
* resizes child windows as a result of resizing the parent window, the system sends multiple events for the resized children.
* If an object's State property is set to STATE_SYSTEM_FLOATING, the server sends EVENT_OBJECT_LOCATIONCHANGE whenever the object changes
* location. If an object does not have this state, servers only trigger this event when the object moves in relation to its parent.
* For this event notification, the idChild parameter of the WinEventProc callback function identifies the child object that has changed.
*/
EVENT_OBJECT_LOCATIONCHANGE = 0x800B,
/** An object's Name property has changed. The system sends this event for the following user interface elements: check box,
* cursor, list-view control, push button, radio button, status bar control, tree view control, and window object. Server
*
* applications send this event for their accessible objects.
*/
EVENT_OBJECT_NAMECHANGE = 0x800C,
/** An object has a new parent object. Server applications send this event for their accessible objects.
*/
EVENT_OBJECT_PARENTCHANGE = 0x800F,
/** A container object has added, removed, or reordered its children. The system sends this event for the following user
* interface elements: header control, list-view control, toolbar control, and window object. Server applications send this
* event as appropriate for their accessible objects.
* For example, this event is generated by a list-view object when the number of child elements or the order of the elements changes.
* This event is also sent by a parent window when the Z-order for the child windows changes.
*/
EVENT_OBJECT_REORDER = 0x8004,
/** The selection within a container object has changed. The system sends this event for the following user interface elements:
* list-view control, tab control, tree view control, and window object. Server applications send this event for their accessible
* objects.
* This event signals a single selection: either a child is selected in a container that previously did not contain any selected children,
* or the selection has changed from one child to another.
* The hwnd and idObject parameters of the WinEventProc callback function describe the container; the idChild parameter identifies the object
* that is selected. If the selected child is a window that also contains objects, the idChild parameter is OBJID_WINDOW.
*/
EVENT_OBJECT_SELECTION = 0x8006,
/** A child within a container object has been added to an existing selection. The system sends this event for the following user
* interface elements: list box, list-view control, and tree view control. Server applications send this event for their accessible
* objects.
* The hwnd and idObject parameters of the WinEventProc callback function describe the container. The idChild parameter is the child that
* is added to the selection.
*/
EVENT_OBJECT_SELECTIONADD = 0x8007,
/** An item within a container object has been removed from the selection. The system sends this event for the following user
* interface elements: list box, list-view control, and tree view control. Server applications send this event for their accessible
* objects.
* This event signals that a child is removed from an existing selection.
* The hwnd and idObject parameters of the WinEventProc callback function describe the container; the idChild parameter identifies
* the child that has been removed from the selection.
*/
EVENT_OBJECT_SELECTIONREMOVE = 0x8008,
/** Numerous selection changes have occurred within a container object. The system sends this event for list boxes; server
* applications send it for their accessible objects.
* This event is sent when the selected items within a control have changed substantially. The event informs the client
* that many selection changes have occurred, and it is sent instead of several
* EVENT_OBJECT_SELECTIONADD or EVENT_OBJECT_SELECTIONREMOVE events. The client
* queries for the selected items by calling the container object's IAccessible::get_accSelection method and
* enumerating the selected items. For this event notification, the hwnd and idObject parameters of the WinEventProc callback
* function describe the container in which the changes occurred.
*/
EVENT_OBJECT_SELECTIONWITHIN = 0x8009,
/** A hidden object is shown. The system sends this event for the following user interface elements: caret, cursor, and window
* object. Server applications send this event for their accessible objects.
* Clients assume that when this event is sent by a parent object, all child objects are already displayed.
* Therefore, server applications do not send this event for the child objects.
* Hidden objects include the STATE_SYSTEM_INVISIBLE flag; shown objects do not include this flag.
* The EVENT_OBJECT_SHOW event also indicates that the STATE_SYSTEM_INVISIBLE flag is cleared. Therefore, servers
* do not send the EVENT_STATE_CHANGE event in this case.
*/
EVENT_OBJECT_SHOW = 0x8002,
/** An object's state has changed. The system sends this event for the following user interface elements: check box, combo box,
* header control, push button, radio button, scroll bar, toolbar control, tree view control, up-down control, and window object.
* Server applications send this event for their accessible objects.
* For example, a state change occurs when a button object is clicked or released, or when an object is enabled or disabled.
* For this event notification, the idChild parameter of the WinEventProc callback function identifies the child object whose state has changed.
*/
EVENT_OBJECT_STATECHANGE = 0x800A,
/** The conversion target within an IME composition has changed. The conversion target is the subset of the IME composition
* which is actively selected as the target for user-initiated conversions.
*/
EVENT_OBJECT_TEXTEDIT_CONVERSIONTARGETCHANGED = 0x8030,
/** An object's text selection has changed. This event is supported by common controls and is used by UI Automation.
* The hwnd, ID, and idChild parameters of the WinEventProc callback function describe the item that is contained in the updated text selection.
*/
EVENT_OBJECT_TEXTSELECTIONCHANGED = 0x8014,
/** Sent when a window is uncloaked. A cloaked window still exists, but is invisible to the user.
*/
EVENT_OBJECT_UNCLOAKED = 0x8018,
/** An object's Value property has changed. The system sends this event for the user interface elements that include the scroll
* bar and the following controls: edit, header, hot key, progress bar, slider, and up-down. Server applications send this event
* for their accessible objects.
*/
EVENT_OBJECT_VALUECHANGE = 0x800E,
/** The range of event constant values reserved for OEMs. For more information, see Allocation of WinEvent IDs.
*/
EVENT_OEM_DEFINED_START = 0x0101,
EVENT_OEM_DEFINED_END = 0x01FF,
/** An alert has been generated. Server applications should not send this event.
*/
EVENT_SYSTEM_ALERT = 0x0002,
/** A preview rectangle is being displayed.
*/
EVENT_SYSTEM_ARRANGMENTPREVIEW = 0x8016,
/** A window has lost mouse capture. This event is sent by the system, never by servers.
*/
EVENT_SYSTEM_CAPTUREEND = 0x0009,
/** A window has received mouse capture. This event is sent by the system, never by servers.
*/
EVENT_SYSTEM_CAPTURESTART = 0x0008,
/** A window has exited context-sensitive Help mode. This event is not sent consistently by the system.
*/
EVENT_SYSTEM_CONTEXTHELPEND = 0x000D,
/** A window has entered context-sensitive Help mode. This event is not sent consistently by the system.
*/
EVENT_SYSTEM_CONTEXTHELPSTART = 0x000C,
/** The active desktop has been switched.
*/
EVENT_SYSTEM_DESKTOPSWITCH = 0x0020,
/** A dialog box has been closed. The system sends this event for standard dialog boxes; servers send it for custom dialog boxes.
* This event is not sent consistently by the system.
*/
EVENT_SYSTEM_DIALOGEND = 0x0011,
/** A dialog box has been displayed. The system sends this event for standard dialog boxes, which are created using resource
* templates or Win32 dialog box functions. Servers send this event for custom dialog boxes, which are windows that function as
* dialog boxes but are not created in the standard way.
* This event is not sent consistently by the system.
*/
EVENT_SYSTEM_DIALOGSTART = 0x0010,
/** An application is about to exit drag-and-drop mode. Applications that support drag-and-drop operations must send this event;
* the system does not send this event.
*/
EVENT_SYSTEM_DRAGDROPEND = 0x000F,
/** An application is about to enter drag-and-drop mode. Applications that support drag-and-drop operations must send this
* event because the system does not send it.
*/
EVENT_SYSTEM_DRAGDROPSTART = 0x000E,
/** The highest system event value.
*/
EVENT_SYSTEM_END = 0x00FF,
/** The foreground window has changed. The system sends this event even if the foreground window has changed to another window
* in the same thread. Server applications never send this event.
* For this event, the WinEventProc callback function's hwnd parameter is the handle to the window that is in the
* foreground, the idObject parameter is OBJID_WINDOW, and the idChild parameter is CHILDID_SELF.
*/
EVENT_SYSTEM_FOREGROUND = 0x0003,
/** A pop-up menu has been closed. The system sends this event for standard menus; servers send it for custom menus.
* When a pop-up menu is closed, the client receives this message, and then the EVENT_SYSTEM_MENUEND event.
* This event is not sent consistently by the system.
*/
EVENT_SYSTEM_MENUPOPUPEND = 0x0007,
/** A pop-up menu has been displayed. The system sends this event for standard menus, which are identified by HMENU, and are
* created using menu-template resources or Win32 menu functions. Servers send this event for custom menus, which are user
* interface elements that function as menus but are not created in the standard way. This event is not sent consistently by the system.
*/
EVENT_SYSTEM_MENUPOPUPSTART = 0x0006,
/** A menu from the menu bar has been closed. The system sends this event for standard menus; servers send it for custom menus.
* For this event, the WinEventProc callback function's hwnd, idObject, and idChild parameters refer to the control
* that contains the menu bar or the control that activates the context menu. The hwnd parameter is the handle to the window
* that is related to the event. The idObject parameter is OBJID_MENU or OBJID_SYSMENU for a menu, or OBJID_WINDOW for a
* pop-up menu. The idChild parameter is CHILDID_SELF.
*/
EVENT_SYSTEM_MENUEND = 0x0005,
/** A menu item on the menu bar has been selected. The system sends this event for standard menus, which are identified
* by HMENU, created using menu-template resources or Win32 menu API elements. Servers send this event for custom menus,
* which are user interface elements that function as menus but are not created in the standard way.
* For this event, the WinEventProc callback function's hwnd, idObject, and idChild parameters refer to the control
* that contains the menu bar or the control that activates the context menu. The hwnd parameter is the handle to the window
* related to the event. The idObject parameter is OBJID_MENU or OBJID_SYSMENU for a menu, or OBJID_WINDOW for a pop-up menu.
* The idChild parameter is CHILDID_SELF.The system triggers more than one EVENT_SYSTEM_MENUSTART event that does not always
* correspond with the EVENT_SYSTEM_MENUEND event.
*/
EVENT_SYSTEM_MENUSTART = 0x0004,
/** A window object is about to be restored. This event is sent by the system, never by servers.
*/
EVENT_SYSTEM_MINIMIZEEND = 0x0017,
/** A window object is about to be minimized. This event is sent by the system, never by servers.
*/
EVENT_SYSTEM_MINIMIZESTART = 0x0016,
/** The movement or resizing of a window has finished. This event is sent by the system, never by servers.
*/
EVENT_SYSTEM_MOVESIZEEND = 0x000B,
/** A window is being moved or resized. This event is sent by the system, never by servers.
*/
EVENT_SYSTEM_MOVESIZESTART = 0x000A,
/** Scrolling has ended on a scroll bar. This event is sent by the system for standard scroll bar controls and for
* scroll bars that are attached to a window. Servers send this event for custom scroll bars, which are user interface
* elements that function as scroll bars but are not created in the standard way.
* The idObject parameter that is sent to the WinEventProc callback function is OBJID_HSCROLL for horizontal scroll bars, and
* OBJID_VSCROLL for vertical scroll bars.
*/
EVENT_SYSTEM_SCROLLINGEND = 0x0013,
/** Scrolling has started on a scroll bar. The system sends this event for standard scroll bar controls and for scroll
* bars attached to a window. Servers send this event for custom scroll bars, which are user interface elements that
* function as scroll bars but are not created in the standard way.
* The idObject parameter that is sent to the WinEventProc callback function is OBJID_HSCROLL for horizontal scrolls bars,
* and OBJID_VSCROLL for vertical scroll bars.
*/
EVENT_SYSTEM_SCROLLINGSTART = 0x0012,
/** A sound has been played. The system sends this event when a system sound, such as one for a menu,
* is played even if no sound is audible (for example, due to the lack of a sound file or a sound card).
* Servers send this event whenever a custom UI element generates a sound.
* For this event, the WinEventProc callback function receives the OBJID_SOUND value as the idObject parameter.
*/
EVENT_SYSTEM_SOUND = 0x0001,
/** The user has released ALT+TAB. This event is sent by the system, never by servers.
* The hwnd parameter of the WinEventProc callback function identifies the window to which the user has switched.
* If only one application is running when the user presses ALT+TAB, the system sends this event without a corresponding
* EVENT_SYSTEM_SWITCHSTART event.
*/
EVENT_SYSTEM_SWITCHEND = 0x0015,
/** The user has pressed ALT+TAB, which activates the switch window. This event is sent by the system, never by servers.
* The hwnd parameter of the WinEventProc callback function identifies the window to which the user is switching.
* If only one application is running when the user presses ALT+TAB, the system sends an EVENT_SYSTEM_SWITCHEND event without a
* corresponding EVENT_SYSTEM_SWITCHSTART event.
*/
EVENT_SYSTEM_SWITCHSTART = 0x0014,
/** The range of event constant values reserved for UI Automation event identifiers. For more information,
* see Allocation of WinEvent IDs.
*/
EVENT_UIA_EVENTID_START = 0x4E00,
EVENT_UIA_EVENTID_END = 0x4EFF,
/**
* The range of event constant values reserved for UI Automation property-changed event identifiers.
* For more information, see Allocation of WinEvent IDs.
*/
EVENT_UIA_PROPID_START = 0x7500,
EVENT_UIA_PROPID_END = 0x75FF
}
Notes:
The MSDN documentation states:
When you use a Win32 API that has a callback in managed code, such as SetWinEventHook, you should use GCHandle class structure to avoid exceptions.
This is apparently not accurate as the P/Invoke layer automatically generates a marshaling stub at a fixed address:
http://blogs.msdn.com/cbrumme/archive/2003/05/06/51385.aspx
Tips & Tricks:
Please add some!
Sample Code:
Please add some!
Alternative Managed API:
The ManagedWindowsApi project (http://mwinapi.sourceforge.net) provides a SystemAccessibleObject class to access accessible objects and handle accessible events.
