C# Signature:

[DllImport("user32.dll")]
static extern IntPtr SetWinEventHook(uint eventMin, uint eventMax, IntPtr
   hmodWinEventProc, WinEventDelegate lpfnWinEventProc, uint idProcess,
   uint idThread, uint 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:

WinEventDelegate

C# Constants:

const uint WINEVENT_OUTOFCONTEXT = 0x0000; // Events are ASYNC

const uint WINEVENT_SKIPOWNTHREAD = 0x0001; // Don't call back for events on installer's thread

const uint WINEVENT_SKIPOWNPROCESS = 0x0002; // Don't call back for events on installer's process

const uint WINEVENT_INCONTEXT = 0x0004; // Events are SYNC, this causes your dll to be injected into every process

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

const uint EVENT_MIN = 0x00000001;

const uint EVENT_MAX = 0x7FFFFFFF;

const uint EVENT_SYSTEM_SOUND = 0x0001;

const uint EVENT_SYSTEM_ALERT = 0x0002;

const uint EVENT_SYSTEM_FOREGROUND = 0x0003;

const uint EVENT_SYSTEM_MENUSTART = 0x0004;

const uint EVENT_SYSTEM_MENUEND = 0x0005;

const uint EVENT_SYSTEM_MENUPOPUPSTART = 0x0006;

const uint EVENT_SYSTEM_MENUPOPUPEND = 0x0007;

const uint EVENT_SYSTEM_CAPTURESTART = 0x0008;

const uint EVENT_SYSTEM_CAPTUREEND = 0x0009;

const uint EVENT_SYSTEM_MOVESIZESTART = 0x000A;

const uint EVENT_SYSTEM_MOVESIZEEND = 0x000B;

const uint EVENT_SYSTEM_CONTEXTHELPSTART = 0x000C;

const uint EVENT_SYSTEM_CONTEXTHELPEND = 0x000D;

const uint EVENT_SYSTEM_DRAGDROPSTART = 0x000E;

const uint EVENT_SYSTEM_DRAGDROPEND = 0x000F;

const uint EVENT_SYSTEM_DIALOGSTART = 0x0010;

const uint EVENT_SYSTEM_DIALOGEND = 0x0011;

const uint EVENT_SYSTEM_SCROLLINGSTART = 0x0012;

const uint EVENT_SYSTEM_SCROLLINGEND = 0x0013;

const uint EVENT_SYSTEM_SWITCHSTART = 0x0014;

const uint EVENT_SYSTEM_SWITCHEND = 0x0015;

const uint EVENT_SYSTEM_MINIMIZESTART = 0x0016;

const uint EVENT_SYSTEM_MINIMIZEEND = 0x0017;

const uint EVENT_SYSTEM_DESKTOPSWITCH = 0x0020;

const uint EVENT_SYSTEM_END = 0x00FF;

const uint EVENT_OEM_DEFINED_START = 0x0101;

const uint EVENT_OEM_DEFINED_END = 0x01FF;

const uint EVENT_UIA_EVENTID_START = 0x4E00;

const uint EVENT_UIA_EVENTID_END = 0x4EFF;

const uint EVENT_UIA_PROPID_START = 0x7500;

const uint EVENT_UIA_PROPID_END = 0x75FF;

const uint EVENT_CONSOLE_CARET = 0x4001;

const uint EVENT_CONSOLE_UPDATE_REGION = 0x4002;

const uint EVENT_CONSOLE_UPDATE_SIMPLE = 0x4003;

const uint EVENT_CONSOLE_UPDATE_SCROLL = 0x4004;

const uint EVENT_CONSOLE_LAYOUT = 0x4005;

const uint EVENT_CONSOLE_START_APPLICATION = 0x4006;

const uint EVENT_CONSOLE_END_APPLICATION = 0x4007;

const uint EVENT_CONSOLE_END = 0x40FF;

const uint EVENT_OBJECT_CREATE = 0x8000; // hwnd ID idChild is created item

const uint EVENT_OBJECT_DESTROY = 0x8001; // hwnd ID idChild is destroyed item

const uint EVENT_OBJECT_SHOW = 0x8002; // hwnd ID idChild is shown item

const uint EVENT_OBJECT_HIDE = 0x8003; // hwnd ID idChild is hidden item

const uint EVENT_OBJECT_REORDER = 0x8004; // hwnd ID idChild is parent of zordering children

const uint EVENT_OBJECT_FOCUS = 0x8005; // hwnd ID idChild is focused item

const uint EVENT_OBJECT_SELECTION = 0x8006; // hwnd ID idChild is selected item (if only one), or idChild is OBJID_WINDOW if complex

const uint EVENT_OBJECT_SELECTIONADD = 0x8007; // hwnd ID idChild is item added

const uint EVENT_OBJECT_SELECTIONREMOVE = 0x8008; // hwnd ID idChild is item removed

const uint EVENT_OBJECT_SELECTIONWITHIN = 0x8009; // hwnd ID idChild is parent of changed selected items

const uint EVENT_OBJECT_STATECHANGE = 0x800A; // hwnd ID idChild is item w/ state change

const uint EVENT_OBJECT_LOCATIONCHANGE = 0x800B; // hwnd ID idChild is moved/sized item

const uint EVENT_OBJECT_NAMECHANGE = 0x800C; // hwnd ID idChild is item w/ name change

const uint EVENT_OBJECT_DESCRIPTIONCHANGE = 0x800D; // hwnd ID idChild is item w/ desc change

const uint EVENT_OBJECT_VALUECHANGE = 0x800E; // hwnd ID idChild is item w/ value change

const uint EVENT_OBJECT_PARENTCHANGE = 0x800F; // hwnd ID idChild is item w/ new parent

const uint EVENT_OBJECT_HELPCHANGE = 0x8010; // hwnd ID idChild is item w/ help change

const uint EVENT_OBJECT_DEFACTIONCHANGE = 0x8011; // hwnd ID idChild is item w/ def action change

const uint EVENT_OBJECT_ACCELERATORCHANGE = 0x8012; // hwnd ID idChild is item w/ keybd accel change

const uint EVENT_OBJECT_INVOKED = 0x8013; // hwnd ID idChild is item invoked

const uint EVENT_OBJECT_TEXTSELECTIONCHANGED = 0x8014; // hwnd ID idChild is item w? test selection change

const uint EVENT_OBJECT_CONTENTSCROLLED = 0x8015;

const uint EVENT_SYSTEM_ARRANGMENTPREVIEW = 0x8016;

const uint EVENT_OBJECT_END = 0x80FF;

const uint EVENT_AIA_START = 0xA000;

const uint EVENT_AIA_END = 0xAFFF;

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.

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