WinAPI Shim Reference

This page lists the Win32 APIs available through XPF's shim layer. These shims exist to support third-party WPF controls on non-Windows platforms. They are not a general-purpose Win32 emulation layer.

For setup and configuration, see Win32 API Shims.

note

"Shimmed" means XPF intercepts the call and provides a cross-platform implementation. The behavior may not be identical to native Win32 in all cases. Functions marked with (W) have both ANSI and Unicode variants available.

user32.dll

Window creation and lifecycle

Function	Description
CreateWindowEx (W)	Creates a window with extended styles. Returns a virtual HWND managed by XPF.
RegisterClass	Registers a window class.
RegisterClassExW	Registers a window class (extended).
DestroyWindow	Destroys a window created with CreateWindowEx.

Window properties and state

Function	Description
GetWindowRect	Gets the window bounding rectangle in screen coordinates.
GetClientRect	Gets the client area rectangle.
GetWindowPlacement	Gets the show state and positions of a window.
GetWindowInfo	Gets window information including styles and borders.
IsWindow	Tests whether a handle is a valid window.
IsWindowEnabled	Tests whether a window accepts user input.
IsWindowVisible	Tests whether a window is visible.
GetWindowLong / SetWindowLong	Gets or sets a 32-bit value in the window data.
GetWindowLongPtr (W) / SetWindowLongPtr	Gets or sets a pointer-sized value in the window data. Used for window styles and procedures.

Window position and layout

Function	Description
SetWindowPos	Sets the size, position, and Z-order of a window.
AdjustWindowRectEx	Calculates the required window size for a given client area size.
BeginDeferWindowPos / EndDeferWindowPos	Batches multiple window position changes for performance.

Window hierarchy

Function	Description
GetActiveWindow	Returns the active window on the calling thread.
GetTopWindow	Returns the topmost child window.
GetWindow	Retrieves a related window (next, previous, owner, child).
GetDesktopWindow	Returns a handle to the desktop window.
FindWindow	Finds a top-level window by class name or title.
WindowFromPoint	Returns the window at a given screen coordinate.
EnumChildWindows	Enumerates child windows of a parent.
EnumThreadWindows	Enumerates windows owned by a thread.

Window display

Function	Description
SetWindowRgn	Sets a window's visible region.
RedrawWindow	Redraws a window or region.
InvalidateRect	Marks a rectangle as needing repaint.
SetWindowDisplayAffinity	Controls whether a window can be captured by screen capture tools. Stub implementation.

System menu

Function	Description
GetSystemMenu	Returns a handle to the window's system menu (the menu shown when clicking the window icon).

Focus and input

Function	Description
GetFocus	Returns the window with keyboard focus.
SetForegroundWindow	Brings a window to the foreground and gives it focus.
GetCapture / ReleaseCapture	Gets or releases mouse capture.
GetKeyState	Returns the state of a virtual key (up, down, toggled).
GetCursorPos	Returns the cursor position in screen coordinates.
GetMessagePos / GetMessageTime	Returns the cursor position and time of the last message.

Messages

Function	Description
SendMessage	Sends a message to a window and waits for processing. Limited message support.
PostMessage	Posts a message to a window's message queue. Limited message support.
DefWindowProc (W)	Provides default processing for messages not handled by a window procedure.
FormatMessageW	Formats a system error message string.

Hooks

Function	Description
SetWindowsHookEx	Installs a hook procedure. Limited hook types supported.
UnhookWindowsHookEx	Removes a hook procedure.

Caret

Function	Description
CreateCaret	Creates a caret (text cursor) for a window.
ShowCaret / HideCaret	Shows or hides the caret.
DestroyCaret	Destroys the current caret.
SetCaretPos	Sets the caret position.

Menus

Function	Description
TrackPopupMenuEx	Displays a shortcut menu at a specified location.
EnableMenuItem	Enables, disables, or grays a menu item.

System information

Function	Description
GetSysColor	Returns the current color of a display element (button face, window background, etc.).
SystemParametersInfo (W)	Gets or sets system-wide parameters (scroll bar size, animation settings, etc.).
GetDoubleClickTime	Returns the maximum interval between two clicks for a double-click.
GetSystemMetrics	Returns system metric values (screen size, icon size, scroll bar dimensions, etc.).
GetCaretBlinkTime	Returns the caret blink interval.

Clipboard

Function	Description
AddClipboardFormatListener	Registers a window to receive clipboard change notifications.

gdi32.dll

Device contexts

Function	Description
GetDC / ReleaseDC	Gets or releases a device context for a window.
CreateCompatibleDC / DeleteDC	Creates or deletes a memory device context.
GetDeviceCaps	Returns device capabilities (DPI, color depth, etc.).

Drawing objects

Function	Description
CreateRectRgn	Creates a rectangular region.
CreateRoundRectRgn	Creates a rectangular region with rounded corners.
CreateRectRgnIndirect	Creates a rectangular region from a RECT structure.
DeleteObject	Deletes a GDI object (region, brush, pen, etc.).
GetStockObject	Returns a handle to a predefined stock object.

Coordinate mapping

Function	Description
GetMapMode / SetMapMode	Gets or sets the mapping mode for a device context.
SetWindowExtEx / SetViewportExtEx	Sets the window or viewport extents for coordinate mapping.
OffsetRect	Moves a rectangle by a specified offset.

dwmapi.dll

Function	Description
DwmIsCompositionEnabled	Returns whether desktop composition is enabled. Always returns true on non-Windows.
DwmExtendFrameIntoClientArea	Extends the window frame into the client area.
DwmGetWindowAttribute	Gets a DWM window attribute. Limited attribute support.
DwmSetWindowAttribute	Sets a DWM window attribute. Limited attribute support.

shcore.dll / Monitor APIs

Function	Description
MonitorFromPoint	Returns the monitor containing a point.
MonitorFromRect	Returns the monitor with the largest intersection with a rectangle.
MonitorFromWindow	Returns the monitor containing the largest part of a window.
GetMonitorInfo	Returns the display area and work area of a monitor.
EnumDisplayMonitors	Enumerates display monitors.
GetDpiForMonitor	Returns the DPI of a monitor.
GetDpiForWindow	Returns the DPI for a window.
GetProcessDpiAwareness	Returns the DPI awareness setting for a process.

imm32.dll (Input Method Editor)

Function	Description
ImmCreateContext / ImmDestroyContext	Creates or destroys an IME input context.
ImmGetContext / ImmReleaseContext	Gets or releases the IME context for a window.
ImmAssociateContext	Associates an IME context with a window.
ImmSetOpenStatus / ImmGetOpenStatus	Opens or closes the IME, or queries the current state.
ImmNotifyIME	Sends a notification to the IME.
ImmGetProperty	Returns IME properties.
ImmGetCompositionString (W)	Returns the composition string (the text being composed).
ImmSetCompositionFont (W)	Sets the font used to display the composition string.
ImmConfigureIMEW	Opens the IME configuration dialog.
ImmSetCompositionWindow	Sets the position of the composition window.
ImmSetCandidateWindow	Sets the position of the candidate list window.
ImmGetDefaultIMEWnd	Returns the default IME window handle.

kernel32.dll

Function	Description
GetCurrentThreadId	Returns the calling thread's ID.
GetModuleFileName	Returns the full path of a loaded module.
GetModuleHandle (W)	Returns the handle of a loaded module by name.
LoadLibrary (W)	Loads a DLL. Intercepted by the shim to redirect Win32 DLL loads.
LoadString (W)	Loads a string resource from an executable.
CloseHandle	Closes an object handle.
RtlGetVersion	Returns the OS version. Returns emulated Windows version info on non-Windows.

File and memory mapping

Function	Description
CreateFileMapping	Creates or opens a file mapping object.
MapViewOfFile / UnmapViewOfFile	Maps or unmaps a view of a file mapping into the process address space.
FindFirstFile / FindNextFile / FindClose	Enumerates files in a directory.

Memory

Function	Description
RtlMoveMemory	Copies a block of memory.

shell32.dll

Function	Description
SHGetFileInfo (W)	Returns information about a file (icon, display name, type).
ExtractIconEx (W)	Extracts icons from an executable or DLL.

uxtheme.dll

Function	Description
IsThemeActive	Returns whether visual styles are active.
SetWindowThemeAttribute	Sets theme attributes on a window.

msctf.dll

Function	Description
TF_CreateThreadMgr	Creates a Text Services Framework thread manager.