ScreenToClient

The ScreenToClient function converts the screen coordinates of a specified point on the screen to client coordinates.

BOOL ScreenToClient(
  HWND hWnd,        // window handle for source coordinates
  LPPOINT lpPoint   // address of structure containing coordinates
);
 

Parameters

hWnd

Handle to the window whose client area will be used for the conversion.

lpPoint

Pointer to a POINT structure that contains the screen coordinates to be converted.

Return Values

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero.

Windows NT: To get extended error information, call GetLastError.

Remarks

The function uses the window identified by the hWnd parameter and the screen coordinates given in the POINT structure to compute client coordinates. It then replaces the screen coordinates with the client coordinates. The new coordinates are relative to the upper-left corner of the specified window's client area.

The ScreenToClient function assumes the specified point is in screen coordinates.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Requires version 1.0 or later.
  Header: Declared in winuser.h.
  Import Library: Use user32.lib.

See Also

Coordinate Spaces and Transformations Overview, Coordinate Space and Transformation Functions, ClientToScreen, MapWindowPoints, POINT