GweBypassCoredllThunk_t::GetUpdateRect_I (Windows Embedded CE 6.0)

1/6/2010

This method retrieves the coordinates of the smallest rectangle that completely encloses the update region of the specified window in client coordinates. If the window does not have an update region, GweBypassCoredllThunk_t::GetUpdateRect_I retrieves an empty rectangle, and sets all coordinates to zero.

Syntax

static BOOL WINAPI GetUpdateRect_I(
  HWND hwndThis,
  LPRECT lpRect,
  BOOL bErase
);

Parameters

• hwndThis
  [in] Handle to the window with an update region that is to be retrieved.

• lpRect
  [out] Long pointer to the RECT structure that receives the coordinates of the enclosing rectangle.

  An application can set this parameter to NULL to determine whether an update region exists for the window. If this parameter is NULL, GweBypassCoredllThunk_t::GetUpdateRect_I returns nonzero if an update region exists, and zero if one does not. This value provides a simple and efficient means of determining whether a WM_PAINTmessage resulted from an invalid area.

• bErase
  [in] Boolean that specifies whether the background in the update region is to be erased. If this parameter is TRUE and the update region is not empty, GweBypassCoredllThunk_t::GetUpdateRect_I sends a WM_ERASEBKGND message to the specified window to erase the background.

Return Value

Nonzero indicates that the update region is not empty. Zero indicates that there is no update region. To get extended error information, call GetLastError.

Remarks

This method is an internal version of the GetUpdateRect function.

The update rectangle retrieved by the GweBypassCoredllThunk_t::BeginPaint_I method is identical to that retrieved by GweBypassCoredllThunk_t::GetUpdateRect_I.

GweBypassCoredllThunk_t::BeginPaint_I automatically validates the update region, so any call to GweBypassCoredllThunk_t::GetUpdateRect_I made immediately after the call to GweBypassCoredllThunk_t::BeginPaint_I retrieves an empty update region.

Requirements

See Also

Reference

GweBypassCoredllThunk_t
GetUpdateRect
GweBypassCoredllThunk_t::BeginPaint_I
GweBypassCoredllThunk_t::GetUpdateRgn_I
GweBypassCoredllThunk_t::InvalidateRect_I
GweBypassCoredllThunk_t::UpdateWindow_I
GweBypassCoredllThunk_t::ValidateRect_I
RECT