Prepares the specified window for painting
#include <WinAPIGdi.au3>
_WinAPI_BeginPaint ( $hWnd, ByRef $tPAINTSTRUCT )
| $hWnd | Handle to the window to be repainted. |
| $tPAINTSTRUCT | $tagPAINTSTRUCT structure that will receive painting information. When the function call, this parameter should be any valid variable, the function creates this structure itself. |
| Success: | Handle to a display device context for the specified window. |
| Failure: | 0, call _WinAPI_GetLastError() to get extended error information. |
This function automatically sets the clipping region of the device context to exclude any area outside the update region.
The update region is set by the _WinAPI_InvalidateRect() or _WinAPI_InvalidateRgn() function and by the system after sizing, moving, creating, scrolling, or any other operation that affects the client area.
If the update region is marked for erasing, _WinAPI_BeginPaint() sends a WM_ERASEBKGND message to the window.
An application should not call _WinAPI_BeginPaint() except in response to a WM_PAINT message.
Each call to _WinAPI_BeginPaint() must have a corresponding call to the _WinAPI_EndPaint() function.
_WinAPI_InvalidateRect, _WinAPI_InvalidateRgn
Search BeginPaint in MSDN Library.
#include <GUIConstantsEx.au3>
#include <SendMessage.au3>
#include <StaticConstants.au3>
#include <WinAPIGdi.au3>
#include <WinAPIGdiDC.au3>
#include <WinAPIHObj.au3>
#include <WinAPIShellEx.au3>
#include <WinAPISysWin.au3>
#include <WindowsConstants.au3>
Opt('MouseCoordMode', 2)
Global $g_iCount = 0
OnAutoItExitRegister('OnAutoItExit')
; Create GUI
Local $hForm = GUICreate('Test ' & StringReplace(@ScriptName, '.au3', '()'), 400, 400)
Local $idPic = GUICtrlCreatePic('', 0, 0, 400, 400)
GUICtrlSetCursor(-1, 0)
Local $hPic = GUICtrlGetHandle($idPic)
Local $idLabel = GUICtrlCreateLabel('', 176, 176, 48, 48)
GUICtrlSetBkColor(-1, $GUI_BKCOLOR_TRANSPARENT)
Global $g_hLabel = GUICtrlGetHandle($idLabel)
; Extract icon
Local $hIcon = _WinAPI_ShellExtractIcon(@SystemDir & '\shell32.dll', 130, 48, 48)
; Register label window proc
Global $g_hDll = DllCallbackRegister('_WinProc', 'ptr', 'hwnd;uint;wparam;lparam')
Local $pDll = DllCallbackGetPtr($g_hDll)
Global $g_hProc = _WinAPI_SetWindowLong($g_hLabel, $GWL_WNDPROC, $pDll)
; Create gradient
Local $hDC = _WinAPI_GetDC($hPic)
Local $hDestDC = _WinAPI_CreateCompatibleDC($hDC)
Local $hBitmap = _WinAPI_CreateCompatibleBitmap($hDC, 400, 400)
Local $hDestSv = _WinAPI_SelectObject($hDestDC, $hBitmap)
Local $aVertex[2][3] = [[0, 0, 0xAA00FF], [400, 400, 0x33004D]]
_WinAPI_GradientFill($hDestDC, $aVertex)
_WinAPI_ReleaseDC($hPic, $hDC)
_WinAPI_SelectObject($hDestDC, $hDestSv)
_WinAPI_DeleteDC($hDestDC)
; Set gradient to control
_SendMessage($hPic, $STM_SETIMAGE, 0, $hBitmap)
Local $hObj = _SendMessage($hPic, $STM_GETIMAGE)
If $hObj <> $hBitmap Then
_WinAPI_DeleteObject($hBitmap)
EndIf
GUISetState(@SW_SHOW)
Local $aPos
While 1
Switch GUIGetMsg()
Case $GUI_EVENT_CLOSE
ExitLoop
Case $GUI_EVENT_PRIMARYDOWN
$aPos = MouseGetPos()
If _WinAPI_PtInRectEx($aPos[0], $aPos[1], 0, 0, 400, 400) Then
GUICtrlSetPos($idLabel, $aPos[0] - 24, $aPos[1] - 24)
EndIf
EndSwitch
WEnd
Func _WinProc($hWnd, $iMsg, $wParam, $lParam)
Switch $iMsg
Case $WM_PAINT
If $g_iCount = 0 Then
Local $tPAINTSTRUCT, $hDC
$g_iCount += 1
$hDC = _WinAPI_BeginPaint($hWnd, $tPAINTSTRUCT)
_WinAPI_DrawIconEx($hDC, 0, 0, $hIcon, 48, 48)
_WinAPI_EndPaint($hWnd, $tPAINTSTRUCT)
$g_iCount -= 1
Return 0
EndIf
EndSwitch
Return _WinAPI_CallWindowProc($g_hProc, $hWnd, $iMsg, $wParam, $lParam)
EndFunc ;==>_WinProc
Func OnAutoItExit()
_WinAPI_SetWindowLong($g_hLabel, $GWL_WNDPROC, $g_hProc)
DllCallbackFree($g_hDll)
EndFunc ;==>OnAutoItExit