Debenu - QuickPDF - "The device context handle" question

[mLipok]

I would ask for an indication of what is "The device context handle" in AutoIt.

 

Below a handful of knowledge and examples, which, unfortunately, not quite speak to me (which is why I ask for help in clarifying their meaning).

 

http://www.debenu.com/docs/pdf_library_reference/RenderPageToDC.php

 This function renders a page from the selected document directly onto a graphics surface.

On Windows the target surface is a Device Context handle (DC).

 

 

and C++ example:

http://www.quickpdflibrary.com/faq/can-i-use-quick-pdf-as-a-viewer-in-my-c-application.php

HWND m_hwnd = HWND(GDK_WINDOW_HWND(this->m_drawingArea.get_window()>gobj() ));
HDC m_hdc = GetDC(m_hwnd);   
QP.RenderPageToDC(100, 1,(int)(HDC) m_hdc);

[Danp2]

_WinAPI_GetDC

[mLipok]

Thanks

[mLipok]

I have additional questions.
There is a small problem with the refresh of the window.

Just minimize the window and restore it to its previous size and as a result I do not see already rendered image.
Anyone knows the solution?
Please send me only indicate the direction of a solution to this problem.

 

Here is my code.

expandcollapse popup

#include <WinAPI.au3>
#include <GUIConstantsEx.au3>
#include <WindowsConstants.au3>
#include <MsgBoxConstants.au3>
#include "QuickPDF.au3"


_QPDF_SetLicenseKey('ENTER YOUR KEY HERE')

; using own COM Error Handling
_QPDF_UseErrorHandler()

_QP_PDFFileInGUI(@ScriptDir & "\Example_HelloWorld.pdf", 70, 0, 612, 792)

Func _QP_PDFFileInGUI($sFileName, $iLeft, $iTop, $iWidth, $iHeight, $iSelectPage = 1)
    ; http://www.quickpdflibrary.com/faq/drawing-into-dc-scaling-problem.php

    ; Display GUI.
    Local $hwnd = GUICreate($sFileName, $iWidth, $iHeight, $iLeft, $iTop)
    GUISetState(@SW_SHOW)
    
    ; get Device context handle
    Local $hDC = _WinAPI_GetDC($hwnd)

    ; Object initialization
    Local $oQP
    If _QPDF_CreateObjectAndUnlock($oQP) = 1 Then
        ; get Device Context
        ; Load PDF File to QP Object
        $oQP.LoadFromFile($sFileName, '');
        ; select Page
        $oQP.SelectPage($iSelectPage);
        ; calculate DPI
        Local $iPageWidth = $oQP.PageWidth();
        Local $iInches = $iPageWidth / 72
        Local $iDisplayDPI = $iWidth / $iInches
        ; render QP object to Device Context
        $oQP.RenderPageToDC($iDisplayDPI, 12, $hDC);
    EndIf

    ; Loop until the user exits.
    While 1
        Switch GUIGetMsg()
            Case $GUI_EVENT_CLOSE
                ExitLoop
        EndSwitch
    WEnd
    
    _WinAPI_ReleaseDC($hwnd, $hDC)
    $oQP = 0 ; CleanUp - destroy object
    GUIDelete($hwnd) ; Deletes a GUI window and all controls that it contains.

EndFunc   ;==>_QP_PDFFileInGUI

#include "QuickPDF.au3" can be downloaded from here.

[mLipok]

Last attempt to call for help before suicide attempt.

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kidding

but maybe someone knows the answer?

The question is not necessarily related to the Debenu.
More generally, the issues relates to refresh Window and the Device Context.

 

mLipok

[mLipok]

I tried to cope with the described problem, but I have not found a solution.

Here are two examples of the window.
Left - screenshot made ​​after starting the script - the window that appears, DC correctly.
Rights - screenshot made ​​when you drag another window over the DC window.

 

Again, please help.

mLipok