Capturas usando a API de ampliação: SetThreadDesktop falha quando alterna para uma nova área de trabalho
Tenho o seguinte código delphi (espelhado emist Exemplo C ++) capaz de tirar screenshots usandoMagnification
api ..
O código funciona bem quando está capturando a área de trabalho "padrão", mas também preciso capturar uma nova área de trabalho ativa e, quando alterno para uma nova área de trabalho, o código falha nesta linha referente aSetThreadDesktop
:
if (not SetThreadDesktop(HNewDesk)) then
begin
Writeln('SetThreadDesktop Failed.');
Exit;
end;
Sei que não posso ligar paraSeThreadDesktop
dentro de um thread que já criou uma janela (neste caso, essa janela parece ser referente aMagnification
API).
Como posso resolver isso?
Aqui está o código completo:
program Project2;
{$APPTYPE CONSOLE}
{$R *.res}
uses
Windows,
Classes,
Graphics,
SysUtils,
Magnification;
var
MyBMP: TBitmap;
abitmap: HBitmap;
desktoprect: TRect;
hWndMag: HWND;
CallbackDone: Boolean;
function MagImageScalingCallback(HWND: HWND; srcdata: Pointer;
srcheader: MAGIMAGEHEADER; destdata: Pointer; destheader: MAGIMAGEHEADER;
unclipped: TRect; clipped: TRect; dirty: HRGN): BOOL; stdcall;
var
lpbmih: TBitmapInfoHeader;
lpbmi: TBitmapInfo;
ADC: HDC;
begin
ADC := GetWindowDC(HWND);
Fillchar(lpbmih, SizeOf(lpbmih), 0);
lpbmih.biSize := SizeOf(lpbmih);
lpbmih.biHeight := -srcheader.Height;
lpbmih.biWidth := srcheader.Width;
lpbmih.biSizeImage := srcheader.cbSize;
lpbmih.biPlanes := 1;
lpbmih.biBitCount := 32;
lpbmih.biCompression := BI_RGB;
Fillchar(lpbmi, SizeOf(lpbmi), 0);
lpbmi.bmiHeader.biSize := SizeOf(lpbmi.bmiHeader);
lpbmi.bmiHeader.biHeight := -srcheader.Height;
lpbmi.bmiHeader.biWidth := srcheader.Width;
lpbmi.bmiHeader.biSizeImage := srcheader.cbSize;
lpbmi.bmiHeader.biPlanes := 1;
lpbmi.bmiHeader.biBitCount := 32;
lpbmi.bmiHeader.biCompression := BI_RGB;
MyBMP := TBitmap.Create;
abitmap := 0;
try
abitmap := CreateDIBitmap(ADC, lpbmih, CBM_INIT, srcdata, lpbmi,
DIB_RGB_COLORS);
MyBMP.Handle := abitmap;
CallbackDone := True;
finally
DeleteDC(ADC);
end;
Result := True;
end;
function HostWndProc(hWindow: HWND; Msg: UINT; wParam: wParam; lParam: lParam)
: LRESULT; stdcall;
begin
Result := DefWindowProc(hWindow, Msg, wParam, lParam);
end;
procedure ConfigMag;
const
HOST_CLASSNAME = 'MagnifierHost';
var
wc: TWndClass;
hWndHost, desktop: HWND;
begin
hWndHost := 0;
wc.lpszClassName := HOST_CLASSNAME;
wc.lpfnWndProc := @HostWndProc;
wc.Style := 0;
wc.hInstance := 0;
wc.hIcon := 0;
wc.hCursor := 0;
wc.hbrBackground := 0;
wc.lpszMenuName := nil;
wc.cbClsExtra := 0;
wc.cbWndExtra := 0;
desktop := GetDesktopWindow;
GetWindowRect(desktop, desktoprect);
if (Windows.RegisterClass(wc) <> 0) then
hWndHost := CreateWindowEx(WS_EX_TOPMOST Or WS_EX_LAYERED or
WS_EX_TRANSPARENT, PChar(HOST_CLASSNAME), 'Host Window',
WS_POPUP or WS_CLIPCHILDREN, 0, 0, desktoprect.Width, desktoprect.Height,
0, 0, GetModuleHandle(0), nil);
if (hWndHost <> 0) then
begin
SetWindowPos(hWndHost, 0, 0, 0, desktoprect.Width, desktoprect.Height,
SWP_HIDEWINDOW);
SetLayeredWindowAttributes(hWndHost, 0, 255, LWA_ALPHA);
end;
If (MagInitialize) Then
hWndMag := CreateWindowEx(0, WC_MAGNIFIER, 'MagnifierWindow',
WS_CHILD or MS_SHOWMAGNIFIEDCURSOR or WS_VISIBLE, 0, 0, desktoprect.Width,
desktoprect.Height, hWndHost, 0, 0, nil);
If (hWndMag = 0) Then
Exit;
if (MagSetImageScalingCallback(hWndMag, MagImageScalingCallback)) then;
end;
procedure xGetScreenToBmp(index: Integer);
var
filterList: THWNDArray;
sourceRect: TRect;
begin
{ filterList[0] := Form1.Handle;
If (MagSetWindowFilterList(hWndMag, MW_FILTERMODE_EXCLUDE, 1,
@filterList[0])) Then; }
sourceRect.Left := 0;
sourceRect.Top := 0;
sourceRect.Right := desktoprect.Width;
sourceRect.Bottom := desktoprect.Height;
CallbackDone := False;
If (MagSetWindowSource(hWndMag, sourceRect)) Then;
repeat
Writeln('loop');
until CallbackDone;
MyBMP.PixelFormat := pf24bit;
MyBMP.SaveToFile('c:\capture\' + InttoStr(index) + '.bmp');
DeleteObject(abitmap);
MyBMP.Free;
end;
function SelectHDESK(HNewDesk: HDESK): Boolean; stdcall;
var
HOldDesk: HDESK;
dwDummy: DWORD;
sName: array [0 .. 255] of Char;
hThreadID: THandle;
ThreadID: DWORD;
begin
Result := False;
HOldDesk := GetThreadDesktop(GetCurrentThreadId);
if (not GetUserObjectInformation(HNewDesk, UOI_NAME, @sName[0], 256, dwDummy))
then
begin
Writeln('GetUserObjectInformation Failed.');
Exit;
end;
if (not SetThreadDesktop(HNewDesk)) then
begin
Writeln('SetThreadDesktop Failed.');
Exit;
end;
if (not CloseDesktop(HOldDesk)) then
begin
Writeln('CloseDesktop Failed.');
Exit;
end;
Result := True;
end;
function SelectDesktop(pName: PChar): Boolean; stdcall;
var
HDesktop: HDESK;
begin
Result := False;
if Assigned(pName) then
HDesktop := OpenDesktop(pName, 0, False, DESKTOP_CREATEMENU or
DESKTOP_CREATEWINDOW or DESKTOP_ENUMERATE or DESKTOP_HOOKCONTROL or
DESKTOP_WRITEOBJECTS or DESKTOP_READOBJECTS or DESKTOP_SWITCHDESKTOP or
GENERIC_WRITE)
else
HDesktop := OpenInputDesktop(0, False, DESKTOP_CREATEMENU or
DESKTOP_CREATEWINDOW or DESKTOP_ENUMERATE or DESKTOP_HOOKCONTROL or
DESKTOP_WRITEOBJECTS or DESKTOP_READOBJECTS or DESKTOP_SWITCHDESKTOP or
GENERIC_WRITE);
if (HDesktop = 0) then
begin
OutputDebugString(PChar('Get Desktop Failed: ' + InttoStr(GetLastError)));
Exit;
end;
Result := SelectHDESK(HDesktop);
end;
function InputDesktopSelected: Boolean; stdcall;
var
HThdDesk: HDESK;
HInpDesk: HDESK;
dwError: DWORD;
dwDummy: DWORD;
sThdName: array [0 .. 255] of Char;
sInpName: array [0 .. 255] of Char;
begin
Result := False;
HThdDesk := GetThreadDesktop(GetCurrentThreadId);
HInpDesk := OpenInputDesktop(0, False, DESKTOP_CREATEMENU or
DESKTOP_CREATEWINDOW or DESKTOP_ENUMERATE or DESKTOP_HOOKCONTROL or
DESKTOP_WRITEOBJECTS or DESKTOP_READOBJECTS or DESKTOP_SWITCHDESKTOP);
if (HInpDesk = 0) then
begin
Writeln('OpenInputDesktop Failed.');
dwError := GetLastError;
Result := (dwError = 170);
Exit;
end;
if (not GetUserObjectInformation(HThdDesk, UOI_NAME, @sThdName[0], 256,
dwDummy)) then
begin
Writeln('GetUserObjectInformation HThdDesk Failed.');
CloseDesktop(HInpDesk);
Exit;
end;
if (not GetUserObjectInformation(HInpDesk, UOI_NAME, @sInpName[0], 256,
dwDummy)) then
begin
Writeln('GetUserObjectInformation HInpDesk Failed.');
CloseDesktop(HInpDesk);
Exit;
end;
CloseDesktop(HInpDesk);
Result := (lstrcmp(sThdName, sInpName) = 0);
end;
var
idx: Integer;
begin
try
ConfigMag;
while True do
begin
if InputDesktopSelected then
xGetScreenToBmp(idx)
else if SelectDesktop(nil) then
xGetScreenToBmp(idx);
Sleep(3000);
Inc(idx);
end;
except
on E: Exception do
Writeln(E.ClassName, ': ', E.Message);
end;
Readln;
end.
Magnification.pas
unit Magnification;
{$ALIGN ON}
{$MINENUMSIZE 4}
interface
uses
Windows;
const
// Magnifier Class Name
WC_MAGNIFIERA: AnsiString = 'Magnifier';
WC_MAGNIFIERW: WideString = 'Magnifier';
WC_MAGNIFIER = 'Magnifier';
// Magnifier Window Styles
MS_SHOWMAGNIFIEDCURSOR = $0001;
MS_CLIPAROUNDCURSOR = $0002;
MS_INVERTCOLORS = $0004;
// Filter Modes
MW_FILTERMODE_EXCLUDE = 0;
MW_FILTERMODE_INCLUDE = 1;
type
tagMAGTRANSFORM = record
v: array[1..3, 1..3] of Single;
end;
MAGTRANSFORM = tagMAGTRANSFORM;
TMagTransform = tagMAGTRANSFORM;
PMagTransform = ^TMagTransform;
tagMAGIMAGEHEADER = record
width: UINT;
height: UINT;
format: TGUID;
stride: UINT;
offset: UINT;
cbSize: UINT;
end;
MAGIMAGEHEADER = tagMAGIMAGEHEADER;
TMagImageHeader = tagMAGIMAGEHEADER;
PMagImageHeader = ^TMagImageHeader;
tagMAGCOLOREFFECT = record
transform: array[1..5, 1..5] of Single;
end;
MAGCOLOREFFECT = tagMAGCOLOREFFECT;
TMagColorEffect = tagMAGCOLOREFFECT;
PMagColorEffect = ^TMagColorEffect;
TMagImageScalingCallback = function (hwnd: HWND; srcdata: Pointer;
srcheader: MAGIMAGEHEADER; destdata: Pointer; destheader: MAGIMAGEHEADER;
unclipped: TRect; clipped: TRect; dirty: HRGN): BOOL; stdcall;
THWNDArray = array[0..0] of HWND;
PHWNDArray = ^THWNDArray;
// Public Functions
function MagInitialize(): BOOL; stdcall;
function MagUninitialize(): BOOL; stdcall;
function MagSetWindowSource(hwnd: HWND; rect: TRect): BOOL; stdcall;
function MagGetWindowSource(hwnd: HWND; var Rect: TRect): BOOL; stdcall;
function MagSetWindowTransform(hwnd: HWND; var Transform: TMagTransform): BOOL; stdcall;
function MagGetWindowTransform(hwnd: HWND; var Transform: TMagTransform): BOOL; stdcall;
function MagSetWindowFilterList(hwnd: HWND; dwFilterMode: DWORD;
count: Integer; pHWND: PHWNDArray): BOOL; stdcall;
function MagGetWindowFilterList(hwnd: HWND; var dwFilterMode: DWORD;
count: Integer; pHWND: PHWNDArray): Integer; stdcall;
function MagSetImageScalingCallback(hwnd: HWND;
MagImageScalingCallback: TMagImageScalingCallback): BOOL; stdcall;
// MagImageScalingCallback WINAPI MagGetImageScalingCallback(HWND hwnd );
function MagSetColorEffect(hwnd: HWND; var Effect: TMagColorEffect): BOOL; stdcall;
function MagGetColorEffect(hwnd: HWND; var Effect: TMagColorEffect): BOOL; stdcall;
implementation
const
MagnificationDll = 'Magnification.dll';
function MagInitialize; external MagnificationDll name 'MagInitialize';
function MagUninitialize; external MagnificationDll name 'MagUninitialize';
function MagSetWindowSource; external MagnificationDll name 'MagSetWindowSource';
function MagGetWindowSource; external MagnificationDll name 'MagGetWindowSource';
function MagSetWindowTransform; external MagnificationDll name 'MagSetWindowTransform';
function MagGetWindowTransform; external MagnificationDll name 'MagGetWindowTransform';
function MagSetWindowFilterList; external MagnificationDll name 'MagSetWindowFilterList';
function MagGetWindowFilterList; external MagnificationDll name 'MagGetWindowFilterList';
function MagSetImageScalingCallback; external MagnificationDll name 'MagSetImageScalingCallback';
function MagSetColorEffect; external MagnificationDll name 'MagSetColorEffect';
function MagGetColorEffect; external MagnificationDll name 'MagGetColorEffect';
end.