Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

ScreenShot of "translucent", layered windows

Posted on 2002-05-17
12
Medium Priority
?
860 Views
Last Modified: 2011-09-20
ScreenShot of "translucent", layered windows

How can i get a screenshot including "translucent", layered windows like you can create with alphablending ??

I need a picture of the screen, including also the "translucent", layered windows, but i don't want to change the clipboard contents.

But creating a DC and using BitBlt() or WM_PRINT, works only with normal windows.

If possible in any way, i need a short code example.

PS:
I use Delphi 6 Enterp. and it has to work with it

Thank you for any answer.
0
Comment
Question by:Farderlorn
12 Comments
 
LVL 12

Expert Comment

by:Lee_Nover
ID: 7015945
interesting (listening :)
0
 
LVL 9

Expert Comment

by:ginsonic
ID: 7018108
You don't wish to simulate the "PrintScreen"-key press ?
0
 

Author Comment

by:Farderlorn
ID: 7019389
I need a picture of the screen, including also the "translucent", layered windows, but i don't want to change the clipboard contents.
0
Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 

Expert Comment

by:iddo_levin
ID: 7019798
I don't know how to do it, but you might save the clipboard content, simulate a PrintScreen key, and then reload the clipboard data saved earlier....

just a thaught
0
 

Author Comment

by:Farderlorn
ID: 7020202
Yes, that's possible, i thaught about it, too.
But it could slow down the machine, if you have a bigger amount of data in the clipboard, and you always have, if you use 1 or 2 office - products or special software, like we do.
0
 
LVL 1

Expert Comment

by:mgazza
ID: 7034610
heres a code to get a picture of the screen and it don't use the clipboard

procedure TForm1.createClick(Sender: TObject);
var
  DeskTopDC: HDc;
  DeskTopCanvas: TCanvas;
  DeskTopRect: TRect;
  Bitmap: TBitmap;
begin
  DeskTopDC := GetWindowDC(GetDeskTopWindow);
  DeskTopCanvas := TCanvas.Create;
  DeskTopCanvas.Handle := DeskTopDC;
  DeskTopRect := Rect(0,0,Screen.Width,Screen.Height);
  Bitmap := TBitmap.Create;
  with Bitmap do
  begin
    Width := Screen.Width;
    Height:= Screen.Height;
    PixelFormat := pfDevice;
  end;
  Bitmap.Canvas.CopyRect(DeskTopRect,DeskTopCanvas,DeskTopRect);
  image1.Picture.Bitmap:=bitmap;
  Bitmap.Free;
  DesktopCanvas.Free;
  ReleaseDC(GetDeskTopWindow,DeskTopDC);
 

end;
0
 

Author Comment

by:Farderlorn
ID: 7035044
This is a usually way to get a screenshot, but it does not include the "translucent", layered windows like you can create with alphablending.

You will get a screenshot, only including not "translucent" windows.

It is not possible to solve this problem with functions, you have used the last years. I could do it with a DC, like you did and then use BitBlt() with the const. CAPTUREBLT. But CAPTUREBLT does not works on my Delphi 6 Enterp., it seems not to be defined. And if i define it my self with (DWORD)0x40000000 i only get a black picture, no screenshot.

This is a hard question, and I would give 1000 points to it, but i have only 114.
0
 

Author Comment

by:Farderlorn
ID: 7038677
I got the solution from <Serhiy Perevoznyk>:


procedure ScreenShot(x : integer; y : integer; Width : integer; Height :
integer; bm : TBitMap);
const
  CAPTUREBLT = $40000000;
var
  dc: HDC; lpPal : PLOGPALETTE;
begin
{test width and height}
  if ((Width = 0) OR (Height = 0)) then exit;
  bm.Width := Width;
  bm.Height := Height;
{get the screen dc}
  dc := GetDc(0);
  if (dc = 0) then exit;
{do we have a palette device?}
  if (GetDeviceCaps(dc, RASTERCAPS) AND
  RC_PALETTE = RC_PALETTE) then
  begin
  {allocate memory for a logical palette}
  GetMem(lpPal, sizeof(TLOGPALETTE) + (255 * sizeof(TPALETTEENTRY)));
  {zero it out to be neat}
  FillChar(lpPal^, sizeof(TLOGPALETTE) + (255 * sizeof(TPALETTEENTRY)), #0);
  {fill in the palette version}
  lpPal^.palVersion := $300;
  {grab the system palette entries}
  lpPal^.palNumEntries :=
  GetSystemPaletteEntries(dc,0,256,lpPal^.palPalEntry);
  if (lpPal^.PalNumEntries <> 0) then
  begin
  {create the palette}
  bm.Palette := CreatePalette(lpPal^);
  end;
  FreeMem(lpPal, sizeof(TLOGPALETTE) + (255 * sizeof(TPALETTEENTRY)));
  end;
{copy from the screen to the bitmap}
BitBlt(bm.Canvas.Handle,0,0,Width,Height,Dc,x,y,SRCCOPY OR CAPTUREBLT);
{release the screen dc}
ReleaseDc(0, dc);
end;
0
 
LVL 3

Expert Comment

by:SteveWaite
ID: 7802436
it's 'SRCCOPY or CAPTUREBLT' that's important

DC := GetWindowDC(0);
try
  BitBlt(BackBuf.Canvas.Handle, 0, 0, BackBuf.Width, BackBuf.Height, DC, Cx, FCy, SRCCOPY or CAPTUREBLT);
finally
  ReleaseDC(0, DC);
end;


Regards,
Steve
0
 
LVL 3

Expert Comment

by:SteveWaite
ID: 7802447
as in:
const
  CAPTUREBLT = $40000000;

above
0
 
LVL 1

Expert Comment

by:pnh73
ID: 9005901
No comment has been added lately, so it's time to clean up this TA.
I will leave a recommendation in the Cleanup topic area that this question is:

PAQ with refund

Please leave any comments here within the next seven days.
 
PLEASE DO NOT ACCEPT THIS COMMENT AS AN ANSWER!
 
Paul (pnh73)
EE Cleanup Volunteer
0
 

Accepted Solution

by:
YensidMod earned 0 total points
ID: 9096797
Question is PAQ'd and points refunded.

YensidMod
Community Support Moderator @Experts Exchange
0

Featured Post

New feature and membership benefit!

New feature! Upgrade and increase expert visibility of your issues with Priority Questions.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

A lot of questions regard threads in Delphi.   One of the more specific questions is how to show progress of the thread.   Updating a progressbar from inside a thread is a mistake. A solution to this would be to send a synchronized message to the…
Introduction Raise your hands if you were as upset with FireMonkey as I was when I discovered that there was no TListview.  I use TListView in almost all of my applications I've written, and I was not going to compromise by resorting to TStringGrid…
Are you ready to place your question in front of subject-matter experts for more timely responses? With the release of Priority Question, Premium Members, Team Accounts and Qualified Experts can now identify the emergent level of their issue, signal…
Despite its rising prevalence in the business world, "the cloud" is still misunderstood. Some companies still believe common misconceptions about lack of security in cloud solutions and many misuses of cloud storage options still occur every day. …
Suggested Courses

886 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question