Taking screenshot behind the form using magnification

[Zacherl]

Zitat von victorlus:

My goal is to be able to capture what's behind the form, which works on win7, win8, win10, if it's very difficult I can pay to do it for myself.

Yeah I understood that, but WHY do you want to do that?

[victorlus]

Zitat von Zacherl:

Zitat von victorlus:

My goal is to be able to capture what's behind the form, which works on win7, win8, win10, if it's very difficult I can pay to do it for myself.

Yeah I understood that, but WHY do you want to do that?

I need to do this, to monitor what's behind the form
My program will work this way, visible to the client all time, I can see what is behind the form

[Zacherl]

Zitat von victorlus:

Zitat von Zacherl:

Zitat von victorlus:

My goal is to be able to capture what's behind the form, which works on win7, win8, win10, if it's very difficult I can pay to do it for myself.

Yeah I understood that, but WHY do you want to do that?

I need to do this, to monitor what's behind the form
My program will work this way, visible to the client all time, I can see what is behind the form

Mhh sorry, I guess I cant help you with that. Not sure whats the purpose of such a program. You could use PrintWindow for specific windows (you might even be able to compose your own "desktop" by iterating through all visible windows). This should work for background windows, but might not work for minimized ones.

[EWeiss]

Zitat:

This should work for background windows, but might not work for minimized ones.

NO that not work.

Zitat:

The PrintWindow function copies a visual window into the specified device context (DC), typically a printer DC.

The Desktop is not a real Window.
And PrintWindow works only for the own Window (or within active Desktop), you can not capture the Background from Desktop that Fails.

and i have tell forget it without minimize, or hide your Form.

nobody can help for that.
but here is what you can see behind the form.

greets

[HolgerX]

Hm..

1.) It is possible to make a ScreenShot without the foreground Application!

2.) The DESKTOP is a Window! It is the Mainwindow of an 'Explorer' instanz, in older Windowsversions 'Progman'!

I made a small demo, where i use PrintWindow!
(Test_ScreenShot_BackGround.zip)
It is made with Delphi 6 and goes to all Apps in Z-Order, starting with the last (Desktop!).

I have tested it in Windows8.1 (Classic Shell).

[EWeiss]

Zitat von HolgerX:

Hm..

1.) It is possible to make a ScreenShot without the foreground Application!

2.) The DESKTOP is a Window! It is the Mainwindow of an 'Explorer' instanz, in older Windowsversions 'Progman'!

I made a small demo, where i use PrintWindow!
(Test_ScreenShot_BackGround.zip)
It is made with Delphi 6 and goes to all Apps in Z-Order, starting with the last (Desktop!).

I have tested it in Windows8.1 (Classic Shell).

Zitat:

It is possible to make a ScreenShot

and your think that is a sreenshot? sorry for me that is nothing
and Fails on W7 Forget it (40% Cpu? )
you should handle WM_PRINT and WM_PRINTCLIENT. (i think you do nothing of both)

Zitat:

The DESKTOP is a Window!

not for me.. then the Handle never changed.
which is only a Container where the real Window are Painting.
what is a Window

greets

[HolgerX]

Hmm..

@EWeiss

1.)

Zitat von EWeiss:

..
you should handle WM_PRINT and WM_PRINTCLIENT. (i think you do nothing of both)

Sorry, you have to read the API-Description by Microsoft correct:

Zitat:

The application that owns the window referenced by hWnd processes the PrintWindow call and renders the image in the device context that is referenced by hdcBlt. The application receives a WM_PRINT message or, if the PW_PRINTCLIENT flag is specified, a WM_PRINTCLIENT message. For more information, see WM_PRINT and WM_PRINTCLIENT.

https://msdn.microsoft.com/de-de/lib...(v=vs.85).aspx


The app with the HWND will receive a WM_PRINT, NOT the caller of PrintWindow!


2.)
Your Screenshoot of your Videoplayer didn't work, of course it use DirectX for the Videoplaying, which is NOT handle by Windows GDI and also NOT could redraw by Microsoft GDI! ('Overlayed Window').



3.)
H := GetWindow(self.Handle, GW_HWNDLAST); // Desktop Give you the LAST Window in the Z-Order, and this IS the Desktopwindow.

Use this Handle only with 'function ScreenshotHidden(wnd: HWND; const bmp: TBitmap): Boolean;' and you will see...

In old Windows the desktop is handled by Progman.exe
(https://en.wikipedia.org/wiki/Program_Manager)

In newer ones it is replaced by explorer.exe
Look in 'Shell' in
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon (per machine)
or
HKCU\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon (per user)
and you will see explorer.exe!

In replacing this you could use your own Desktoptool, like kiosksystems do!!!



4.)
A (i think) real Screenshot could only be made with ALL windows including the top one, of course it make a copy of the Screen DC, where all Windows draw itself in the Z-Order!

The only possibility to make somthing neer a Screenshot is to do the same what MS Windows do in refreshing the Screen: Go throu all Windows and let them 'PrintWindow' himself to the Screen DC!

This is used by my 'Testtool'!

Mircosoft do in this way a lot of things with every Windowprint, like round the corners....
That is, why it could look differnt to the screen!