Add a system-menu item to all applications?

[PeterPanettone 157]

Is there a way to add a system-menu item to all applications? (Not just only to my own application).

[David Heffernan 2345]

You probably need to hook at the other processes. Not easy, and likely to be extremely brittle. Also won't work for any programs that do system menus in a non standard way. 

 

[PeterPanettone 157]

Until now I achieved what I wanted to achieve by intercepting the right-button-mouse-click on the title-bar of any application window. But now I have a system program which also does exactly that, so it overrides my action.

[aehimself 396]

I used the system menu to allow users to change the VCL style of my application. The code looked like this:

Procedure TMyApplicationMainForm.FormShow(Sender: TObject);
Var
 sysmenu: THandle;
 a: Integer;
 flags: Cardinal;
Begin
 sysmenu := GetSystemMenu(Self.Handle, False);
 AppendMenu(sysmenu, MF_SEPARATOR, Word(-1), '');
 For a := Low(_validstyles) To High(_validstyles) Do
  Begin
   flags := MF_STRING;
   If TStyleManager.ActiveStyle.Name = _validstyles[a] Then flags := flags Or MF_CHECKED;
   AppendMenu(sysmenu, flags, WM_USER + 1 + a, PWideChar(_validstyles[a]));
  End;
End;

Instead of Self.Handle I suppose you can supply a different form handle returned by FindWindow. This solution will send a WM_USER message to the form when the appended item is clicked but the foreign one has to process that correctly...

 

I guess you can append to the system menu of an other application, but I doubt that it will ever work correctly. At least not this way 😞

[PeterPanettone 157]

I created a test project (see attachment) which can add a system menu item to my own application or to any other application (tested with notepad: get the notepad window handle).

 

However, reacting to the click event of the added system menu item works only when added to the own application.

 

How can I make it sending a message to my application's window?

 

AddSystemMenuItemToAnyApp.zip

Edited October 3, 2019 by PeterPanettone

[David Heffernan 2345]

Inject code into every process

[PeterPanettone 157]

4 hours ago, David Heffernan said:

Inject code into every process

I don't know any official Delphi library which does process injection. Is there any?

Edited October 4, 2019 by PeterPanettone

[rvk 33]

16 hours ago, PeterPanettone said:

How can I make it sending a message to my application's window?

I don't think 'injecting code' is the best way to go.

 

I think you need to catch the WM_SYSCOMMAND which is sent to the other application(s).

You should be able to do that with SetWindowsHookEx().

https://social.msdn.microsoft.com/Forums/windows/en-US/f87193b7-ccc2-4c30-9b1e-195addd375c8/how-to-intercept-a-wmsyscommand-sent-to-another-app?forum=winforms

 

An example in C++ http://forums.codeguru.com/showthread.php?161054-System-wide-hook-for-WM_SYSCOMMAND

 

[Guest]

25 minutes ago, rvk said:

I don't think 'injecting code' is the best way to go.

SetWindowsHookEx is one of the ways of 'injecting code' on Windows.

 

Documentation: " SetWindowsHookEx can be used to inject a DLL into another process."

 

[David Heffernan 2345]

1 hour ago, Ondrej Kelle said:

SetWindowsHookEx is one of the ways of 'injecting code' on Windows.

 

Documentation: " SetWindowsHookEx can be used to inject a DLL into another process."

 

The example here is of WH_MSGFILTER which I don't think does injection. 

[Remy Lebeau 1394]

4 hours ago, David Heffernan said:

The example here is of WH_MSGFILTER which I don't think does injection. 

Yes, WH_(SYS)MSGFILTER hooks are injected into every process that is being hooked, if hooking other processes than the one that is installing the hook.

[PeterPanettone 157]

I have found a code example that works perfectly and gets a callback when clicking a system menu item in ANY application! It adds a system-wide hook to WM_SYSCOMMAND messages by using a DLL. (Unfortunately, it works only with 32-bit programs):

 

AddSystemMenuItemToAnyApp2.zip

 

I have tried to make it work with 64-bit applications by compiling the projects (EXE and DLL) as Windows 64-bit platform. I did not succeed. I made these changes in the DLL code:

 

• THandle is different on the 64-bit platform: System.UInt64

 

• The error seems to be in the DLL code in the function Hookup in the line GetMsgProcRec^.Hwnd := Hwnd:

   Access violation at address 0000000003585C9F in Modul 'fwGetMsgProc.dll'. Reading from address 0000000000000000.

 

• Also, in the EXE code, in the Button5Click handler I changed:

@Hookup := GetProcAddress(hGetMsgProc, Pchar(LongInt(1)));

to:

@Hookup := GetProcAddress(hGetMsgProc, PAnsichar(LongInt(1)));

 

But, as I said, I did not succeed: There is still the above-mentioned access violation in the DLL code.

 

Could anybody with more experience have a look at the code and successfully compile it to 64-bit?

 

The only code portions you would need to look at are:

• The Button5Click handler in the EXE code

• The DLL code which is just a few lines

Edited October 7, 2019 by PeterPanettone

[rvk 33]

22 minutes ago, PeterPanettone said:

The error seems to be in the DLL code in the function Hookup in the line GetMsgProcRec^.Hwnd := Hwnd:

   Access violation at address 0000000003585C9F in Modul 'fwGetMsgProc.dll'. Reading from address 0000000000000000.

The reason for this is because GetMsgProcRec seems to be nil in the DLL.

It seems that the call to CreateFileMapping fails in 64 bit.

 

For testing this you can add your fwGetMsgProc dll project to the projectgroup of TESTHks and debug the dll-calls.

Set a breakpoint in InitializeDll and you'll see it stops at the first MappedMem line.

Next (on the second try) trace into the procedure with F7 and you'll see the exception for cErrorCreating,['TMappedMem'] is called.

 

You'll see a $FFFFFFFF as parameter, meaning an invalid handle (see https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-createfilemappinga)

But INVALID_HANDLE_VALUE is THandle(-1) which is something different then $FFFFFFFF in 64 bit. (you'll need $FFFFFFFFFFFFFFFF)

 

So change it to

Quote

    fHandle := CreateFileMapping(INVALID_HANDLE_VALUE, nil, PAGE_READWRITE, 0,  Size, PChar(Name));

Now the hook can successfully be installed.

 

(I hadn't much luck with catching anything but now you're a step closer )

 

[PeterPanettone 157]

Unfortunately, when I try to start a debug session for any Win64 project in my Delphi 10.3.1, I get the following error (debugging Win32 projects does work):

 

 

Why is there an error in a CPP file if I try to start a debug session for a DELPHI project?

 

Then I click any button, then this error message pops up:

 

 

So, unfortunately, I cannot debug the Win64 projects.

[PeterPanettone 157]

3 hours ago, rvk said:

fHandle := CreateFileMapping(INVALID_HANDLE_VALUE, nil, PAGE_READWRITE, 0,  Size, PChar(Name));

When I use this call instead of the previous call in \fwGetMsgProc\MapFile.pas then there is no more error in the DLL code in the function Hookup in the line GetMsgProcRec^.Hwnd := Hwnd

 

However, I also do not get a callback when clicking on any system menu item in any application.

Edited October 7, 2019 by PeterPanettone

[rvk 33]

1 minute ago, PeterPanettone said:

However, I also do not get a callback when clicking on any system menu item in any application.

Yep. That was my conclusion too. There still must be something wrong.

 

Using WH_CBT you do get some messages. There supposed to be a HCBT_SYSCOMMAND message containing the information but I haven't looked at it further.

 

[PeterPanettone 157]

It seems that the author of this code is Fred Schetterer. (Los Angeles?). But his website http://www.fredsterware.com/ does not exist anymore, so I don't know how to reach him.

 

Does anybody know him?

[FredS 138]

3 minutes ago, PeterPanettone said:

Does anybody know him

 

Never heard of him 🙂

 

[PeterPanettone 157]

The package he created is here:

 

http://www.vclcomponents.com/Delphi/System_Components/Hooks_Made_Easy-info.html

 

[FredS 138]

22 minutes ago, PeterPanettone said:

The package

 

That was a joke.

That code is from last century, any warranty has expired..

[PeterPanettone 157]

3 minutes ago, FredS said:

 

That was a joke.

That code is from last century, any warranty has expired..

But it works well with 32-bit programs. How can it make to work with BOTH 64-bit programs and 32-bit programs?

[FredS 138]

4 minutes ago, PeterPanettone said:

How can it make to work with BOTH

You need DLLs for both.

[PeterPanettone 157]

28 minutes ago, FredS said:

You need DLLs for both.

That's what I am doing. But it does not work with 64-bit DLLs. See my attached code example above.

[aehimself 396]

9 hours ago, FredS said:

 

Never heard of him 🙂

 

Nice, I actually laughed on this 🙂

[PeterPanettone 157]

1 hour ago, aehimself said:

Nice, I actually laughed on this

Are there any grown-up people here?