I'll try this... It might take a while, since I'm sitting at a UNIX system right now :-)
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Question
Get window handle from process ID
From a newsgroup I got hold on this piece of sourcecode, which is supposed to get me the window handle from a processID. Well my question is in fact quite simple. It doesn't work, but whats wrong. I know that the if statement in the callback function EnumProc() never equals true, so no handle can be returned. Unfortunatly I can't seem to udnerstand exactly what is going on. Please help
Type
TEnumData = Record
hW: HWND;
pID: DWORD;
End;
Function EnumProc( hw: HWND; Var data: TEnumData ): Bool; stdcall;
Var
pID: DWORD;
Begin
Result := True;
If (GetWindowLong(hw, GWL_HWNDPARENT) = 0) and
(IsWindowVisible( hw ) or IsIconic(hw)) and
((GetWindowLong(hw, GWL_EXSTYLE) and WS_EX_APPWINDOW) <> 0)
Then Begin
GetWindowThreadProcessID( hw, @pID );
If pID = data.pID Then Begin
data.hW := hW;
Result := False;
End; { If }
End; { If }
End; { EnumProc }
Function WindowFromProcessID( pID: DWORD ): HWND;
Var
data: TEnumData;
Begin
data.pID := pID;
data.hW := 0;
EnumWindows( @EnumProc, longint(@data) );
Result := data.hW;
End; { WindowFromProcessID }
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Answers
I think there's a difference between threadid and processid. When I find the process ID using WinSight32 and insert in instead of GetCurrentThreadId, the returned handle is 0, but if I leave GetCUrrentThreadId, then I get a handle (of cource not the one I want)
One other thing... I am having problems using a callback function. When I call EnumWindows(@EnumProc, 0) where EnumProc is:
function EmunProc(app_hnd : HWND; lparam : DWORD) : boolean;
begin
// some stuff here
Form1.Memo1.Lines.Add(IntT
end;
The memo component gets filled with the same handle a lot of times. Isn't EnumWIndows suppored to pass the handle of all top level windows in turn to the CallBack function. What am I doing wrong ??
No you need to specify which windows..... Here is an example...
function GetWinProc(Handle : HWND; lParam : LPARAM):Boolean;stdcall;
var
Name : array[0..MAX_PATH] of char;
begin
if IsWindowVisible(Handle) then begin
GetWindowText(Handle, Name, SizeOf(Name));
if not(Name = '') then
Form1.Listbox1.Items.Add(N
Result := true;
end;
end;
procedure TForm1.Button1Click(Sender
begin
ListBox1.Items.Clear; //Just to clean the listbox so it clears it before filling it again..
EnumWindows(@GetWinProc,0)
end;
This will get all visible windows, not the one that don't have names like popup menus and similar....
Hoe this helps a bit!
btw- I don't know why the processID isn't working... Gotta try it on my Delphi, and will get back to you soon.///
Regards,
Viktor Ivanov
Oh, ok.... Cool... You said you were going to a High School so I though were still there... But what I missed was that I didn't see you registered in 97 :-| Sorry... Anyway, I'm 16 and really like programming in Delphi. Actually it's my first programming language and I started programming in it a bit more than 3 months...maybe 4 months.... ago. I've learned a little C/C++ and I'm learning assmbler right now :-)
btw- What kind of stuff do you study in Computer Science....????
Regards,
Viktor Ivanov
Wow, it's been 2 years since I posted to this question, and there's a comment waiting for me now. Anyways, I don't really have time to write any code for you, but here is the principle.
You can use ShellExecute() to execute your application, and then you can use FindWindow() to track down the handle of your window. There are other more complex methods to do it, but I don't have the time, as I previously mentioned.
Regards,
Viktor
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by: viktornetPosted on 1998-10-17 at 12:49:21ID: 1343243
How about this code???
var
DaHandle : HWND;
function GetHwnd(Handle : HWND; lParam : LPARAM) : Boolean;stdcall;
begin
DaHandle := Handle;
Result := True;
end;
procedure TForm1.Button1Click(Sender
var
Name : array [0..MAX_PATH] of char;
begin
if EnumThreadWindows(GetCurre
GetWindowText(DaHandle, Name, SizeOf(Name));//YOu can comment out this
Button1.Caption := StrPas(Name);//and this
//and use the DaHandle that has been returned by the EnumThreadWindows()
end;
end;