C / C++ / MFC

26-Dec-02 10:24

A simple intro to MC++ might help :-

http://www.codeproject.com/managedcpp/mcppintro01.asp

Nish

Author of the romantic comedy

Summer Love and Some more Cricket [New Win]

Review by Shog⁹
Click here for review[NW]

Re: c++ and managed c++

Christian Graus26-Dec-02 13:02

Christian Graus

26-Dec-02 13:02

managed c++ is a marketing con, C++ is the most widely used language on the planet for commercial applications.

Christian

No offense, but I don't really want to encourage the creation of another VB developer.
- Larry Antram 22 Oct 2002

C# will attract all comers, where VB is for IT Journalists and managers - Michael
P Butler 05-12-2002

Again, you can screw up a C/C++ program just as easily as a VB program. OK, maybe not
as easily, but it's certainly doable. - Jamie Nordmeyer - 15-Nov-2002

Re: c++ and managed c++

joshfl27-Dec-02 3:41

joshfl

27-Dec-02 3:41

thanks

Problems with drawing

S O S26-Dec-02 7:58

26-Dec-02 7:58

The CxImage *i is just an image that I want to get drawn onto this CDC.
It works fine if I Draw() straight to the window DC, but if i use this class and try to BitBlt() from this to the window DC, I get nothing.
What could be causing this?

class CSomeDC :<br />
	public CDC<br />
{<br />
	CBitmap bmp;<br />
	CBitmap *bmpOld;<br />
public:<br />
<br />
	Uint32 w, h;<br />
<br />
	void Init(CxImage *i)<br />
	{<br />
		w = i->GetWidth();<br />
		h = i->GetHeight();<br />
<br />
		VERIFY(CreateCompatibleDC(0));<br />
		VERIFY(bmp.CreateCompatibleBitmap(this, w, h));<br />
		bmpOld = (CBitmap*)SelectObject(bmp);<br />
		i->Draw(m_hDC);	// Works if I do this on the window DC straight away<br />
	}<br />
};

Neville Franks26-Dec-02 10:02

Neville Franks

26-Dec-02 10:02

Locked Ghost wrote:
VERIFY(CreateCompatibleDC(0));

For a start why is 0 being passed here. It should be 'this' me thinks.

Neville Franks, Author of ED for Windows. www.getsoft.com
Make money with our new Affilate program

S O S26-Dec-02 11:04

26-Dec-02 11:04

0 = Current display DC or something like that(Memory bad. From MSDN)

this? well, why would I want to create a DC compatible with itself, which has not been created yet? :p

For Mr.Locked Ghost

HellShrimp4free26-Dec-02 11:22

HellShrimp4free

26-Dec-02 11:22

hey Brian do u know Chris-de-Burgh ? Big Grin | :-D

-=Ehsan-de-Burgh=- Roll eyes | :rolleyes:

Re: For Mr.Locked Ghost

S O S26-Dec-02 21:47

26-Dec-02 21:47

Brian? Chris-de-Burgh? Never heard of either one

Neville Franks26-Dec-02 13:00

Neville Franks

26-Dec-02 13:00

Locked Ghost wrote:
0 = Current display DC or something like that(Memory bad. From MSDN)

I think its for the Desktop. Is that what you want?

Locked Ghost wrote:
this? well, why would I want to create a DC compatible with itself, which has not been created yet? :p

Because that's what you do with memory dc's. Have a look around CP for CMemDC by Keith Rule.

Neville Franks, Author of ED for Windows. www.getsoft.com
Make money with our new Affilate program

S O S26-Dec-02 21:49

26-Dec-02 21:49

Neville Franks wrote:
Because that's what you do with memory dc's. Have a look around CP for CMemDC by Keith Rule.

Tried, still doesn't work Frown | :(

And CMemDC does not do that actually.

Iain Clarke, Warrior Programmer

Iain Clarke, Warrior Programmer27-Dec-02 7:43

27-Dec-02 7:43

I've run into this myself in the past. You are creating a DC which initially has a mono 1x1 bitmap
selected into it (look at ::CreateCompatible DC...) You need to create a HBITMAP compatible with the
end DC (e.g. Screen).

You need something like:

void Init (CxImage *i)
{
    CWindowDC dcScreen (CWnd::FromHandle (::GetDesktopWindow ()));

    w = i->GetWidth();
    h = i->GetHeight();

    VERIFY(CreateCompatibleDC(&dcScreen));    // <-- Changed to make it more obvious.
    ////////////////////////////
    VERIFY(bmp.CreateCompatibleBitmap(&dcScreen, w, h)); // <-- Changed
    ////////////////////////////
    bmpOld = (CBitmap*)SelectObject(bmp);
    i->Draw(m_hDC); // Works if I do this on the window DC straight away
}

I hope this helps,

Iain.

S O S27-Dec-02 8:18

27-Dec-02 8:18

Yes!! It works Smile | :)

Huge thanks to you! Smile | :)

In related things, can you tellme why this destructor gives me an acccess violation?
I've seen the exact kind of thing(Selecting the old bitmap back) done in destructors before... hmm?

class CTilesetDC :<br />
	public CDC<br />
{<br />
	CBitmap bmp;<br />
	CBitmap *bmpOld;<br />
public:<br />
<br />
	Uint32 w, h;<br />
<br />
	CTilesetDC(CxImage *i, CDC *target)<br />
	{<br />
		w = i->GetWidth();<br />
		h = i->GetHeight();<br />
<br />
		VERIFY(CreateCompatibleDC(target));<br />
		VERIFY(bmp.CreateCompatibleBitmap(target, w, h));<br />
		bmpOld = (CBitmap*)SelectObject(bmp);<br />
		i->Draw(GetSafeHdc());<br />
	}<br />
<br />
	~CTilesetDC()<br />
	{<br />
		SelectObject(bmpOld);<br />
	}<br />
};

Iain Clarke, Warrior Programmer

Iain Clarke, Warrior Programmer28-Dec-02 13:11

28-Dec-02 13:11

I should have spotted this in my first reply. CDC::SelectObject (CBitmap *) returns a pointer
to a temporary CBitmap. To quote:

This function may return a pointer to a temporary object. This temporary object is only valid
during the processing of one Windows message. For more information, see CGdiObject::FromHandle

After a while, the CBitmap pointed to by bmpOld is deleted by MFC; so when you try to delete it,
an exception is raised. This is one of the reasons I use HANDLES...

You could change your class to

<br />
class CTestDC : public CDC<br />
{<br />
    ....<br />
    CBitmap    bmpOld;<br />
    ....<br />
<br />
    CTestDC (....)<br />
    {<br />
        ....<br />
        bmpOld.Attach (SelectObject (&bmpNew)->Detach ());<br />
        ....<br />
    }<br />
<br />
    ~CTestDC ()<br />
    {<br />
        SelectObject (&bmpOld);<br />
        bmpOld.Detach (); // <-- If you don't do this, then ~CBitmap will call DeleteObject, which we don't to be purist...<br />
    }<br />
}<br />

I hope this helps.

Iain.

Metafile

Anthony988726-Dec-02 7:48

Anthony9887

26-Dec-02 7:48

I'm trying to resize of metafile. Is there a function I can use.

Thanks

SendMessage and BN_CLICKED doesn't work

User 665826-Dec-02 6:40

User 6658

26-Dec-02 6:40

Hi
I've got a real strange problem. I want to simulate a button-press in another app. I have a HWND wndButton, which is definately valid. Now I want to simulate the pressing of the button:
::SendMessage(::GetParent(wndButton),WM_COMMAND,MAKEWORD(::GetDlgCtrlID(wndButton),BN_CLICKED),(LPARAM)wndButton);
But this doesn't work. Does anybody know why? It works in other programs Confused | :confused:

Update: The window doesn't even react on ShowWindow(SW_HIDE), although my HWND to the window is valid. What the hell is going on here? Eek! | :eek:

regards
Greg

modified 12-Sep-18 21:01pm.

Re: SendMessage and BN_CLICKED doesn't work

AlexO26-Dec-02 6:51

AlexO

26-Dec-02 6:51

Are you sure about "(::GetParent(wndButton),"? Parent might not be what you expect. Could you check it with Spy?

Re: SendMessage and BN_CLICKED doesn't work

User 665826-Dec-02 7:17

User 6658

26-Dec-02 7:17

Oh, forget my question, thanks for your effords Wink | ;)

This code was inside a loop that never was reached Big Grin | :-D

regards

modified 12-Sep-18 21:01pm.

Re: SendMessage and BN_CLICKED doesn't work

Brian Delahunty26-Dec-02 8:07

Brian Delahunty

26-Dec-02 8:07

Gregor S. wrote:
This code was inside a loop that never was reached

I don't like having to debug code but situations like this proves it's a complete necessity. Big Grin | :-D

Regards,
Brian Dela Smile | :)

Owner of a process

Nish Nishant26-Dec-02 6:09

26-Dec-02 6:09

Hey guys,

Is it possible to find the owner (the user) of a process once we have the module handle?

Regards,
Nish

Author of the romantic comedy

Summer Love and Some more Cricket [New Win]

Review by Shog⁹
Click here for review[NW]

AlexO26-Dec-02 6:35

AlexO

26-Dec-02 6:35

It is defiantly possible, procexp.exe(sysinternals.com) does that. Check out sysinternals.com they should have some source code for that.

Nish Nishant26-Dec-02 7:19

26-Dec-02 7:19

Unfortunately they dont give out the source code for that one Frown | :-(

Nish

Author of the romantic comedy

Summer Love and Some more Cricket [New Win]

Review by Shog⁹
Click here for review[NW]

Mike Nordell26-Dec-02 7:35

Mike Nordell

26-Dec-02 7:35

Nishant S wrote:
Unfortunately they dont give out the source code for that one

Then it's probably impossible using Win32, forcing use of either (DDK documented) NT API, or (more likely, since this could be something useful) it's completely undocumented.

Perhaps you could disassemble the sysinternals code and see how its done? I've got a feeling this is in the NT API QueryObjectInformation (or something like that).

Nish Nishant26-Dec-02 8:18

26-Dec-02 8:18

Mike Nordell wrote:
I've got a feeling this is in the NT API QueryObjectInformation (or something like that).

Thanks Mike, I'll take a look at this

Nish

Author of the romantic comedy

Summer Love and Some more Cricket [New Win]

Review by Shog⁹
Click here for review[NW]

Nish Nishant26-Dec-02 8:28