how to draw the background bmp for the statusbar? - C / C++ / MFC Discussion Boards

monrobot1331-Mar-04 8:39

31-Mar-04 8:39

ns wrote:
Why wasnt PaintDC suitable for TextOut

It wasn't that the CPaintDC wasn't suitable for a TextOut call it's that it wasn't suitable for where you were using it. CPaintDC should only be used in an OnPaint message handler. The reason behind this, as far as I know, is that it calls some functions (BeginPaint, EndPaint) that set the update region (area you can actually "paint" in) and in your button handler there probably hasn't been any part of your window that's been invalidated, therefore a CPaintDC wouldn't have any valid drawing area.

- Aaron

Re: TextOut()

GflPower31-Mar-04 13:27

GflPower

31-Mar-04 13:27

在这个论坛上必须发英文吗
I'm sorry!

I can't speak english

CDC* dc;

dc = GetDC();

dc->textout();

d

Finding a structures address

Xen3h31-Mar-04 4:27

Xen3h

31-Mar-04 4:27

I use some structures in an app using pointers, basically everytime the program gets updated these addresses change slightly, I usually get told by someone what the address is.

Basically I want to be able to automatically find the address of the structure in the app, but i'm not sure how to do it.. I think i remember someone saying pattern searching or something.

Any help is appreciated. Smile | :)

Re: Finding a structures address

David Crow31-Mar-04 8:06

David Crow

31-Mar-04 8:06

I think I know what you are asking, but your comments make me think otherwise. Have you tried the address-of operator?

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Finding a structures address

Prakash Nadar31-Mar-04 14:44

Prakash Nadar

31-Mar-04 14:44

What do you use the address for ? is it a memeory address or a file offset number ?

MSN Messenger.
prakashnadar@msn.com

Tip of the day of visual C++ IDE.
"We use it before you do! Visual C++ was developed using Visual C++"

Re: Finding a structures address

gUrM33T31-Mar-04 16:47

gUrM33T

31-Mar-04 16:47

Your question is not clear.

Gurmeet S. Kochar

If you believe in God, it's because of the Devil

Re: Finding a structures address

John R. Shaw31-Mar-04 21:56

John R. Shaw

31-Mar-04 21:56

This question makes no since! What do you mean by "...someone what the address is." Either the code knows what the address is or it doesn't. You might know what the address is at a given run of the program and your debugger might give you the same address every time you rebuild, until you modify the code. But the address may be relitive to the base address of your program or it may be allocated (could be anywhere). You should never need to know the actual address (except maybe when debugging). Pattern searching has nothing to do with finding an address.

/* in C */
struct whatever {...};
struct whatever* pAddr; /* uninitialized pointer/address */
or
myfunct(struct whatever* pAddr)
{
    /* modify stucture whatever */
}

// in C++
struct whaterver {...};
whatever* pAddr; /* uninitialized pointer/address */
or
myfunct(whatever* pAddr)
{
    /* modify stucture whatever */
}

INTP

how to draw the background bmp for the statusbar?

benben31-Mar-04 3:52

benben

31-Mar-04 3:52

Hi:
I want to let the CStatusBar support background bmp(just like CRebar's background).I try to draw the bmp in the onerasebackground() function,but it seems that this way only works in winxp;in win98/me/2000,the background doesn't show correctly.Could you give me any idea or any examplt?

Thanks
Benben

Re: how to draw the background bmp for the statusbar?

Alexander ^M.,1-Apr-04 3:44

Alexander ^M.,

1-Apr-04 3:44

try OnPaint

Don't try it, just do it! Wink | ;-)

Thank you very much!

benben1-Apr-04 17:23

benben

1-Apr-04 17:23

Thanks
Benben

Windows Service vs. Sockets

RickyC31-Mar-04 3:42

RickyC

31-Mar-04 3:42

Hy everybody!
I'm having a little problem in a Windows Service (DOS App)...
I create a CAsyncSocket derived class to work as a server. I use the Listen(), and after that, I wait for a connection on my OnAccept(). Everything works fine... the socket is created, is listening (so I hope)... but when a connection request comes, nothing happens... and don't run the OnAccept mapped function. Frown | :(

(where I'll make Accept() in another socket)
The Unix process (my client) says to me that is connected and begin send data to me... but I even know that I'm connected with it. Confused | :confused:

Does anybody knows what could be happen?

thanks folks,
cheers!

Message Pump Missing?

Xiangyang Liu 刘向阳31-Mar-04 4:41

Xiangyang Liu 刘向阳

31-Mar-04 4:41

Here is a possible cause of your problem:

The OnAccept() method is not called because there is no message pump in your windows service.

Here is my understanding (see MFC source code): When a request comes from a remote program, it is turned into a windows WM_SOCKET_NOTIFY message and posted to an internal window used by CAsynSocket. When the WM_SOCKET_NOTIFY message is processed by MFC, it will invoke the event handlers such as OnAccept, OnReceive, etc. Unless you added a message loop to your windows service, the WM_SOCKET_NOTIFY message will never be processed.

If you cut and paste your code into a MFC dialog based application, assuming there is no other bug, it will work.

If that is confirmed to be the problem, there are at least two relatively easy solutions.

1. Start a separate thread from the windows service. Create the socket in this new thread, call Create/Bind/Listen for the socket, then use a loop to call Accept/Reciev/Send (i.e. don't rely on the OnAccept notification).

2. Move everything to a dialog based application, when the program works, use this special windows service[^] to run your application.

Good luck.

P.S. Solution 1 does not work if multiple clients have to connect to your server simultaneously, in which case you need to add a message pump and rely on the socket events.

My articles and software tools

Re: Message Pump Missing?

RickyC31-Mar-04 5:59

RickyC

31-Mar-04 5:59

Ok, thanks Xiangyang Liu
I'll see if this is the problem, and if so, I'll try one of your sugestions.
Thanks a lot! Smile | :)

cheers!

Re: Windows Service vs. Sockets

Robert M Greene31-Mar-04 16:00

Robert M Greene

31-Mar-04 16:00

The MFC socket classes depend on a message loop to process the notifications properly. Services don't have message loops (normally anyways) so I always use the low level socket routines for services. Check MSDN and they will explain the limitations of CSocket amd CAsyncSocket.

.............................
There's nothing like the sound of incoming rifle and mortar rounds to cure the blues. No matter how down you are, you take an active and immediate interest in life.

Re: What is "Visual Studio (MSI)"?

Vasiliy Baranov31-Mar-04 3:36

Vasiliy Baranov

31-Mar-04 3:36

Well, Microsoft Installer (MSI) is a technology (or file format) rather than a tool for authoring installations. InstalShield and Wise produce MSI installations too.

Win 32 error

jetournier31-Mar-04 2:55

jetournier

31-Mar-04 2:55

Hello
Could anyone help me about the "Win 32 error 267" I get when I run a .exe I just correctly compiled with Visual C++?
The associated message is: "Could not execute: invalid directory"
As I'm a beginner, it may be a very stupid mistake....
Thank you in advance

JET

Re: Win 32 error

Antti Keskinen31-Mar-04 3:26

Antti Keskinen

31-Mar-04 3:26

Is your executable (code) attempting to open a file or a document that does not exist, or does it specify a directory that does not exist ?

That is the apparent reason for the error, so you should check your code throughoghly. Then, set breakpoints into the code and use the debugger to determine the point where this error is caused.

It might also be that your user account has no execution priviledges on the directory where the executable resides. In this case, contact the Systems Administrator for a solution.

-Antti Keskinen

----------------------------------------------
The definition of impossible is strictly dependant
on what we think is possible.

Re: Win 32 error

jetournier1-Apr-04 19:35

jetournier

1-Apr-04 19:35

Thanks for the answer.
In fact the error happened before the entry point of the program, so no breakpoint could be useful. Cry | :((

It was in fact in options/settings/debug/working directory: as somebody gave me an example of a project, there was something specified that didn't correspond to a real directory on MY computer....
So I erased this line and now I can continue Big Grin | :-D

JET

SetCursor

ns31-Mar-04 2:46

31-Mar-04 2:46

I want to ctrl-RClick on a spot and make my cursor change to a custom one (its like a ruler which changes its length depending on which area I click the mouse in). THis cursor image has to be generated on the fly so it cant be part of the resources like an IDI_MYCURSOR. What kind of a file do I need to generate that I can use with SetCursor()? Do I have to "draw" my data into write out a .bmp file onto the hard drive and then reload with ::LoadImage() in my MFC app, to get the handle that I need for ::SetCursor() ? Is there a link on how to make a custom cursor in code somewhere perhaps?
Thanks,
ns

Re: SetCursor

Antti Keskinen31-Mar-04 3:23

Antti Keskinen

31-Mar-04 3:23

This sounds very difficult indeed.

Are you certain that it is the cursor length that must change ? Could it be that your cursor can remain a single dot, and then you just purely draw on the device context of the window to achieve your effects ? How about hiding the cursor altogether ?

It is, however, possible to create custom cursor. All you need to do is to create a new, blank icon object and specify two masks for it, AND and XOR. These masks are used to draw the monochrome icon.

For a code example, go to MSDN via this[^] link and expand the second code example there. As you can see, creating run-time icons is a BIG work, but doable.

Read the entire section carefully through before starting, pay especial attention on the truth table used. Then understand that the 4 bytes of each line cover 32 bits of the line (4 * 8 = 32). Then, draw your icon on a paper, and finally, onto the two masks.

-Antti Keskinen

----------------------------------------------
The definition of impossible is strictly dependant
on what we think is possible.

Re: SetCursor

ns31-Mar-04 3:40

31-Mar-04 3:40

Thanks for the link. I was debating on this approach because I thought it would be easier than bitblting onto the surface. I havent done either thing before ....
Smile | :)

Re: SetCursor

ns31-Mar-04 4:05

31-Mar-04 4:05

hinst

hIcon3 = ::CreateIcon( hinst // application instance
32, // icon width
32, // icon height
1, // number of XOR planes
1, // number of bits per pixel
ANDmaskIcon, // AND bitmask
XORmaskIcon);

How do I get the hinst in MFC?

I didnt see an MFC version of CreateIcon like there is for DrawIcon which I see can be used like CPaintDC dc
dc.DrawIcon()
thanks

Also I want to be able to get rid of the icon using a button or a leftclick or something. This is happening on a picture in an image box, so if theres no obvious way, I can just reload the picture after the icon isnt needed anymore...

doyou think thats the simplest thing to do? What if I ddidnt have a reloadable picture? How would I get rid of the icon then?

Thanks again..

Re: SetCursor

Antti Keskinen31-Mar-04 4:49

Antti Keskinen

31-Mar-04 4:49

There is no MFC version, as there is no icon wrapper class (CIcon) for MFC. All this is handled by the CBitmap class, and unfortunately, it does not directly support creation of icons.

Under MFC, you can get the application instance handle by calling a global (macro) function AfxGetInstanceHandle. Alternatively, you can query for AfxGetApp to get the CWinApp class, and use it's CWinApp::m_hInstance data member. The prior function call is a macro wrapper for this approach.

Nothing prevents you from using the Win32 API calls ::CreateIcon and ::DestroyIcon to manage a HICON object in the MFC environment. Note, that the MFC's clean-up framework is not available, so you must be very careful to release and destroy all reserved memory and objects, otherwise your application will cause memory leaks.

You can set the cursor by using ::SetCursor and restore the default cursor by using the same method. Know, though, that for MFC classes derived from CWnd, you must overwrite the CWnd::SetCursor method and determine some sort of a method to decide what cursor to load (by using ::SetCursor).

The default implementation of this function always sends the call down to the base class, and thus, the resulting icon will always be the default one. This manifests itself so that if you call ::SetCursor without overriding the respective method, then the cursor will change, but instantly as you move the mouse (or the cursor), it will be reverted back to the original one.

To restore the icon when it is no longer needed, call ::SetCursor with IDC_ARROW parameter, or pass the call to the base class, which will use the IDC_ARROW as default. After the icon has been detached from the cursor, you can destroy it (the icon) and free the memory it reserved.

-Antti Keskinen

----------------------------------------------
The definition of impossible is strictly dependant
on what we think is possible.

Re: SetCursor

ns31-Mar-04 8:51

31-Mar-04 8:51

Thank you for the detailed answer. Appreciate it .
ns

Problems with GetMsgProc & WH_GETMESSAGE using SetWindowsHookEx

triptiarora31-Mar-04 1:57

triptiarora

31-Mar-04 1:57

I am trying to hook a 3rd Party Window.

Just a little background:
After I get the handle of this window, I use the 'GetWindowThreadProcessId' to get the Thread Id of the window.
Code:
dwThreadId = ::GetWindowThreadProcessId(hwndTskMgr, NULL);
-----------------------------------------------------------------------------

Then I am calling the 'SetWindowsHookEx' function.
Code:
g_hhook = ::SetWindowsHookEx(WH_GETMESSAGE, GetMsgProc, g_hinstDll, dwThreadId);
-----------------------------------------------------------------------------

In function 'GetMsgProc', I am trying to monitor the 'SB_SETTEXT' or 'WM_SETTEXT' message to be able to detect when the ‘3rd Party Window’ sets the text of the status bar.
Code:
LRESULT CALLBACK GetMsgProc(int code, WPARAM wParam, LPARAM lParam)
{
char msg5[255];
wsprintf(msg5, "Inside GetMsgProc & code = %d",code);
::OutputDebugString(msg5); // Just a test

if (code < 0)
{
return CallNextHookEx(g_hhook, code, wParam, lParam);
}
if ((code == HC_ACTION) && (wParam == PM_REMOVE))
{
::OutputDebugString("In code is HC"); // Just a test

MSG *pMsg = (MSG*)lParam;
if(pMsg->message == WM_SETTEXT)
::OutputDebugString("WM_SETTEXT was found\n");
else
::OutputDebugString("WM_SETTEXT was not found\n");
}

return CallNextHookEx(g_hhook, code, wParam, lParam);
}
-----------------------------------------------------------------------------

Problem:
In 'SetWindowsHookEx' I am using 'WH_GETMESSAGE' type of hook procedure, which would give a call to 'GetMsgProc'.
But the CALLBACK GetMsgProc function is not getting called. And some time the GetMsgProc function gets called but my whole system gets stuck up and hangs. And then I need to restart the system.

I have gone through a lot of code in 'CodeGuru.com' as well as in 'CodeProject.com', and have tried many combinations but still am not able to hook the various messages of the Task Manager. I am not able to figure out where I am going wrong.

Any help in this regard would be really appreciated.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.