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<ctrl><alt> Have you ever look at how many processes might be running on you machine at one time. BitBlt() is like every other piece of code running on youre machine, it is a matter of priority (every body gets a slice of the processors time [at least they are supposed to]). I discover a virus once, becuase I notice that processor time was being eatin (slow down in resonse time).
May be someone can give you an idea for improving the speed if you explained why the graph is rendered in pieces, instead of as a whole.
INTP
"The more help VB provides VB programmers, the more miserable your life as a C++ programmer becomes."
Andrew W. Troelsen
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hai..
I'm working on win32 vc++..I want to know waht is the window message that is processed when the window is maximized and minimized..
thanks.
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Look at WM_SIZE.
wParam = SIZE_MAXIMIZED, SIZE_MINIMIZED, SIZE_RESTORED, etc.
lParam = cx -> lo word cy -> hi word
Hope this helps.
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Is thera any way for
int a = 5;
int b;
b's memory address point to a's?
so &b would equal to &a.
Or the only way is create a pointer to do it
int a = 5;
int *b;
b = &a;
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Or the only way is create a pointer to do it
me think yes.
Maximilien Lincourt
Your Head A Splode - Strong Bad
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Isn't a pointer just a long integer anyways? I didn't try this, but I don't see a reason why a long int couldn't hold an address...it doesn't care if it's an address...as long as it is a value which matches its type.
I don't know why you'd do this though...that's what pointers are for...
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This will break 64 bit code (AMD64) where pointers are 64 bits and integers are 32 bits.
John
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I believe you could use references for this:
int a = 5;
int &b = a;
a = 500; //now a == 500 AND b == 500
b = 1234; //now a == 1234 AND b == 1234
I'm not totally sure that's right though, you should probably step through the code in a debugger and check.
Hope that helps,
Pete
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I stand corrected, forgot about references.
int a = 5;
int &b = a;
in that case, &a == &b ( the address of a and b are the same).
Maximilien Lincourt
Your Head A Splode - Strong Bad
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Thanks. I totally forgot about that one
How would I go about so b's memory address would point to a's memory address?
class CFirst(){
private:
int a;
public:
CFirst(){ a = 25; };
int ReturnA(){ return(a); };
};
class CSecond(){
private
int b;
};
int main(){
CFirst a;
return 0;
}
The stuff I am doing is a little bit more complex. I want to point b's link list data to a's link list's data and then remove the la ink list(without destroying the data)
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You know, you really should join up and sign in if you want people to help you out Membership is the key...
Anyway, something along these lines might point you in the right direction:
class CFirst
{
...
...
public:
int &GetReferenceToA()
{ return a; }
...
...
}
class CSecond
{
public:
class CSecond( int &numberToAttachTo )
: b( numberToAttachTo )
{}
protected:
int &b;
};
int main()
{
CFirst instanceOfFirst;
CSecond instanceOfSecond( instanceOfFirst.GetReferenceToA() );
...
...
}
I don't know how much that helps. There would be quite a few ways of initializing the 'connection' between a and b.
One thing to note is that any member variables of CSecond() that are references MUST be initailized at construction time. This makes them more fiddly to use than pointers, IMHO.
HTH,
Pete
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The stuff I am doing is a little bit more complex. I want to point b's link list data to a's link list's data and then remove the la ink list(without destroying the data)
you can't really do that, at least the way I think you want to do it.
if your data ( a or b ) are not dynamically allocated ( new or malloc ) , then, you will need to copy the data; and passing a reference a to b and then removing a will invalidate b ( at best ).
in your example, ReturnA copies the data.
but for example, if your CFirst looks like :
class CFirst {
int* a; // will be allocated and assigned.
int* ReturnA( return a;};
}
then, you return the address of a to whoever receives it;
int* b = ReturnA();
but you will need to keep track of allocation and deallocation.
Maximilien Lincourt
Your Head A Splode - Strong Bad
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I have an account I just keep forgetting to log in.
int* ReturnA(){ return a;};
doesn't work.
I have been trying to get function to return pointer
Nevermind I am an idiot. Forgot to add () when I call the function
You can't assign &b on the fly right? Only at the intitalization.
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You could create a 'reference'. A reference variable is somewhat like a mix between a pointer and a copy variable. References are much like synonymes with same type.
For example:
int A = 5;
int& B = A; Now both &A and &B operations return the same value, A's address. If A is changed, B changes, and vice versa. In syntactical terms, however, they are the same thing. Same thing (an integer variable) with two seperate names.
-Antti Keskinen
----------------------------------------------
"If we wrote a report stating we saw a jet fighter with a howitzer, who's going to believe us ?"
-- R.A.F. pilot quote on seeing a Me 262 armed with a 50mm Mauser cannon.
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I only saw part of the other answers! But...
-----------------------------------------------------------------------------
int A = 5; // declared and intialized
int *pB = &A; // ponter to int declared and intialized to address of A
// pB is an inderect reference to A, which means it holds the address of A
// &A is the address of A (aka. indirect reference)
// *pB is a dereferncenced pointer (aka. direct reference)
int &C = A; // direct reference declared and intialized
// C and A are both references to the same data (memory location)
// Therefor, &A = pB = &C and A = *pB = C.
-----------------------------------------------------------------------------
Thats it, in a nut shell.
-----------------------------------------------------------------------------
It seems complicated, don't it. Given time it will become second nature to you.
-----------------------------------------------------------------------------
This might help:
#include <stdio.h>
int main(void)
{
int A = 5;
int *pB = &A;
int &rC = A;
prinf(
"Address of A = %p, Value of A = %d\n"
"Address of pB = %p, Address stored in pB = %p, Value of *pB = %d\n"
"Address of rC = %p, Value of rC = %d\n",
&A, A,
&pB, pB, *pB,
&rC, rC);
return 0;
}
I have not tested the code above, but is should give you an idea of the relationships between pointers and references.
INTP
"The more help VB provides VB programmers, the more miserable your life as a C++ programmer becomes."
Andrew W. Troelsen
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can we create a rich colored icon - i.e. 256 colors or more - for VC?
includeh10
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hi,
you can, but not with resource editor supplied with VC.
GSte
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Is it possible to use the standard CFileDialog, and dynamically hide certain controls before it is displayed? I am able to create a hook function to trap the WM_NOTIFY/CDN_INITDONE message sequence, but cannot seem to grab the handles for the controls on the dialog at this stage. Can anyone enlighten me?
I've tried several different versions of the following code, to no avail. What am I doing wrong?
CString CCustomizedDialog::GetFolder()
{
OPENFILENAME ofn;
memset(&ofn, 0, sizeof(OPENFILENAME));
ofn.lStructSize = sizeof(OPENFILENAME);
ofn.hwndOwner = NULL; //or any valid parent window handle.
ofn.hInstance = AfxGetInstanceHandle(); //or your hinstance variable if you are not using mfc support.
ofn.lpstrFilter = _T("Text Files\0*.txt\0\0"); //modify this for any other filter.
ofn.lpstrCustomFilter = NULL;
ofn.nFilterIndex = 0;
ofn.lpstrFile = new TCHAR[256];
memset(ofn.lpstrFile, 0, 256 * sizeof(TCHAR));
ofn.nMaxFile = 256;
ofn.lpstrFileTitle = NULL;
ofn.lpstrInitialDir = NULL;
ofn.lpstrTitle = NULL;
ofn.Flags = OFN_EXPLORER | OFN_ENABLEHOOK | OFN_ENABLETEMPLATE;
ofn.lpfnHook = OFNHookProc; //Custom hook procedure.
ofn.lpTemplateName = MAKEINTRESOURCE(FILEOPENORD);
GetOpenFileName(&ofn);
CString theReturnString = ofn.lpstrFile;
delete [] ofn.lpstrFile;
return theReturnString;
}
//Custom hook procedure stub. Must remain outside of the class
UINT CALLBACK OFNHookProc(
HWND hdlg, // handle to child dialog box
UINT uiMsg, // message identifier
WPARAM wParam, // message parameter
LPARAM lParam // message parameter
)
{
// set a flag so we know when the dialog has been initialized
static BOOL isInitialized;
CEdit* theEditBox;
//Do your message processing here.
//Return 0 if you need the default dialog box procedure to process
switch (uiMsg)
case WM_NOTIFY:
{
AfxMessageBox("Notify was caught!");
if(isInitialized == TRUE)
{
HWND theParent = GetParent(hdlg);
if(theParent != NULL)
{
theEditBox = (CEdit*)GetDlgItem(theParent,edt1);
theEditBox->SetWindowText(_T("Readme.txt"));
}
}
/// catch CDN_INITDONE message so we can
/// change the look of the dialog
if(((OFNOTIFY *)lParam)->hdr.code == CDN_INITDONE)
{
AfxMessageBox("INITDONE was caught!");
isInitialized = true;
HWND theDlg = GetParent(hdlg);
CString theMsg = "The ParentHWND: ";
// theMsg += theDlg;
// AfxMessageBox();
}
}
return 0;
}
Thanks,
--Mark
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You might consider using Spy++ to display the dialog and then get info on the control in question - this will give you the control's ID, which you could then use with the GetDlgItem() call, passing in the ID that Spy++ discovered.
¡El diablo está en mis pantalones! ¡Mire, mire!
Real Mentats use only 100% pure, unfooled around with Sapho Juice(tm)!
SELECT * FROM User WHERE Clue > 0
0 rows returned
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Hi Jim,
Thanks for the quick reply. I think the problem is with getting a handle to the actual dialog on which the control is drawn. I have to pass this handle (I believe) to the GetDltItem() function. I have tried both the hdlg parameter, and GetParent(hdlg) in the hook function, but neither one seems to work. I have been looking at Spy++, and the handle I get for the actual dialog does not match either one of these...
I will look at it again, though. Thanks.
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Since you're using MFC (or it appears so), it might be a little easier if you subclass CFileDialog and overload it's OnInitDialog member function. In the subclass OnInitDialog function, you can use GetDlgItem(), using the control IDs that you obtain using Spy++, to get pointers to the dialog controls you want to hide.
If you do this way, you won't need a special dialog proc and you won't have to deal with the OPENFILENAME structure.
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Yes, thank you. I had originally tried doing this, but was unable to get handles to the controls on the dialog. I was using the constants defined in dlgs.h (edt1) to grab handles (GetDlgItem()). Are these constants not correct? I'm confused as to why I would need to use spy++ to get the ids...are they not constant?
Thanks for all the help.
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Okay, I tried this, and there are two problems (unless I'm doing something wrong). The first is, spy++ gives me handles to windows, not control id's. The second is, these handles are not constant...they are different each time I bring up the dialog box.
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Yes, you are correct, the window handles will most likely be different each time the dialog comes up. Here's a step by step in Spy++ to get the info you need.
1. Bring up the common dialog having the control you want to hide. Do this before you run Spy++.
2. Run Spy++ and press Alt-F3 (Search for window).
3. On the Find Window, there's a crosshair icon, grab it and drag to the control on the common dialog you want info about. If you need to, you can check the "Hide Spy++" checkbox to get Spy++ out of the way. This will show the Handle and class name. Sounds like you got this far.
4. Now, click on the Ok button on the Find window dialog (in Spy++). The window you're wanting info about should now be selected in the tree view on the "Windows 1" view.
5. Right click on the highlighted item in the tree and select properties. This will bring up another dialog with the information that you need, namely the control ID.
Note that the Control ID is displayed in hex.
Given the Control ID, you can do something like this in your subclass OnInitDialog (example hides the Cancel button):
CWnd* pCancelBtn = GetDlgItem(0x0002);
if (pCancelBtn != NULL)
pCancelBtn->ShowWindow(SW_HIDE);
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Thank you so much for the help. You've lead me in the right direction. The problem was in calling the GetDltItem...I needed to call that for the parent window:
CWnd *theParentWnd = this->GetParent();
CWnd *theEditBox;
// edt1 is defined in <dlgs.h>
theEditBox = theParentWnd->GetDlgItem(edt1);
theEditBox->ShowWindow(SW_HIDE);
This worked! By the way, the ID in spy++ matched that defined in dlgs.h, so I just used it.
Thanks again...whew, what a workout!
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