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HI,
u can use typeid operator for checking
for this u have to enable the Run Time Type Identification from Project options.
the following code snippet explain the operation
using dynamic_cast operator also u can accomplish this.
// expre_typeid_Operator.cpp
// compile with: /GR /EHsc
#include <iostream>
#include <typeinfo.h>
class Base {
public:
virtual void vvfunc() {}
};
class Derived : public Base {};
using namespace std;
int main()
{
Derived* pd = new Derived;
Base* pb = pd;
cout << typeid( pb ).name() << endl; //prints "class Base *"
cout << typeid( *pb ).name() << endl; //prints "class Derived"
cout << typeid( pd ).name() << endl; //prints "class Derived *"
cout << typeid( *pd ).name() << endl; //prints "class Derived"
delete pd;
}
-Sarath
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I took a look at the doc. Ok that's fine but some actions need to be performed depending on the type of object. So, you need to compare the result from typeid to something. What will be this something ? Probably getting the class name from the clas info and compare it to a string:
if (strcmp(typeid(MyClass).name(),"CPlayerShip"))
{
}
I don't see really a major advantage on using a technique in which you manage the type of your class yourself (see my previous post). And honnestly, I found that ugly  (but that's personal).
Any comment ? (I just explain my point of vue, I would like to have your  ).
Cédric Moonen
Software developer
Charting control
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You should compare the type_info objects returned by typeid, not the class names.
if ( typeid(myObj) == typeid(CPlayerShip)) {
}
The major advantage over managing the type of class by yourself is that you don't have to manage the class information by yourself
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Ok, I didn't read carefully enough the doc  . I didn't saw that you could pass the class to the typeid (typeid(CPlayerShip)).
In that case that make sense. But I suppose there is also a drawback in enabling RTTI. Do you have any idea about that ?
Cédric Moonen
Software developer
Charting control
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check whether this serve for ur purpose. enable RTTI.
class Base;
class Der: public Base;
class Der1: public Base;
Der * d1 = dynamic_cast<der*>(d); // ok
Base * b1 = dynamic_cast<base*>(d); // OK
Base * b2 = dynamic_cast<der1*>(d); // error
-Sarath
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G_urr_A wrote: I was wondering if there is a way to determine what type of object the pointer is pointing at.
Is the typeid operator of any help?
"The largest fire starts but with the smallest spark." - David Crow
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Well, as earlier posters have pointed out, dynamic_cast and typeid can be used to extract the information you want.
However, to me at least, when you need to do this (and presumably frequently for an astroids game) you might start asking if you have the best possible design.
I kind of liked the suggestion of the eariler poster about adding a function like "virtual bool ResolveColision (baseClass *)". Otherwise you could have a huge ugly mess of collision resolution between any 2 possible object types.
If you happen to just need to be able to get set of all asteroids in the game, why not keep around an extra container just for astroids (and one for ships, missles, etc). Then you can iterate through any specific object without messing with all the other object types you are not interested in.
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I've ended up using typeid now.
And of course I'm using the best possible design. Not.
It's grown slightly too messy for my tastes by now, and it'll probably get worse.
The whole thing is a school project in which I have to cooperate with another guy. We've implemented support in some places for features that haven't been implemented, we did not think everything through before we started writing, and we don't really share a common concept of what OO is, so the code is quite messy. I'd love to rewrite the whole thing, but we're expected to present the stuff to our teacher this friday, and we're expected to understand all the code (he needs to understand "my parts"), and he's out of town, coming back thursday evening. So, a rewrite isn't an option right now.
But, thanks a lot to everyone for the input! We got my problem solved, and I got some other good info on what not to do next time. Now I just need to finnish this stuff...
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Hmm.... Since I've already started a thread, I guess I might as well put it to good use...
I've implemented an ugly hack now.
In the code where I give bullets their position and speed, I first find the ship that fired them in ObjectList (which is the vector of *base_class that I've mentioned), then get some data from the ship object. The thing is, I need to access methods that are specific to the CShip class, but I've only got a pointer to base_class to handle it. What I do now is the following:
CShip *temp;
temp = (CShip*)(void*)ObjectList.at(i);
I cast to void* and then to the data type I need. Anything but this explicit casting produces errors, since the compiler doesn't realize that I've checked (using typeid) that what I'm handling is really a CShip object.
This solution is really ugly, IMO. There should be a good way to do this, but I can't figure it out (I'm kind of new to OO).
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If you must use this technique use dynamic_cast instead. This design is poor: using a downcast is rarely needed and you should use virtual function instead.
Steve
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Hi ppl,
The problem is error #10061 (WSAGetLastError()) with connect() when I am trying to connect to a host that behind a router. I have already port-forwarded it and shut the firewall off, still the host refuses the connection activly. Please help.
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Well, the error says it all...;)
WSAECONNREFUSED
10061 No connection could be made because the target machine actively refused it.
Don't think you are, know you are...
custom hardware & software - olloc.be
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Hi All,
I have a problem in timers....Actually I am using the OnTimer() function for one purpose (say keeping track of the list box added item ...only when some item is added) ....I want to use the same ontimer() for updating the "Current System Time" in the static text control also (where the timer will be always used not like the previous case ).... So is there any way to define two timers for the same dialog ....or anyother alternative..... or can anyone tell me how to use CALLBACK fuction in the setTimer() function for the solution of the same...
Thanks in Advance
With regards
Raja Bose
-- modified at 7:09 Wednesday 17th May, 2006
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Create two timers with different ID. In the OnTimer function, the parameter supplied to the function is the ID of the timer which has 'finished'.
Cédric Moonen
Software developer
Charting control
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Dear Raja,
u will get the value passing to nIDEvent (first parameter) of SetTimer function will receive at OnTimer Function as nIDEvent
so u can differentiate ur functionality through setting diferent event for timer
e.g:
#define UPDATE_LIST 1
#define UPDATE_STATIC 2
#define ELAPSE_TIME 200
// set timer to update list
SetTimer( UPDATE_LIST, ELAPSE_TIME, 0 );
// set timer to update static
SetTimer( STATIC, ELAPSE_TIME, 0 );
At OnTimer function
void OnTimer(UINT nIDEvent)
{
if(UPDATE_LIST == nIDEvent)
//update list
else if(UPDATE_STATIC == nIDEvent)
//update static
}
Hope it is clear
-Sarath
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thank u Sarath ... it was working great ... Thank u for ur king help
With regards
Raja Bose
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Hi out there !
I am currently writing a tab control view that allows for the dynamic appending of other CWnd* based widgets on each tab. On appending, a small header bar is assigned to each widget, which makes the widget collapsible, basically turning the widget into a rollout-like control.
The structure then is as follows :
CTabView (derived from CCtrlView)
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|- CTab (derived from CScrollView)
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|- CTabElement (derived from CWnd*)
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| |- CWnd* widget
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|- CTabElement
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| |- CWnd* widget
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The two things I am most concerned about are :
- Though I create the CTabElements with CTab as its parent, I need to manually call their OnPaint-methods in the OnDraw-Method of my CTab, shouldn't MFC do this automatically ?
- When scrolling sets in I am only able to properly update the original view content, i.e. the part of the screen that shows when the scroll position is (0,0).
Possibly those problems are closely related, but because I am pretty new to MFC, i have not yet managed to find the particalur point where I made the misstake.
Maybe someone can give me a hint,
thanks in advance,
Christian
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Your question is not very clear, but if you want to get the current time, you can use:
CTime Time = CTime::GetCurrentTime();
Cédric Moonen
Software developer
Charting control
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if you need to current time see
<br />
CString str;<br />
SYSTEMTIME st;<br />
GetLocalTime(&st); <br />
<br />
str.Format("%d:%d:%d:",st.wHour,st.wMinute,st.wSecond);<br />
whitesky
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How can I insert the System time(current time) into access like the former
in C++ (eg. 2006-04-19 16:41) ???
The time in access is datetime type!!!
I know in Java , it can use the method getdate().
But I have scanned many meterials , that I can't find in C++
retcode=SQLExecDirect(hstmt,(UCHAR*)"insert into package(Protocol,SrcAddr,DstAddr,SrcPort,DstPort,TotalLen,GetTime)values('a','b','c','d','e',2000000,'3-2-2006')",SQL_NTS);//SQLÓï¾äÖ´Ðгö´í
the quote '3-2-2006' of the sentence , can i substitue with the system
time???
Jeff Fan
No change is the worst!!!
The principal of mine
msn:fyr000000@hotmail.com
If you like coding , add me.
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I am sorry that I have asked by mistake ! I go to the link again!!!
Thank you all very much.
Jeff Fan
No change is the worst!!!
The principal of mine
msn:fyr000000@hotmail.com
If you like coding , add me.
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fyr000000 wrote: http://www.codeguru.com/forum/showthread.php?t=387391[^]
Isn't CodeGuru help you?, any way you can try COLEDateTime.
COleDateTime curTime= COleDateTime::GetCurrentTime( );
CString str = curTime.Format(_T(" %Y-%m-%d %I:%M"));
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
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Ovidiu answered your question very plainly. What's the problem?
"The largest fire starts but with the smallest spark." - David Crow
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Hi,
I need to establish a URL(https://test.com/test/servlet?parameter-list) connection from VC++ through a request object and get a response object in the form of plain text like password changed: ab123 or password not changed: no user. The connection should use a client certificate for a standard http connection.
Can any one point to some API or samples which provide methods for sending https requests and getting back the response(response is text).
thanks
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