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OmarSH wrote:
1>stdafx.obj : error LNK2019: unresolved external symbol "public:
__thiscall list::~list(void)" (??1list@@QAE@XZ) referenced in function _main
Is the list object being referenced yours or the one from the STL? If the former, it's missing a destructor.
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"Show me a community that obeys the Ten Commandments and I'll show you a less crowded prison system." - Anonymous
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Hi all,
I ask me of myzelf what kind of Timers APi can I use for create an delays of microseconds?
I read the MSDN site and I found the topics of different manners for create function that generates an delay of microseconds.
Witch one is the best solution for my problem if the user set the delay in microseconds and the function executes the adjustable microseconds of the user.
I hope that here developers knowledge the WinAPI and low level programming. I work under Windows XP/7
We have the chooice of:
1 Multimedia Timer
2. Waitable Timer
3. Queue Timer
1) Whitch is the best chooice of this timers?
2) How can I rewrite the code for use in microseconds?
3) I wish to change in the exists functions (see above) for programming the functions that using the microsecond
(delay) timer. I don't know how I can change this in the code:
DECLARE SUB TimeInit_us()
DECLARE FUNCTION TimeRead_us() AS QUAD
DECLARE SUB Delay_us(BYVAL wDelay AS WORD)
'------------------------------------------------------------------------------
' TIME functions
'------------------------------------------------------------------------------
' This set of functions is important for various time measurements. Just as
' with DELAY function (in ms) and Delay_us (in µs), TIME functions also operate on millisecond or
' microsecond basis.
' TIMEINIT (in ms) and TIMEINIT_US (in µs) will reset the timers to zero and start them again
' with ms or us precision
' TIMEREAD (in ms) and TIMEREAD_US (in µs) functions will read the amount of time (in ms or us)
' since the last TIMEINIT or TIMEINITUS function was executed. Both functions
' return a 64-bit integer
4) How can I combine it to an Quad word (64 bit)?
[code]
#Dim All
#Include "Win32API.inc"
Type LARGE_INTEGER
low_part As Long
high_part As Long
End Type
Global g_TimeUnit As Double
Global g_Start_Time_Low As Long
Global g_Start_Time_High As Long
'========================================================================='
'Milliseconds Delay Timer Functions '
'========================================================================='
Sub TimeInit()
'==============================================='
'Reset the milliseconds Timer to Zero
'will reset the timers to zero and start them again with ms precision
'===============================================
Local f As LARGE_INTEGER
Local t As LARGE_INTEGER
Local x As Dword
x = QueryPerformanceFrequency(f)
g_TimeUnit = 1000 / f.low_part
x = QueryPerformanceCounter(t)
g_Start_Time_Low = t.low_part
g_Start_Time_High = t.high_part
End Sub
Function TimeRead() As QUAD
'=======================================
' TIMEREAD functions will read the amount of time (in ms)
' since the last TIMEINIT function was executed. The function
' return a 64-bit integer
'=======================================
Local t As LARGE_INTEGER
Local x As Dword
If(g_TimeUnit = 0) Then g_TimeUnit = 0.000838096515
x = QueryPerformanceCounter(t)
Function = (t.high_part * 4294967296# + t.low_part - g_Start_Time_High * 4294967296# - g_Start_Time_Low * g_TimeUnit)
End Function
Sub Delay(ByVal wDelay_time As Word)
'=============================================
'With the DELAY function is important for various time measurements. Just
'as with Delay function, Time function also operate on ms basic
'=============================================
Local time_start As Double
time_start = TimeRead()
While(TimeRead() < (time_start + wDelay_time)) : Wend
End Sub
[/code]
I hope that here someone help me but I can't written the functions for the microseconds timer
Kind regards
Stephane
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Which programming language do you want help with?
Remove your VB code if you now want help with C/C++, or delete your message.
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C and MFC without classes. I think C is without classes.
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You did understand what you were told in VB forum?
Windows will interrupt your code whether you want it to or not. That is what is meant by 'pre-emptive' Operating System.
The windows scheduler has a resolution of about 15ms and it will mess up all attempts to get reliable timing shorter than what the scheduler has. Believe me this is not a trivial task. see here.
I also prefer to use the following method..
"If you do a Sleep(), you might hope that when you regain control you are probably pretty soon after a clock tick. So assume that, reading the counter immediately after a Sleep(), and repeat several times, taking the earliest counter value recorded to be the counter value at the tick. This method will have a small but hopefully constant offset; it's the best we can do, at least in user space (more may be possible as a driver, using the DDK KeQuery* functions; we haven't investigated this)."
I just average a counter over several milliseconds (less than the quantum of the scheduler's 15ms) and divide it by 1,000 or 1,000,000 to get a rough sub-ms delay. Not ideal but it obtains a reliable value when the NT scheduler is running.
there is some downloadable C source code from the following link.
www.lochan.org/2005/keith-cl/useful/win32time.html
modified 10-May-13 17:45pm.
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The windows timer has a granularity of about 10 or so milliseconds, so unless you create your own HW that interrupts every few micro seconds, in which case you will kill system performance, the only solution is s dead loop count.
Of course if your thread get descheduled, and it will be by kernel code even if you give it a high priority, then your timing will be off, but it might give you enough accuracy.
==============================
Nothing to say.
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hello everybody :
anyway i am working on program that use alot of object
if i want to compare in (if statement) like
if(ob.x==ob1.x)
if(ob.x != ob1.x) do i need to overload these operators or not (because visual studio says no operator match ,
if yes could you tell me the code with simple explain
thanks anyway .
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Assuming x is an object of type X, you will need to overload the == and != operators in class X.
class X
{
bool operator ==(const X& rhs)
{
return this.var == rhs.var ? true : false;
}
bool operator !=(const X& rhs)
{
return this.var == rhs.var ? false : true;
}
};
The comparison logic would really depend on your particular business case.
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an if X where object from struct not from class ,will the use of this be true????
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struct and class are the same in C++.
Only difference is that, by default, class members are private and struct members are public.
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but there is problem :
this .x
x is a member in struct not in class , and the hole struct is a private member of class
and the overload i need it for object of struct , not the class,
so that compiler tel me that x is not a member of class,
( error class y has no member x,
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Overload the operators inside the struct.
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Hello,
I cannot find IACLCustomMRU in any header.
Same thing for associated constant : IID_IACLCustomMRU
Thanks in advance.
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Find what ?!
There is nothing in MSDN doc about declarations, include files, IID_IACLCustomMRU
constant, etc ...
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I guess you need to ask Microsoft.
Use the best guess
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hello every body:
i made some java courses last years , i found that i can make a GUI by includeing some library , like import " javax.swing "
anyway this is just in java, i want to ask is there anything like that in C++ , as java is close to C++,
if there is i want to tell me how to do something like that i visual studio ,and if you know some resource i will be happy if you share it ,
thanks
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OmarSH wrote: ...as java is close to C++...
They are similar in syntax only, nothing else.
OmarSH wrote: if there is i want to tell me how to do something like that i visual studio
If you have VS installed, just click the Create button. In the "New Project" dialog, select something under Visual C++ like MFC or Win32.
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"Show me a community that obeys the Ten Commandments and I'll show you a less crowded prison system." - Anonymous
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Pure C++ does not support creating GUIs.
C++ is meant for creating optimized, reusable libraries.
However, you can use some frameworks or libraries that are based on C++ like MFC as David mentioned.
This would, however, be OS dependent.
Some libraries like QT[^] provide source code compatibility between OSs where you write code once and build the same code on different environments.
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«_Superman_» wrote: Pure C++ does not support creating GUIs.
C++ is meant for creating optimized, reusable libraries.
Really? I wonder how I've neen doing it all these years then?
Use the best guess
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Richard MacCutchan wrote: Really? I wonder how I've neen doing it all these years then?
might be late!!... you might be writing executable in disguise of library 
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
Never mind - my own stupidity is the source of every "problem" - Mixture
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and You
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Hi, I placed bitmap file and source code in same folder.
I use:
hBitmap = SHLoadDIBitmap(_T(".\zzz01.bmp"));
try to load the bit map, but it can't load it.
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That's probably because the executable program does not get written to the same folder as the source code. Your bitmap should be copied to the Debug or Release folder in the solution directory.
Use the best guess
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econy wrote:
hBitmap = SHLoadDIBitmap(_T(".\zzz01.bmp"));
You are using a relative path. If you just want to find out if your "load" code works, use an absolute path instead. If that works, then you can study the difference between the two.
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"Show me a community that obeys the Ten Commandments and I'll show you a less crowded prison system." - Anonymous
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