C++ :: Why To Say Function As Callback
Jan 19, 2015Why do we say function as Callback?what does a call back mean?
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C++ :: Writing To File In Callback Function
Mar 31, 2013I want to do a basic thing but for some strange reason there is something not working.
I need to write to a file but I'm handling all the code in a callback function, which in turn is declared in a class. Here is the architecture of my code:
Code:
int main (int argc, char **argv) {
ImageConverter Aclass;
while(1); //infinite loop
return 0;
[Code] ....
But this doesn't work, the file gets created but it allways overwrites itself which is not what I need to do.
What I am doing wrong? Is it because i am constantly declaring outfile?
C++ :: ROS Subscriber Callback As Member Function Does Not Get Called
Feb 27, 2015There is already a thread with exactly the same problem I have, but the answer to solve the problem isn't stated at the end. Problem with callback as classmember.
View 4 Replies View RelatedC++ :: How To Save Callback Function With Its Parameter And Call It Later
Dec 31, 2013I have a function (name Callback), with take some parameter( name Arg). I want to create it before, pass it to other class ( class B). And in class B, call the Callback function with Arg paramater. It's something like this:
class A {
void A::doSomething(int a, bool b){//dosomething};
void A::setCallback(B b) {//I don't know how to do this};
[Code].....
How can i do this? And what happen with I want B can get more type of callback function, which mean I don't know the type of Callback's paramater?
Visual C++ :: Reading NFC Device - Callback Function?
Jan 7, 2015Is it possible to read NFC card reader in VC++/MFC. Is it possible to develop a callback function that will read the NFC device, and see once the card is inserted, it takes that value from the card and store it in a DB?
View 3 Replies View RelatedC++ :: Extension DLL Callback Function Used For A Windows Service And Write To File
Oct 11, 2014I have a problem with an extension DLL that has an exported function. The function is being exported ok, it is called by a Windows service. The Windows service is using the exported function, and everything works. I am trying to create a file with:
ofstream file;
file.open("C:dir ofile", ios:ut);
file << "text";
But nothing happnes however. There are no errors, the file is just not created. Also, if i try to call MessageBox() in the exported function, nothing happens as well . I have a .h file which exports the function with __declspec(dllexport) DWORD WINAPI functionName(), and also a .cpp file with the function definition. There is no main().
C++ :: Callback For A Button?
Apr 25, 2013I have made a calendar that looks similar to Outlook, and I have the next/previous buttons, but they don't do anything when you click them. how to create the callback so that when I click next it goes to the next month?
View 4 Replies View RelatedC :: How To Emulate Callback Mechanism - Pthreads Join
Jun 19, 2013I am trying to emulate callback mechanism in C. The code I have is follows:
Code:
#include <stdio.h>
#include <pthread.h>
struct fopen_struct {
char *filename;
char *mode;
void *(*callback) (FILE *);
[Code] .....
If I do a pthread_join in fopen_t() it works perfectly fine. But if I do that in main() I get a segmentation fault error. I want to call it in main() because I want it to be non-blocking, is there any solution?
C# :: WCF Duplex Service Callback Channel Hanging
Jul 1, 2014I have an application based around a WCF Duplex service. I have problems when the user "Restarts" the work the application does... under the hood, the client side closes the connection to the WCF service and creates another. The Service contract is defined like so...
[ServiceContract(Namespace="net.tcp://namespace.MyService",
SessionMode=SessionMode.Required,
CallbackContract=typeof(IServiceCallback))]
public interface IMyService {
[OperationContract(IsOneWay=true)]
[Code] ....
The issue I see is that the _context.Close() call always times out and throws an exception. Although I'm then aborting the channel, this feels wrong to me, and I believe it's the cause of freezing in my application. Why the Close() call fails?
I missed something earlier regarding my callback implementation that might be relevant. It looks something like this:
[Callbackbehavior(ConcurrencyMode = ConcurrencyMode.Single,
UseSynchronizationContext = false,
IncludeExceptionDetailInFaults = true)]
public class CallbackImplementation : IServiceCallback {
public void SendMessage(string message){
// Do something with the message
} }
The exception message is "The ServiceHost close operation timed out after 00:00:30. This could be because a client failed to close a sessionful channel within the required time. The time allotted to this operation may have been a portion of a longer timeout.". There's no inner exception.
The big problem is that the client application freezes when the main application process is started after one client has been disposed and a new one created. I've also noticed that when you close the WPF application, it doesn't close properly and keeps running in the background, preveting you from starting a new instance.
Visual C++ :: User Callback And CResource Exception
Oct 8, 2014In my Project, I'm using my Parent Dialog(TestDlg) as a background dialog.
Child Dialog 1 = Main.cpp & Child Dialog 2 = Dummy.cpp
1. I like to call both dialog continuously one by one.
Using Timer function i called continuously the dialogs.
After 5 minutes getting an error, "0xC000041D An unhanded Exception was encountered during a User Callback".
2. Then, I'm using CGdiPlusBitmap.cpp file to load PNG image into buttons.
After 5 minutes getting an error - "CResource Exception".
For reference test code attached.
C++ :: Syntax Error In Function Call - Type Mismatch In Parameter In Function Sort
Jul 6, 2014error says "cannot convert 'int*' to 'int' in function main()
and also
type mismatch in parameter in function sort(int,int)
Heres the code:
#include<iostream.h>
#include<conio.h>
void main() {
void sort(int,int);
clrscr();
[Code] .....
C :: Function That Will Work For Both Dynamic And Static Implementations Of A Function To Get Transverse Of Matrix
Feb 11, 2013i need a function that will work for both dynamic and static implementations of a function to get the transverse of a matrix. so far, i have this
Code:
matrix transpose(matrix m)
{
int row, col;
row = m.com_dim;
col= m.row_dim;
}
[code]....
this works well with my static implementation, but when i try it in dynamic it gives me errors. the function has to be the same for both dynamic and static implementation
C++ :: Keyboard Function That Is Called In Main Function To Make Shape Move
Jan 19, 2013Ok so I am working on a game and I'm in the process of developing my Player class. Anyways, what I have is a keyboard function that is called in my main function to make a shape move.
void myKeyboardFunction(unsigned char key, int x, int y) {
switch ( key ) {
[Code].....
But when I try to call it, trying to copy my previous method,
glutKeyboardFunc(Player1.playerControls);
I get an error
error C3867: 'Player::playerControls': function call missing argument list; use '&Player::playerControls' to create a pointer to member
I get an error saying it can't convert parameters. I would just like to understand why the arguments become a problem when I make the function a member of my class, when the first method I used is so easy.
Visual C++ :: Error C3867 Function Call Missing Argument List For Calling Thread Function
Mar 19, 2013I searched the web for error: C3867... and the discussions where murky or obscure.
My code excerpt is:
#pragma once
#include <windows.h>
#include <stdlib.h>
#include <process.h>
void PutUpfrmIO(void *);
namespace WordParsor {
[Code] .....
I get the generic message:
error C3867: 'WordParsor::Form1::PutUpfrmIO': function call missing argument list; use '&WordParsor::Form1::PutUpfrmIO' to create a pointer to memberc:userskingc++wordparsorwordparsorForm1.h... and the suggestion fix generate another error.
One person suggested the gcroot<> object wrapper... but I do not know how to modify/declair the function or its argument type.
C :: Reverse Function That Inserts And Prints Binary Function Correctly
Nov 3, 2013I have written a function that inserts and prints a binary function correctly.
For example a tree like this [URL] ..... would print like this
Code:
node: 10
node: 7
node: 6
node: 8
node: 9
[Code] ....
Here is my print function
Code:
void prt_tree(struct node *tree) {
if (tree == NULL) {
printf("Null Tree
");
return;
[Code] .....
Could I just make some adjustments to my function to reverse it? and if so, how?
C++ :: Pass 2 Arrays Into Void Function And Return Values To One Function?
Feb 12, 2014I'm trying to pass 2 arrays into a void funtion, and return values to one function.
this is the the program I'm working with, after I'm done I have to split it into 3 files, a header, a main, and a separate cpp file for the functions to live in.
#include <iostream>
using namespace std;
void processArrary(int numberCount[], int Numbers[], int intnumberSize, int numberCountSize);
int main() {
int Scores[26] = {76, 89, 150, 135, 200, 76, 12, 100, 150, 28, 178, 189, 167, 200, 175, 150, 87, 99, 129, 149, 176, 200, 87, 35, 157, 189};
int numberCount[8] = { 0 };
[code]...
The goal of this program is to separate and count the groups of numbers then output the amount of numbers in each group. Near as I can tell, everthing should work, but I'm getting all zeros to be displayed in each group.
C :: Main Function Does Not Return Any Values When Calling Other Function?
Jun 9, 2013The function is supposed to return value from the file in my main, but I am getting empty value. I am trying to get better with pointer. Right now just teaching myself.
right now the only way for this code to show value is when in put the putchar(*ps) inside my readfile function. I would like to readfile to return value and print in the main function.
Code:
#include <stdio.h>
char *readfile(char filename[]);
int main(int argc, char *argv[] ) {
[Code].....
C++ :: Calling Base Function From Derived Overloaded Function
Nov 10, 2014Here is a sample of my question
class Base{
public:
int getNum();
private:
int numToGet;
}
class Derived: public Base {
public:
friend ostream& operator<<(ostream& output, const Derived &B);
[Code]...
C++ :: Passing 2 Dimensional Array Through Median Function To One Of 2 Other Function
Aug 20, 2013I want to use one median function "selectfunction" to choose one of the 2 other functions at random to pass my 2-dim array to the selected function. There is a problem in the median function
#include <iostream>
#define random(x)(rand()%x) // for random number between numbers of 0 and 1
using namespace std;
void proc1 (int iArray[][2]);
void proc2 (int iArray[][2]);
void selectfunction(int iArray[][2]);
int A[4][2] = {{1, 2} , {3, 4} , { 5, 7} , {8, 1} };
[Code]...
C++ :: Using Template Function Inside Class In Separate Function?
Mar 26, 2014i want to use a class to print data stored as vector or array with different data types. i also want the print function two take more than one vector or array or combination of both so that they can be written to file as two columns. so i wrote the following class:
right now it has only one member function for printing two vectors. later i'll add additional functions as required.
note: there has to be template functions inside the class
i also want the object to be global so that i need not pass it as an argument to other calling functions
class printdata
{
public:
template<typename T1,typename T2>
void SaveData( vector<T1> &data1,vector<T2> &data2, std::string var)
{
[Code]....
then i want to call this template function in another ordinary function written in a seperate cpp file
these function declarations are put in a header file. so i need know whether i should put the declaration of the template function in the header to use the function in different functions
C++ :: Calling Function By Sending Char Text Of Function Name
Feb 19, 2014Is this possible?
int myfunc( int a, int b, char * c )
char a = "(int)myfunc()";
char b = "(int,int,char*)"
call(a, b, ...) // Function name and return type, params
I want to do function what registers forward what will get callback if the time is right. Basically then i dont need to edit and add extra functions into source files. I just have to include header and use register forward function. If there is anything close to this it would be perfect!
C/C++ :: Using Template Function Inside A Class In Separate Function?
Mar 26, 2014i want to use a class to print data stored as vector or array with different data types.
i also want the print function two take more than one vector or array or combination of both so that they can be written to file as two columns.so i wrote the following class:
right now it has only one member function for printing two vectors. later i'll add additional functions as required.
note: there has to be template functions inside the class / i also want the object to be global so that i need not pass it as an argument to other calling functions
class printdata {
public:
template<typename T1,typename T2>
void SaveData( vector<T1> &data1,vector<T2> &data2, std::string var){
std::ofstream myfile;
std::string filename;
[code].....
then i want to call this template function in another ordinary function written in a seperate cpp file these function declarations are put in a header file. so i need know whether i should put the declaration of the template function in the header to use the function in different functions.
C/C++ :: How To Hook Function From Same Process And Get Address Of Caller Function
Apr 27, 2013I need to do it to avoid calling a function of my process from injected code.
So would like to hook this function to check whether the call is from the current module or it is from an external module, then I compare the address of the instruction who did the call with the module address range.
C++ :: Retrieving File Object From Function Then Pass To Another Function?
Jun 27, 2014I would like to have 2 functions. (FYI, I haven't even tested these because I don't have a compiler on this PC, so don't know what they'll do. I'm also new to C++, self-teaching.)
My question is, I'm sure that oFile should be type object (of some sort), not int, but I'm not sure how to reference it correctly so that it passes from FileOpen to main to FileClose.
Code:
#include <iostream> //I/O
using namespace std;
#include <fstream> //files
using namespace ios;
int FileOpen(string fileName) {
ifstream oFile (fileName); //attempt to open file
[Code] ....
C :: Function Name To Wrap Standard Strncpy Function
Nov 5, 2014I need a function like strncpy; but, want to be sure the destination ends with a ASCII nul char.
So, I wonder what name is used by others in this case.
I have found strlcpy and it looks like a good name choice. [URL] ....
C :: How To Pass Main Function Argument To Some Other Function
Dec 26, 2014I am writing a program in which a Fucntion has to be wriiten to parse the Command Line . When I include Code for parsing in main fuction iteslf ,its run ok . But I want to make a fucntion of that code and call it from main ,than it show Segmentation error .
By using Debugging I found Some thing is mess with " -m" Parameter of Command line , But Cant Rectify it ..
Code:
int main (int argc, char *argv[]){
//get_parameter_value(argc,argv);
// buffer[packet_size+1]= char ("'");
while (argc > 1) {
if (argv[h][0] == '-')
[Code] .....