C++ :: How To Save Callback Function With Its Parameter And Call It Later
Dec 31, 2013
I 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?
I 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?
While running it gives the runtime error: "Extra parameter in call to factorial."
#include<iostream.h> #include<conio.h> int factorial(long int); void main() { clrscr(); long int a; cout<<"This program displays the factorial of the number you enter."<<endl;
There 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.
Is 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?
My errors are at the end of the program in two function calls within the definition of the InsertByValue function. g++ does not seem to recognize NumArray as a valid parameter.
#include <iostream> #include <assert.h> using namespace std; const int CAPACITY = 20;
/* Displays the content of an int array, both the array and the size of array will be passed as parameters to the function @param array: gives the array to be displayed @param array_size: gives the number of elements in the array */ void DisplayArray (int array[], int array_size);
I 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:
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().
The thing is, when I don't create a prototype of count and straightaway define it before void main() my program runs, but it gives error in this program that "extra parameter in call to count()" But what to do then?
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.
// RemoteControlMonitor.H typedef void (*keyaction)(unsigned int key);
class RemoteControlMonitor { private: keyaction rph; keyaction rrh;
[Code] .....
But I got compile error as below:
RemoteControlMonitor.H:58: invalid type `void *' for default argument to `void (*)(unsigned int)' rcx1.C: In function `void __static_initialization_and_destruction_0(int, int)': rcx1.C:54: ANSI C++ forbids implicit conversion from `void *' in default argument
1st when i fill the things on form then saved in database after saving record when i want add another record it shows an error. after saving it saves new record refresh doesn't work
I am trying to develop a GUI using MFC, but I am having trouble using CFiledialog to save a file. The problem is, the file is not getting saved to the folder when I use the CFiledialog. Below is the code I am using.
I 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?
int *buildTrail(int antIndex, int start, double *pheromones) { int *trail = new int[tabu]; bool *visited = new bool[tabu]; trail[0] = start; visited[start] = true;
[Code] ....
If I comment all lines includes visited word , no exception occurs , Otherwise , exception throws.
Simply put , How can i delete visited parameter as long as its role has been finished? . . . delete visited ; return trail;
Forever, I've passed FILE objects into functions like the first parameter; I've never had an issue reading or writing files using that form - no file errors, no compiler warnings, etc. Recently, I saw the second parameter form, and wondered why that was?
I still don't quite get this part of pointers. What's the second parameter form doing differently than the first when the first version *appears* to work as intended??
Write a program that inputs 10 integers from the console into an array, and removes the duplicate array elements and prints the array. By removing, I mean that you should make it appear as if the elements hadn't been there. You may assume that all the integers are between 0 and 100, Write at least 1 function in addition to the main function, and pass an array into that function as a parameter. e.g.
Please enter your 10 numbers: 1 2 3 4 5 6 7 8 9 10 The array contains: 1 2 3 4 5 6 7 8 9 10
Please enter your 10 numbers: 1 1 3 3 3 6 7 8 9 9 The array contains: 1 3 6 7 8 9
Please enter your 10 numbers: 1 1 1 1 1 1 1 1 1 1 The array contains: 1
The bolded area is where I'm having trouble. How I can go about doing this, passing an array into the function as a parameter?
Here is my code:
#include "stdafx.h" #include <iostream> using namespace std; int main () { const int MAX = 10; int a[MAX] = {0}; int i;
Pseudocode: template<typename T /*, some parameter for member_function */> class Foo { public: void someFunction() { T t; t.member_fuction(...); } }
I'm trying to make the call to T::member_function a templated value because member_function might vary by name in my scenario. Since std::mem_fn isn't a 'type', i can't do something like Foo<std::string, std::mem_fn(&std::string::clear)> foo;
I also want to take into account that member_function might have more than one parameter. That is, the first parameter will always be something known but there might be other defaulted parameters.
The only thing I can think of is to make a proxy structure, something like this:
#include <iostream> #include <initializer_list> using namespace std; void doSomething(std::initializer_list<int> list) { } int main() { doSomething({2,3,6,8}); return 0; }
I write a small piece of code like above. But I can not compile it successfully. I try it both with and without the line "using namespace std", but nothing worked.
The error list: Symbol 'initializer_list' could not be resolved
