C++ :: How To Add / Delete Object Dynamically Run Time
Nov 27, 2014How to add/delete object dynamically run time ?? I have a question in which i need to add/delete object dynamically dynamically how to do it ??
View 2 RepliesHow to add/delete object dynamically run time ?? I have a question in which i need to add/delete object dynamically dynamically how to do it ??
View 2 RepliesI'm dynamically creating some labels. This code creates them OK.
panel1.Controls.Clear();
for (int i = 0; i < 5; i++) {
Label label = new Label();
label.Top = (30 * i) + 20;
[Code] ....
Now, after I'm done with them, I'd like to delete them but my code below skips each of the two forloops, so nothing happens. The labels are still on my form. When I debug into this code, I stop on the first forloop and then I step but the flow never goes into the forloop. It jumps to the next forloop where the same thing happens.
List<Label> itemsToRemove = new List<Label>();
foreach (Label label in Controls.OfType<Label>()) {
if (label.Tag != null) {
[code]....
I am working on a project, where I have to be able to exclude some code fast and dynamicly at compiletime.
I got a scheduler running and actually I just want to remove some of the tasks from it - but at compile time so that the code wont take up space in my microcontroller.
I know that I can use macros like #ifdef #endif etc. But I think that method makes the code unreadable and complicated.
How to archive such functionality a more elegant way?
I am to first increment data members of object that has not created dynamically (i have done with this part),now i have created object dynamically and how to increment its data which i have passed as argument as:
obj3 = new manage(35 , 36)
int NextPixel(int antIndex, int currentPixel , Ant *ant , IplImage *edgeImg) {
int left = currentPixel - 1 ;
int right = currentPixel + 1 ;
int up = currentPixel - edgeImg->widthStep ;
int down = currentPixel + edgeImg->widthStep ;
[[Code] ....
if those lines are uncommented , program gives heap error.Why?
I have this class I have been working with,
Code:
// objects to hold results, row id, and name
class result_holder {
public:
// initialize class members
result_holder() : row_id(0), row_value(0.0), row_name("") { }
[Code] ....
There are cases where I need to find an object based on the value of row_id and delete the object from the vector row_results. I could find the proper object by looping through the vector and testing against each member.
Code:
// id I am looking for
unsigned int id_to_delete = 12;
for(i=0; i<row_results.size(); i++) {
if(id_to_delete == row_results[i].row_id) {
delete row_results[i];
}
}
I have used find before to find the position in a vector with a specific value, but I don't know how to use find to locate a specific value for an object member.
Also, is delete what I need to get rid of the object or should I be using erase as in,
Code:
// id I am looking for
unsigned int id_to_delete = 12;
for(i=0; i<row_results.size(); i++) {
if(id_to_delete == row_results[i].row_id) {
row_results.erase(row_results.begin()+i);
}
}
I have to delete an object at a time that I don't know it's held by another thread(s) or not. For example
static void foo(CLASS* ref){
pthread_mutex_lock(&l);//[POINT-A]
//using ref
//do something thread safe
pthread_mutex_unlock(&l);
delete ref;// how can I find out there is no any thread held at [POINT-A]
}
I have to manage a Clinic. I need to delete a booking (for example, if John said he's coming on March 22nd at 15:30 but then he say he's not going to come, I have to delete that booking so another person can use it).
idSearched: the id of the person that is not going to come. I have a lot of specialties and each one has a list. So I ask for the speciality to delete the node (the node contains John's booking). If I don't find it, I return (-1). searchSpecByID return a pointer to the list where the speciality is. So head will point to the first node of the list. In nodeToDelete I have the node I want to delete.
The program detects OK when is the first in the list and when not, but it doesn't delete the node.
Code:
typedef struct bookingList{
tSpecialty specialty;
struct nodo* intro;
} tList;
[Code].....
This is a round robin execution. with gantt chart. arrival time and burst time. I think there is an error in my formula to get the right answer,i cant resolve it but my program is running. What is the code or the right formula??
#include<stdio.h>
int main(){
int i,j=0,n,time,remain,flag=0,ts;
int sum_wait=0,sum_turnaround=0,at[10],bt[10],rt[10];
int ganttP[50],ganttStartTime[50];
printf("Enter no of Processes : ");
scanf("%d",&n);
remain=n;
[Code] ....
So I'm trying to learn how to use time for time based movement and what not. I did this only knowing the command time(&variable)
time_t timer;
int I, X;
void main() {
time(&timer);
X=timer;
while(I==5) {
[Code] ......
There's probably some other better way to do it... Obviously but for now I see it as putting current time in X.
start while
take in time constantly until I is 5
constantly asking is time>X(preset time 5 seconds ahead)
if it is
display message and add one to I
Why doesn't this display my message after 5 seconds?
will copy constructor does object initialization using another already created object? I understand that it can be applied for object initialization and not for assignment.Is it correct?
View 10 Replies View RelatedI have a method to take a Tile object and make an instances of it based on some data from the original object. Than it is suppose to manipulate the a specific instance and save the results. The first loop through it works but it changes all instance as well as the base.
public static int recurse(int count, Tile[,] b,Huristic h,int check) {
if (check==1) {
boardState.Add(B)/>;
return check;
} if (check == 0)
[Code] .....
#include "B.h"
class A {
public :
A()
{
s_b = new B();
b = new B();
[Code] ....
In my project i have seen static object as above . But not able to know what is the exact use of it and how they are different from general object .
a function returns a temporary object like
int myfun(){
int x = 0;
return x;
}
this function will return a temporary integer now void fun1(const int & num); this function can receive from myfun().BUT void fun2(int & num); this function cannot receive from myfun() Why is that, Moreover what is lifetime of a temporary object like one returned in myfun() ???
I am trying to use web api in order to return custom json response keys. For this i have return a custom class to return json response
Custom Class:
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
[Code].....
I have a combobox with Items 1024
2048
4096
8192
String cach = form.comboCache.SelectedItem.ToString();
I am using the above code to retrive an item selected by user,But this line is giving an exception "Null Reference Exception, Object reference not set to an instance of an object"
I am using session to pass object from controller to custom class in MVC Web API. here is my code, i am getting error at session.
public HttpResponseMessage Get()
{
var person = db.Persons.ToList();
[Code]....
In Visual Studio 2010 C++
I have a series of existing text objects
The text properties names are
item1_lbl,
item2_lbl,
item3_lbl,
….
Based on a selection I want to change an object. I generate the name of the object I want to change in a string so from this string is there a way to get a pointer to the correct text object that is same name?
make a time-in time-out fuction which extracts the no. of hours and minutes from a string entered by the user.
#include <iostream>
#include <fstream>
#include <string>
[Code].....
when we would use add items at design time and when we would add them at run time
does it have anything to do with the page load method? if so, can i type this in source code instead?
I'm trying to figure out how I can create a vertex array object at offset of a vertex buffer object.I've created the buffer object. I'd like the "texs" idnex data to start at the texture coordinate content of the vertex_t structure.
Type definitions:
struct vertex_t {
vector3d_t position;
float s; // Texture coordinate s
float t; // Texture coordinate t
};
Code so far:
// How do I make this start at a certain spot of the VBO?!
glVertexAttribPointer(texs, 2, GL_FLOAT, GL_FALSE, sizeof(vector3d_t), nullptr;
//...
I have array of pointers and when i tried to assign values dynamically all array items have the same value which is last value.
char* list[];
int DynamicDemo(void)
{
[Code].....
Consider the following:
Code:
int *p;
p = new int[5];
for(int i=0;i<5;i++)
*(p+i)=i;
Now suppose we want to add a 6th element (without using vector)
One way is to copy it across to a larger array:
Code:
int *p;
p = new int[5];
for(int i=0;i<5;i++)
*(p+i)=i;
// realloc
int* temp = new int[6];
std::copy(p, p + 5, temp);
delete [] p;
p = temp;
This looks like a very expensive operation and im looking for other ways.
Three questions regarding the above: Not using vector, is this the best way to do this?What about using realloc? How would I use realloc in this situation?Any other ways apart from realloc or vector?
I have created a database for music cds:
Code:
#include<stdio.h>
#include<stdlib.h>
#define array
typedef struct cd_database
[Code]....
When I am using malloc instead of arrays the code is not working properly after exit. I have tried alot but can't came up with a way
I would like to realloc a 2D array. I have a counter, itime, it increases each step. Each step, I would like to reallocate my array, keeping the old values, and add new values to the array. When itime=1, I use only malloc, because it is allocated for the first time. When itime increases (e.q. itime=2), realloc comes into process. In the realloc process the GUI crashes.
int itime;
char ** solpointer;
itime = 1;
do {
if( itime == 1 ) {
solpointer = (char**)malloc(sizeof(char*) * itime);
solpointer[itime-1] = (char*)malloc(sizeof(char) * 32);
[code]....
I've recently integrated a scripting functionality into my game engine (squirrel), but I can't figure out how to dynamically link the library.I have to dynamically link some libraries for licencing sake, but I'm forced to statically link Squirrel. How can I statically link Squirrel, but dynamically link the others?
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