C/C++ :: Pointer Value Not Getting Updated
Mar 25, 2014This is the code i have:
Spoiler
#include <iostream>
using namespace std;
class Node {
private:
int value;
Node* left;
Node* right;
[Code] .....
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C++ :: Show Percentage When File Is Being Updated
Jun 19, 2014I want to update a file but I want to show the percentage when it is being updated. How can I do this? Do I need to use threads?
View 2 Replies View RelatedC++ :: Access Variable Updated In One To Another CPP File?
Dec 18, 2012I have two cpp files.I m updating a value of an integer in one cpp file and i want to perform a specific function in the second file as per to the value updated in the first file. ie I m initialing the variable in the constructor. I have two buttons in the first cpp file. On clicking the first button I m updating the variable as 1 and on pressing button two , I m updating the variable as 2. I m retrieving this variable in the second cpp file with respect to the object created for the class in the first cpp file.
The problem is that i m not able tot retrieve the updated value in the second file. only the initialized value is being retrieved. neither 1 nor 2 is updated.
C/C++ :: (OpenGL) Drawing Not Updated When There Is Conditional In Code
Aug 1, 2014I'm making a program to draw a trajectory, was using as a basis the tangent, but when I put 90 degrees, the tangent is very large, so I thought of putting an if (angle == 90) did not use the tangent.
the design is right, but after choosing it 90 degrees it stops to draw.
for example
1-30 degrees - draws
2-45 degrees ---- draws
3 draws -90 degrees ---
4-60 degrees --- not drawing
5 --- 80 degrees --- not drawing
*
*
making routine design is presented below:
void Draw() {
glColor3f(1.0, 1.0, 1.0);
glBegin(GL_LINES);
convert(graus);
if (ant){
x=xx;
y=yy;
[code]....
C Sharp :: Data Is Not Getting Updated In Dropdownlist Using Dataset
Nov 26, 2013Data is not getting updated in dropdownlist using data set:
protected void SpecificationNameDropDownList_SelectedIndexChanged(object sender, EventArgs e) {
if (SpecificationNameDropDownList.SelectedItem.Text != null) {
SpecificationValueLabel.Visible = true;
SpecificationValueDropDownList.Visible = true;
[code].....
C Sharp :: Datagridview And Listview Refresh After Data Getting Updated
Jan 9, 2013 //user list view
da = new SqlDataAdapter("SELECT * FROM [user]", con);
DataTable t = new DataTable();
ds = new DataSet();
da.Fill(ds);
t = ds.Tables[0];
listView1.View = View.Details;
[Code] ....
I tried with datagridview.refresh, update but its not working can any body sugesst me what to do for refresing the data ....do timer we have to use..? if yes then how ...?
Visual C++ :: Use CEdit Control Variable Updated From Tab To Dialog Box?
Jun 24, 2014I have one Tab called Tab4 and one main dialog box called CGrabDlg. The values of my variables are not updated when I change them.?
Here my constructor of my Tab :
Code:
CTab4::CTab4(CWnd* pParent /*=NULL*/)
: CDialogEx(CTab4::IDD, pParent )
, iFilter1(_T("F1_350"))
[Code]....
Visual C++ :: CMFCComboBoxButton - Force Redraw Of Control To Show Updated Selection Via View
May 13, 2015I have a CMFCToolbar containing a CMFCComboBoxButton which needs to be updated via a view. The view correctly updates the selection of the ComboBoxButton however the edit window is not updated until the control receives the focus or the entire window is redrawn.
How can I force the redrawing of the control to show the updated selection via the view
TextEditView::OnUpdateFontBox(CCmdUI *pCmdUI) routine?
C++ :: Linked List Node Passed As Parameter / Argument Pointer To Pointer Notation
Jan 17, 2014I was having problems changing the value of my head node I passed it as an argument as head which would be the address. The parameter was defined as struct node *head. like this
bool deleteNode(struct node *head, struct node *delptr)
I tried manipultaing pointer values to change head node value but it did not work. I saw some code online which used pointer to pointers(in code below) to change head node value it worked I dont fully understand why. Would like better understanding of why.
Would also like to know why the argument call needed &head instead of just head.
remove = deleteNode(&head,found); opposed to remove = deleteNode(head,found);
#include "stdafx.h"
#include<iostream>
struct node{
[Code].....
C++ :: Calling Defined Function Pointer From Another Pointer To Class Object?
Aug 19, 2014I am attempting to implement function pointers and I am having a bit of a problem.
See the code example below; what I want to be able to do is call a function pointer from another pointer.
I'll admit that I may not be explaining this 100% correct but I am trying to implement the code inside the main function below.
class MainObject;
class SecondaryObject;
class SecondaryObject {
public:
[Code]....
C :: Print Pascal Triangle And Stores It In A Pointer To A Pointer
Nov 27, 2013I have to write a program to print pascals triangle and stores it in a pointer to a pointer , which I am not entirely sure how to do. I also have to write the file and read it, then create a binary file. Assignment is attached. I am not the best with programming and especially with pointers. I will post my code below.
Code:
#include <stdio.h>
#include <stdlib.h>
void writePascalTriangle(char *fileName, int heightOfTriangle, int **triangle) {
FILE *fp;
fp=fopen("writePascalTriangle.txt", "w");
[Code] ....
C++ :: Get Pointer That Iterator Points To And Store In Pointer Variable?
Apr 19, 2014I'm making a system like twitter for class called ShoutOut.com I want to be able to get the PublicShoutOut pointer pointed to by the start iterator and assign it to firstShoutOutToDisplay and secondShoutOutToDisplay because I need that in order to pass the pointers to one of my functions. When I step through the debugger the values in start are all default values like "" and so are the values in this->firstShoutOutToDisplay but the message that start points to is being output just fine.
EDIT: got rid of irrelevant code. Am I using the correct syntax to do this?
if (start != finish) {
//getting these because a shoutout needs to be passed to the function that displays
//options for a shoutout
this->firstShoutoutToDisplay = (*start);
[Code] ....
C++ :: How To Convert Void Pointer To Int / Double / String Pointer
Mar 7, 2013I have a function:
const void insertStuff(const void *key, const int value){
// I want to convert the void pointer into one
// of three types of pointers(int, string, or double)
switch(value){
case 0:
int *intPtr = key;
[Code] .....
But this causes an error of: "crosses initialization of int*intPtr"
What's the correct way of implementing this?
C :: Access Element Of Array Through A Pointer To A Pointer
Dec 25, 2013i have been fiddling with pointers but I don't understand how the proper syntax is written when I want to acces an element of an array through a pointer to a pointer...The code is all mostly just random bs for learning purposes. I marked the problem "// THIS LINE"
Code:
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#define MAX_DATA 100
int find_average(char *iden, ...) {
[Code]...
C :: How To Declare Two Dimensional Array Using A Pointer To A Pointer
Jul 16, 2013This is a sample program that declares a Matrix as a structure with an array as a pointer to a pointer. The following program is supposed to store a matrix in the structure "_Matrix" and later print the matrix just entered but it fails giving me a "segmentation fault". The sample code is given below
Code:
#include <stdio.h>
#include <stdlib.h>
struct _Matrix {
int row_size;
int col_size;
int **mat;
[Code] ......
C++ :: Pass Matrix By Reference Using Pointer Of Pointer
Jun 20, 2014i really don't know why has a error in my code, that pass a pointer of pointer (name of a matrix with 2 dimensions). Here is the source code of a simple example where appears segmentation fault when execute (but compiles normal):
#include <stdio.h>
#define LINHAS 3
#define COLUNAS 5
float a[LINHAS][COLUNAS];
void zeros(float **p,float m, float n){
int i,j;
for(i=0;i<m;i++)
[Code]...
C/C++ :: Copying A String From A Pointer To New Pointer
Mar 4, 2015I need to make a copy of a string that is defined by char *full and copy it into a different pointer defined by char *duplicate. I have written code to do this however it will not work and i cannot figure it out my code is as follows:
char *duplicate = (char *)malloc(strlen(full) + 1);
strcpy(duplicate, full); /*Make second version of full*/
char *Ptr = strtok(duplicate, " "); /*Split duplicate up*/
I have a full program written but i know this is where the problem is because i have used printf statements to see where the program fails. I get no errors and it compiles successfully but it hits this point of the program and it just stops and windows automatically shuts down the program.
char *full is pointing to:
"To be, or not to be? That is the question:
Whether 'tis nobler in the mind to suffer
The slings and arrows of outrageous fortune,
Or to take arms against a sea of troubles,"
I need to duplicate the string because i need to use strtok but i will need the original string later on so i need an unaltered version.
C++ :: Looping Through 2D Array Using Pointer To Pointer
Jan 3, 2013I have the following code :
Code:
#ifndef TDYNAMICARRAY_H
#define TDYNAMICARRAY_H
namespace Massive {
template<class T>
T **AllocateDynamic2DArray(int nRows,int nCols)
[Code] .....
I wish to know how to traverse or loop through a dynamic 2D array using pointer to pointer as returned by the code above. Like I would in a static T[20][20] 2D array.
C :: Calling Function Via Function Pointer Inside Structure Pointer
Mar 14, 2013I'm trying to call a function via a function pointer, and this function pointer is inside a structure. The structure is being referenced via a structure pointer.
Code:
position = hash->(*funcHash)(idNmbr);
The function will return an int, which is what position is a type of. When I compile this code,
I get the error: error: expected identifier before ( token.
Is my syntax wrong? I'm not sure what would be throwing this error.
C++ :: Cast Base Class Pointer To Derived Class Pointer
Feb 6, 2015I create an instance of a base class (not derived class) and assign it to base class pointer. Then, I convert it to a pointer to a derived class and call methods on it.
why does it work, if there is a virtual table?
when will it fail?
// TestCastWin.cpp : Defines the entry point for the console application.//
#include "stdafx.h"
#include <iostream>
class B
{
public:
B(double x, double y) : x_(x), y_(y) {}
double x() const { return x_; }
[Code] ....
C++ :: Accessing Inside Structure Via Struct Pointer To Struct Pointer
Jun 5, 2012"
#include <stdio.h>
struct datastructure {
char character;
};
void function(struct datastructure** ptr);
[Code] ....
These codes give these errors:
error: request for member 'character' in '* ptr', which is of non-class type 'datastructure*'
error: request for member 'character' in '* ptr', which is of non-class type 'datastructure*'
These errors are related to
"
*ptr->character='a';
printf("Ptr: %c",*ptr->character);
"
I want to access "character" data inside the structure "trial" by a pointer to pointer "ptr" inside function "function",but I couldn't find a way to do this.
C++ :: Pointer Point To Pointer?
Jan 30, 2014Is this the correct format to point a pointer (pointer1) to another pointer (pointer2)?
&pointer1 = &pointer2
I am kinda rusty when it comes to pointers ...
C++ :: Getting Segfault With Pointer To Pointer?
May 19, 2013I'm trying to store an array of vectors using a double pointer as a 2D array, but after the first "vector" (column) has been filled, I get a segfault. I correctly included all the libraries needed, and declared all the variables; I am using this function to allocate the space for the array:
double **vec_array(int rows,int clms)
/*allocates a double matrix with -rows- rows and -clms- columns */
{
int i;
double **m;
[Code].....
I get no error while compiling, but when I run the program I get a segfault right after having read the first vector: switching on the check I get in my output just the components of the first vector and then the segfault:
Terminal:
$ ./myprog input_data.dat
0.000000 0.512468 -0.152468
Segmentation fault (core dumped)
C :: Why A Char Pointer Increments 1 Where As Int Pointer Increments 4
Apr 25, 2014Code:
char *ptr;
printf("Output: %d %d %d
",sizeof(ptr), ptr, ptr+1);
Output: 4 214734480 214734481
int *ptr;
printf("Output: %d %d %d
",sizeof(ptr), ptr, ptr+1);
Output: 4 214734480 214734484 when size of the pointer is the same "4 bytes" whether its a char pointer or a int pointer, but why a char pointer increments 1 where as int pointer increments 4.
C :: How To Use Pointer To Struct
Mar 6, 2015how can I call and print the Pointer:
ptr->address
Code: #include<stdio.h>
struct account {
int address;
int value;
[code]....
C :: Integration Using Pointer
Apr 25, 2013So I was playing around with trying to do an integral using pointers. I've written what I'm trying to do already using arrays
Code:
#include <stdio.h>
#include <math.h>
#define RANGE 500 // Final temp = T0 + RANGE
int main() {
int i, j, h = 1, T0 = 300;
float k300 = 148, alpha = -1.25;
[Code] ...
Which works just fine. Instead I want to try to go through it using pointers. Is there a good way to go through the first loop above, something like?
Code:
#include <stdio.h>
#include <math.h>
#define N 501 // Final temp = T0 + N
int main() {
int T0 = 300;
float k300 = 148, alpha = -1.25;
[Code] ....