I need to create an object of a mfc derived CFormView class that's not in the doc/template (a second view class). But it was generated with a protected ctor. Here's the code explanation with comments.
I'm thinking all the normal classes of the Doc/View template are created starting with this code, but within the template code base.
Code:
CSingleDocTemplate* pDocTemplate; pDocTemplate = new CSingleDocTemplate(IDR_MAINFRAME, RUNTIME_CLASS(CViewSwitchDoc), //<-expands to-> ((CRuntimeClass*)(&CViewSwitchDoc::classCViewSwitchDoc)), RUNTIME_CLASS(CMainFrame), // main SDI frame window RUNTIME_CLASS(CViewSwitchView));
But I have generated "another view" using the "Add Class" Wizard, it's a derived class of mfc CFormView which I named ViewForm. However I'm having a problem creating an instance of it because of the generated protected ctor and pulls a compile error of not being able to access ctor. Below are the header and implementation files of this said ViewForm class. How to create an object of this view ? Did I go about it all the wrong way since it's not in the doc/template group ?
// ViewForm.h file #pragma once // ViewForm form view class ViewForm : public CFormView { DECLARE_DYNCREATE(ViewForm)
I 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)
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"
public class ColorGenetics { public static hk1Class jw; public static linkedClass link; }
[code]...
Code builds fine but compiler says I tried to use bject link w/o providing an instance. Class linkedClass has an instance of Class hk1Class set to var jw1.I had linkedClass useing the same var jw for the object instance. I changed it to jw1 thinking that would clear it up and it didn't.
I need to send same instance of object of a class in two function (Main function and thread function). The class is something like this:
//The class need to have constructor. Class ABC { public: DWORD *IdG; ABC(int number) { IdG = new DWORD[number]; } }obj(32);
The obj(32) is called in following two function. Function F1 is called using thread in main function.
void F1() { obj.test; } int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd) { obj.test1; _beginthread(F1,0,(void*)number); }
The code works well when the object of class ABC is created as shown above. My problem is the value that is passed in the object ('32') is to be read from the file.
If I read the file and create object separately in Main function and function 'F1' then , function 'F1' is not executed.
How to create same instance of object for Main function and function 'F1' with value passed in the object taken from the file.
Are the objects in both vectors the same instance of the object? Like if I called vectorOne[0].setValue(somethingDifferent); would the value be changed for the object in both vectorOne and vectorTwo? If not, how do I make sure that I only have one instance of the object I'm trying to store in multiple vectors?
I'm trying to make a "Rain" application, by drawing some lines on the form, and then they must fall. So here is my start code:
public partial class Form1 : Form { public Form1() { InitializeComponent(); } Random r = new Random(); Graphics paper; Line line;
[Code] ....
So when I start debugging I get the "Object reference not set to an instance of an object." error. If I remove the comments lines at "timer1_Tick" this error doesn't appear of course. What can I do to escape from this because it follows me everywhere I go />. I tried to make with arrays, but same problem.
class Excuse {... public string Description { get; set; } public string Results { get; set; } public DateTime LastUsed { get; set; } public string ExcusePath { get; set; } ....}
[Code] ...
When I run it, I do get the messagebox popping up with the correct description, but then nothing happens. When I debug, I see the fields under the UpdateForm() method are set to null.
I'm guessing this happening because it is looking at the 'currentExcuse' that was declared in the form body. I thought however that redeclaring 'currentExcuse' in the method would overwrite this instance or am I wrong?
I am facing a real-life problem, it can be simplified as below:
#include <iostream> using namespace std; class B; class A { public: void f1(A a) {} void f2(B b) {}
[Code]...
There is no problem at all with the f1(), it compiles and executes without any problem. But f2() gives compilation error. How to solve this?
The error message is: error: 'b' has incomplete type This is just to define the function f2() in a class, that uses an instance of its child class as one of its arguments.
I am putting a instance o the Vehicle Class inside the constructor of the Calculate Class then calling it later. I get a warning saying the variable is not used and a error when I try to used the functions from the vehicle class saying use of undeclared identifier.
Okay so I have a class Student, which takes a number and a vector as a parameter for the constructor. Everything works well, until I output the values of the vector for every instance. The problem is that the same vector is being shared with EVERY instance I create, but I want it to be unique for every single one!
I was wondering if (in C++) you can instantiate a class (class foo) then have said class return the already instantiated object. (foo::instance())
In other words, can I have a class return it's-self via it's own methods? I want to be able to create a class (i.e. class foo) early in my program so it is already setup and ready to go. Then, farther down the line, I want to be able to call functions from that class without having to pass that object as an argument to my calling function. Can I do something like so:
MyClass::ReturnSelf()->foo(); or MyClass::ReturnSelf().foo();
I know that it is possible to pass a class instance to a function, but in my experience, if said function changes any variables of the class, they don't actually get changed. For example, we have class object, that has a member int number = 5. Lets say we have two functions, func1() and func2, which are not members of class object. If we pass object to func1() which, lets say, increases number by 5 (so now number = 10), at the end of that function number still = 5.
Is there a way to bypass this and have functions alter class variables permanently?
I know that I can pass variables by reference, but, in my experience, such a thing does not work with vectors (which I am also dealing with), so simple passing the desired variables by reference won't work.
I'm trying to learn as much C++ as I can. I was writing a program that mixes linked lists and classes. There is the class "Obj" which only holds an integer called 'data' and the classic "struct node" structure for linked list, but this time the "node" structure will hold an instance of "Obj" Class and the next* pointer.
#include <iostream> using namespace std; class Obj { private: int data; public:
class card { public: int id; int val; }; card card1; card1.id = 1; card1.val = 2; card card2; card2.id = 2; card2.val = 45;
etc...
So my question is firstly, is there a better way to implement this? (a vector of classes or something maybe?) and how can I call up a specific instance of the class. For example, if I want the val of a specific instance of the class, how best can I do that?
I'm trying to change the values of some instance variables in my Controller Class so that when the user inserts values into main class it changes for Controller.
class Controller { public: Controller(); ~Controller(); double PCFreq; __int64 CounterStart;
[Code] ....
The user should be able to choose which foo the want to use. So I create an object of controller in main like this
Controller* con = new Controller()
Now my issues is, when I take user input (an integer) and try to do this
con->choice1 = choice1;
only the object of con's choice1 is = to user input.
However back at the class for Controller, choice1 hasn't received a value.
I can't initialize through Controllers constructor because I get the user input through a switch statement and the range of con would only be as far as the case.
