Using CAtlArray for a class member variable

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I would appreciate it if someone can provide me with a code sample for using CAtlArray as a member variable inside a class, where the array should hold a custom data structure.

I have defined the data structure:

C++

typedef struct
{
	int Status;
	CTime StatusDate;
} MyDataStructure;

Then, in my class, I define:

C++

private:
	CAtlArray<MyDataStructure> MyArray;

When I call RemoveAll(), or try to add a new item, I get an Access Violation error.
I tried to use SetCount() prior to adding members, but it didn't work as well.

Posted 6-Oct-12 12:21pm

Michael Haephrati

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Comments

cariolihome 6-Oct-12 19:18pm

Please, show Your code

7 solutions

Solution 6

How can I get notified, to the main even loop when this thread completes?

Posted 9-Oct-12 8:17am

Michael Haephrati

Solution 7

Use this ---
dwRet = WaitForSingleObject(HANDLE,TIME);

see the example ..
http://www.installsetupconfig.com/win32programming/threadprocesssynchronizationapis11_13.html[^]

when thread will be completed, use postmessage method to inform UI :D

Posted 9-Oct-12 19:03pm

Briti Sundar

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This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Briti Sundar · Accepted Answer · 2012-10-06T20:05:00

Solution 1

May be you have missed to malloc first before insert into MyArray.

C++

MyDataStructure* pNewStruct;
pNewStruct =(MyDataStructure* )malloc(sizeof(MyDataStructure));
MyArray.Add(pNewStruct);

Hope this will work.

Posted 6-Oct-12 20:05pm

Briti Sundar

Briti Sundar · Accepted Answer · 2012-10-08T20:56:00

This work for me and i get value after thread exit. Compare your code with me , you can understand your problem. Another thing CreateThread can not call a member function, so you must need a static function for this.,

C++

#include "stdafx.h"
#include <atlbase.h>
#include <atltime.h>
#include <atlcoll.h>
#include <atldebugapi.h>
 
class MyClass
{
public:
	typedef struct
	{
		CString* FullPath;
		CTime* StatusDate;
		MyClass* pClass;
	} _Item;

	MyClass();
	~MyClass();
	void StartThread();
	void* MyThread(void* arg);
	typedef _Item Item;
	Item MyItem;

	static void _MyThread(void* lpParam)
	{
		Item* obj = (Item* )lpParam;
		
		MyClass* a = obj->pClass;
		a->MyThread(lpParam);
	}
//private:
	CAtlArray<item*> MyArray;
};


MyClass::MyClass()
{
}
void MyClass::StartThread()
{
	HANDLE handle;
	int val=0;
	Item* MyNewItem = (Item* )malloc(sizeof(Item));
	//wcscpy(MyNewItem.FullPath.GetBuffer(),L"c:\\");
	MyNewItem->FullPath = new CString(L"c:\\");
	MyNewItem->pClass = this;
	handle = CreateThread( NULL, 0, (LPTHREAD_START_ROUTINE)&_MyThread, MyNewItem, 0, NULL);  
	if ( handle == NULL)  ExitProcess(0);
 
}
void* MyClass::MyThread(void* arg)
{
	Item* newObj = (Item* )arg; 
	MyArray.Add(newObj);
	return 0;
}
int WINAPI _tWinMain(HINSTANCE hInstance, HINSTANCE /*hPrevInstance*/, LPTSTR lpstrCmdLine, int nCmdShow)
{
	MyClass *myClass = new MyClass();
	myClass->StartThread();
	Sleep(200);  
	CString str;
	str.Format(L"\n\n--- PATH=%s --- \n\n",*(myClass->MyArray.GetAt(0)->FullPath));
	OutputDebugString(str);

	return 1;
}
</atldebugapi.h></atlcoll.h></atltime.h></atlbase.h>

Best of luck :D

Michael Haephrati · Accepted Answer · 2012-10-08T00:52:00

Something like

C++

// testproject.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <atlbase.h>
#include <atltime.h>
#include <atlcoll.h>
typedef struct
{
	CString FullPath;
	CTime StatusDate;
} Item;

class MyClass
{
public:
	MyClass();
	~MyClass();
	void StartThread();
	void* MyThread(void* arg);
	Item MyItem;
private:
	CAtlArray<item> *MyArray;
};

void MyClass::StartThread(void)
{
	HANDLE handle;
	int val=0;
	Item MyNewItem;
	wcscpy(MyNewItem.FullPath.GetBuffer(),L"c:\\");
	
	handle = CreateThread( NULL, 0, (LPTHREAD_START_ROUTINE) &MyClass::MyThread, &MyNewItem, 0, NULL);  
    if ( handle == NULL)  ExitProcess(0);

}
void* MyClass::MyThread(void* arg)
{
	Item* newObj = (Item* )arg; 
	MyArray->Add(*Item);
	
	return TRUE;
}
int _tmain(int argc, _TCHAR* argv[])
{
	MyClass *myClass = new MyClass;
	myClass->StartThread();
	return 1;
}




</item></atlcoll.h></atltime.h></atlbase.h>

Michael Haephrati · Accepted Answer · 2012-10-06T22:16:00

Solution 2

[ bappycse05] is correct but I also used a Thread which is a member function of a class and wanted it to access the class's member variables, but the moment the thread ends, any changes it makes in any member variables are erased.

Posted 6-Oct-12 22:16pm

Michael Haephrati

Updated 6-Oct-12 22:17pm

v2

Briti Sundar · Accepted Answer · 2012-10-07T18:30:00

It will be better if you post a little bit of code. However,
suppose classname is MyClass and your thread name MyThread. You call this thread from your class.
then try this..

C++

_beginthread(MyThread,0,this);

void* MyThread(void* arg)
{
   MyClass* newObj = (MyClass* )arg; 
  // now you can use all variable or method of this class using this object;
  newObj->MyArray.add(YourStructure); 
}

if this will not work for you then please post some code.

Well, try this code:

C++

// testproject.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <atlbase.h>
#include <atltime.h>
#include <atlcoll.h>
typedef struct
{
	CString FullPath;
	CTime StatusDate;
} Item;
 
class MyClass
{
public:
	MyClass();
	~MyClass();
	void StartThread();
	void* MyThread(void* arg);
	Item MyItem;
private:
	CAtlArray<item> *MyArray;
};
 
void MyClass::StartThread(void)
{
	HANDLE handle;
	int val=0;
	Item MyNewItem;
	wcscpy(MyNewItem.FullPath.GetBuffer(),L"c:\\");
	
	handle = CreateThread( NULL, 0, (LPTHREAD_START_ROUTINE) &MyClass::MyThread, &MyNewItem, 0, NULL);  
    if ( handle == NULL)  ExitProcess(0);
 
}
void* MyClass::MyThread(void* arg)
{
	Item* newObj = (Item* )arg; 
	MyArray->Add(*Item);
	
	return TRUE;
}
int _tmain(int argc, _TCHAR* argv[])
{
	MyClass *myClass = new MyClass;
	myClass->StartThread();
	return 1;
}

Using CAtlArray for a class member variable

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Using CAtlArray for a class member variable

7 solutions

Solution 1

Solution 5

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Solution 4

Solution 2

Solution 3

Solution 7

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