System.NullReferenceException error in VC++.NET

[wakthar]

Hi,

I have a problem which I dont know whether its to do with proper construction of an object or with releasing memory in a destructor.

What I want to be able to do is have for example an array of strings so I can do the following

pszChannel[0] = "Hello";
pszChannel[1] = "World";
pszChannel[2] = "!!!!!";

so I can do for example

strcpy(m_pObject->pszChannel[0], "HELLO");

in another class.


I have created an object which has the following properties

#define MAX_NUM_CHANS = 3
#define MAX_STRING_LEN = 32

char* pszChannel[MAX_NUM_CHANS+1]; // IS IT OK
char* pszPart[MAX_NUM_CHANS+1]; // TO DO THIS
char* pszRange[MAX_NUM_CHANS+1]; // CONSTRUCTION
char szName[MAX_STRING_LEN+1]; // ???????
SAFEARRAY *psaDataArray;

What I want is to have the ability for the object to contain the following data
for example in the default contructor

CTH::CTH()
{
for (int i=0; ipszChannel[i] = new char[96];
strcpy(this->pszChannel[i], "");
this->pszPart[i] = new char[96];
strcpy(this-> pszPart [i], "");
this->pszRange[i] = new char[96];
strcpy(this-> pszRange [i], "");
}
this->szName = “Rotate”;
}



I can create the object fine and populate the data properties OK but when I want to delete the object
how do I delete the properties in the destructor ? What I ultimately require is to delete the object and free up all memory associated with this object.

If I try the following in the destructor I get an error

CTH::~CTH()
{
for (int i=0; ipszChannel[i];
delete [] this->pszPart[i];
delete [] this->pszRange[i];
}
this->szName = “”;

::SafeArrayDestroy(psaDataArray);
}



========== Exception Text ==========
System.NullReferenceException: Value null was found where an instance of an object was required.
at THLib.THIT.FileClose()
at THTest.Form1.Button1_Click(Object sender, EventArgs e) in C:\1\source\THTest\Form1.vb:line 92
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ButtonBase.WndProc(Message& m)
at System.Windows.Forms.Button.WndProc(Message& m)
at System.Windows.Forms.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)