Windows Programming Help

[Amaranthine]

I'm fairly new to windows programming and am currently teaching myself MFC so I don't know the windows API at all.

My main area that you write in is based off of the CView class and I have a notepad type program right now. How do you get individual pieces out of the view? I found the
GetWindowText(LPTSTR lpszStringBuf, int nMaxCount) and the GetWindowTextLength() functions
but I only want one letter at a time. So how would I get one letter at a time out of the view and increment that point each time?

[Valmont]

Store the text in a CString or a char* for example and parse through the string to lookup the character you are interesting in.

Otherwise, to stay within your code using GetWindowTextLength:

char* buffer =  NULL;
length = GetWindowTextLength(whatever_control_box); //Like Edit box.
 //Add one for the terminating character.
length++;
// Size the buffer to hold all the data;
buffer = new char[length]; 
//Fill the bufer with text
GetWindowText(whatever_control_box, buffer, length); 
// Now iterate through "buffer" your C++ way.

[Amaranthine]

thankyou very much, I face a new problem.

void CWinEncrypterDoc::OnOptionEncrypt() 
{
        CWinEncrypterView* aView = CWinEncrypterView::GetView();// get current view
	char* buffer = NULL;    // create holder for text
	int length = aView->GetWindowTextLength();    // get text length
	length++;	// add room for terminating character
	buffer = new char[length];	// set buffer equal to size of text in view
	CString encrypted;    // initialize encryption holding CString
	aView->GetWindowText(buffer,length);    // get the text and store in buffer
	// loop through and xor accordingly
	for(int i = 0; i < length; i++)
		encrypted += buffer[i] |= static_cast<char>(m_Seed);
	// output encrypted text
	CEncryptedDlg aDlg;
	aDlg.m_Encrypted = encrypted;    // set text to show to encrypted text
	aDlg.DoModal();    // show dialog with xored text
}

I wrote this program in assembly a while back, but it got the text out of a file and was a 16 bit program.
This one works kind-of, but when you try to "decrypt"(un-xor) the text by simply xoring it again with the same value it just spits out the same value, why?
Is there an error in my logic?

(GetView() is a function I made that returns a pointer to the current view)

[Valmont]

|= is not an XOR operator but an OR-Assignment operator.
^ is the XOR operator for bitwise manipulation.

Furthermore, I am not sure if your proggy still would work. You need to convert the individual characters to asci integer and then use the XOR for manipulation back and forth. That will work guaranteed. Obviously you have to convert the integers (wich are the ASCI numbers) back to asci characters and store it in a string variable.

Also make sure to convert m_seed to an integer first, if not already.
And when you don't need buffer anymore, make sure you free the memory with delete[]!
Observe the subscript ( [] ) operator! When you use new [...], delete with delete[ ] .

[Amaranthine]

Thanks, I had always thought that |= was the xor assignment, when I switched it over to ^= it worked correctly.

If you care to see, here are my two added/edited lines:

encrypted += buffer[i] ^= static_cast<char>(m_Seed);
delete[] buffer;

(thanks for reminding me to free up the space with delete[])
Now I can go through and search for possible optimizations.