MFC CEdit: Could please somebody explain this ?

Hi all!

while learing to code a CEdit box i encouterd something that i don't understand.

The below code 1st pre-clears a string using ZeroMemory function.
The TRACE statement always gives CEDITN: 0 in the debug
window.

When commenting out ZeroMemory then CEDITN returns
suddenly the ammout of characters typed in.

Code:

/////////////////////////////////////////////////////////////////////////////
// CDlgNewString

void CDlgNewString::OnChangeEditNewString() 
{
	ZeroMemory(&m_cNewString[0], 14);

	CEdit *pEdit = (CEdit *)GetDlgItem(IDC_EDIT_NEWSTRING);

	int n = pEdit->GetLine (0, &m_cNewString[0]);
	TRACE("CEDITN: %ld\n", n);

	if (!n)
		GetDlgItem(IDOK)->EnableWindow(false);

	else
		GetDlgItem(IDOK)->EnableWindow(true);
}

Can somebody please tell, why ZeroMemory influences a CEdit Control ??

Regards,
Robert

Read the reference for CEdit::GetLine()
Notice the lpszBuffer parameter.

gg