How to Clear in Visual C++ 6.0

Hello.

I am doing a project on Visual C++ 6.0 and I have most of it completed. What I would like to do is have a button named "Clear". I have to buttons... one is "Clear" and the other is "Cancel". I would like to be able to press the button named "Clear" and it will clear all of my data so I can input new numbers. Can someone please help me with this part?

Here is my code...

Code:

// Proj2Dlg.cpp : implementation file
//

#include "stdafx.h"
#include "Proj2.h"
#include "Proj2Dlg.h"
#include "math.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
	CAboutDlg();

// Dialog Data
	//{{AFX_DATA(CAboutDlg)
	enum { IDD = IDD_ABOUTBOX };
	//}}AFX_DATA

	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CAboutDlg)
	protected:
	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
	//}}AFX_VIRTUAL

// Implementation
protected:
	//{{AFX_MSG(CAboutDlg)
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
	//{{AFX_DATA_INIT(CAboutDlg)
	//}}AFX_DATA_INIT
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CAboutDlg)
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
	//{{AFX_MSG_MAP(CAboutDlg)
		// No message handlers
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CProj2Dlg dialog

CProj2Dlg::CProj2Dlg(CWnd* pParent /*=NULL*/)
	: CDialog(CProj2Dlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CProj2Dlg)
	m_u1 = 0.0;
	m_u2 = 0.0;
	m_tc = 0.0;
	m_time = 0.0;
	m_res = 0.0;
	m_step = 0.0;
	m_display = _T("");
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CProj2Dlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CProj2Dlg)
	DDX_Text(pDX, IDC_EDT_U1, m_u1);
	DDX_Text(pDX, IDC_EDT_U2, m_u2);
	DDX_Text(pDX, IDC_EDT_TC, m_tc);
	DDX_Text(pDX, IDC_EDT_TIME, m_time);
	DDX_Text(pDX, IDC_EDT_RES, m_res);
	DDX_Text(pDX, IDC_EDT_STEP, m_step);
	DDX_Text(pDX, IDC_DISPLAY, m_display);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CProj2Dlg, CDialog)
	//{{AFX_MSG_MAP(CProj2Dlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_BTN_CANCEL, OnBtnCancel)
	ON_BN_CLICKED(IDC_DISPLAY, OnDisplay)
	ON_BN_CLICKED(IDC_CALCNGRAPH, OnCalcngraph)
	ON_BN_CLICKED(IDC_CALC, OnCalc)
	ON_BN_CLICKED(IDC_BTN_CLR, OnBtnClr)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CProj2Dlg message handlers

BOOL CProj2Dlg::OnInitDialog()
{
	CDialog::OnInitDialog();

	// Add "About..." menu item to system menu.

	// IDM_ABOUTBOX must be in the system command range.
	ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
	ASSERT(IDM_ABOUTBOX < 0xF000);

	CMenu* pSysMenu = GetSystemMenu(FALSE);
	if (pSysMenu != NULL)
	{
		CString strAboutMenu;
		strAboutMenu.LoadString(IDS_ABOUTBOX);
		if (!strAboutMenu.IsEmpty())
		{
			pSysMenu->AppendMenu(MF_SEPARATOR);
			pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
		}
	}

	// Set the icon for this dialog.  The framework does this automatically
	//  when the application's main window is not a dialog
	SetIcon(m_hIcon, TRUE);			// Set big icon
	SetIcon(m_hIcon, FALSE);		// Set small icon
	
	// TODO: Add extra initialization here
	m_u1 = 0.0;
	m_u2 = 0.0;
	m_tc = 0.0;
	m_time = 0.0;
	m_res = 0.0;
	m_step = 0.0;
	UpdateData(FALSE);

	return TRUE;  // return TRUE  unless you set the focus to a control
}

void CProj2Dlg::OnSysCommand(UINT nID, LPARAM lParam)
{
	if ((nID & 0xFFF0) == IDM_ABOUTBOX)
	{
		CAboutDlg dlgAbout;
		dlgAbout.DoModal();
	}
	else
	{
		CDialog::OnSysCommand(nID, lParam);
	}
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CProj2Dlg::OnPaint() 
{
	if (IsIconic())
	{
		CPaintDC dc(this); // device context for painting

		SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

		// Center icon in client rectangle
		int cxIcon = GetSystemMetrics(SM_CXICON);
		int cyIcon = GetSystemMetrics(SM_CYICON);
		CRect rect;
		GetClientRect(&rect);
		int x = (rect.Width() - cxIcon + 1) / 2;
		int y = (rect.Height() - cyIcon + 1) / 2;

		// Draw the icon
		dc.DrawIcon(x, y, m_hIcon);
	}
	else
	{
		CDialog::OnPaint();
	}
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CProj2Dlg::OnQueryDragIcon()
{
	return (HCURSOR) m_hIcon;
}

void CProj2Dlg::OnBtnCancel() 
{
	// TODO: Add your control notification handler code here
	OnCancel();
}

void CProj2Dlg::OnCalcngraph() 
{
	// TODO: Add your control notification handler code here
	UpdateData(TRUE);
	m_display = "You have selected to view both the calucations and the graph!";
	UpdateData(FALSE);
	
	CClientDC dc(this); // this is a class name
	
	CPen pen(PS_SOLID, 2, RGB(255, 0, 0));  // call another function - pen thickness
	CPen* ppen = dc.SelectObject(&pen);

	int x0 = 50;
	int y0 = 250;
	int length = 300;
	int height = 100;
	
	
	dc.Rectangle(x0, y0, x0 + length, y0 + height);
	

	
	double n = 5 * m_tc / m_step; // step is each incriminant of time
	double t;
	
	int x1;
	int y1;


	
	dc.MoveTo(x0, y0 + height);


	for (int i = 0; i <= n; i++)
	{
		t = i * m_step;
		m_res=m_u1 + (m_u2 - m_u1) * (1-exp(-t / (m_tc))); // change m_time to t because I am receiving a step from keyboard

		x1 = x0 + t / (5 * m_tc) * length; // add  the time to x0
		y1 = (y0 + height)- m_res / (m_u2 - m_u1) * height;

	// m_res=m_u1 + (m_u2 - m_u1) * (1-exp(-m_time / (m_tc))); // calculation for 1 t
		
		dc.LineTo(x1, y1);
		
		Sleep((int) (m_step * 1000));
	}


	UpdateData(FALSE);
}


void CProj2Dlg::OnCalc()  
{
	// TODO: Add your control notification handler code here
	UpdateData(TRUE);
	m_display = "You have selected to view only the calucations!";
	UpdateData(FALSE);

	double n = 5 * m_tc / m_step; // step is each incriminant of time
	double t;
	
	for (int i = 0; i <= n; i++)
	{
		t = i * m_step;
		
		m_res=m_u1 + (m_u2 - m_u1) * (1-exp(-t / (m_tc))); // change m_time to t because I am receiving a step from keyboard

	}


	UpdateData(FALSE);

}

void CProj2Dlg::OnBtnClr()
{
	// TODO: Add your control notification handler code here

}

void CProj2Dlg::OnDisplay()
{
	// TODO: Add your control notification handler code here
}

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How to Clear in Visual C++