THREAD | TO CREATE AND IMPLEMENT THE USE OF THEREAD IN VC++

OBJECTIVE:
To implement the use of threads in vc++.
PROCEDURE:
1. Run the MFC appwizard(dll) to generate the application c:\thread
2. Select the ingle document in step 1 of appwizard
3. Select all the default settings except printing and print preview
4. Using the resource view, right click on the dialog and select the new dialog
5. Create new dialog box named IDC_PROGRESS1
6. Name the new dialog on IDD_COMPUTE using properties
7. The default OK button can be changed to IDC_START
8. Leave the default cancel button as such
9. By clicking on the dialog IDD_COMPUTE the system will automatically ask for a class name ive the classname as CComputeDlg
10. Using the class wizard map the message BN_CLICKED to the IDC_START, IDC_CANCEL objects
11. Declare the following in the compute DLG.H file next to #ENDIF
#define WM_THREADFINISHED
class CComputeDlg : public CDialog
{
LRESULT OnThreadFinished(WPARAM wparam,LPARAM lparam);
private:
int m_nTimer;
public:
enum{nMaxCount=10000};
12. Using class wizard map the message WM_TIMER to the CComputeDlg.cpp files as follows
void CComputeDlg::OnTimer(UINT nIDEvent)
{
CProgressCtrl*pBar=(CProgressCtrl*)GetDlgItem(IDC_PROGRESS1);
pBar->SetPos(g_nCount*100/nMaxCount);
CDialog::OnTimer(nIDEvent);
}
13. Type the following in compute Dlg.cpp type the definition of the thread before the constructor next to #endif
int g_nCount=0;
UINT ComputeThreadProc(LPVOID pParam)
{
volatile int nTemp;
for(g_nCount=0;g_nCountEnableWindow(FALSE);
AfxBeginThread(ComputeThreadProc,GetSafeHwnd(),THREAD_PRIORITY_NORMAL);
}
void CComputeDlg::OnCancel()
{
if(g_nCount==0)
{
CDialog::OnCancel();
}
else
{
g_nCount=nMaxCount;
}
}
15. Type the OnThreadFinished definition in the end of ComputeDlg.cpp file
LRESULT CComputeDlg::OnThreadFinished(WPARAM wparam,LPARAM lparam)
{
CDialog::OnOK();
return 0;
}
16. Using the class wizard map the CThreadView class an edit the following
void CThreadView::OnLButtonDown(UINT nFlags, CPoint point)
{
dlg.DoModal();
CView::OnLButtonDown(nFlags, point);
}
17. And in OnDraw function of CThreadView.cpp type the following
pDC->TextOut(0,0,"press the left mouse button here");
18. Include the header file of ComputeDlg in CThreadView.cpp
#include "ComputeDlg.h"
19. Compile and run and test the application
PROGRAM:
SOURCE FILES:
Computedlg.cpp :

 

#include "stdafx.h"
#include "thread.h"
#include "ComputeDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
/////////////////////////////////////////////////////////////////////////////
// CComputeDlg dialog
int g_nCount=0;
UINT ComputeThreadProc(LPVOID pParam)
{
volatile int nTemp;
for(g_nCount=0;g_nCountEnableWindow(FALSE);
AfxBeginThread(ComputeThreadProc,GetSafeHwnd(),THREAD_PRIORITY_NORMAL);
}
void CComputeDlg::OnCancel()
{
// TODO: Add extra cleanup here
if(g_nCount==0)
{
CDialog::OnCancel();
}
else
{
g_nCount=nMaxCount;
}
}
void CComputeDlg::OnTimer(UINT nIDEvent)
{
// TODO: Add your message handler code here and/or call default
CProgressCtrl*pBar=(CProgressCtrl*)GetDlgItem(IDC_PROGRESS1);
pBar->SetPos(g_nCount*100/nMaxCount);
CDialog::OnTimer(nIDEvent);
}
LRESULT CComputeDlg::OnThreadFinished(WPARAM wparam,LPARAM lparam)
{
CDialog::OnOK();
return 0;
}
Threadview.cpp :
// threadView.cpp : implementation of the CThreadView class
#include "stdafx.h"
#include "thread.h"
#include "threadDoc.h"
#include "threadView.h"
#include "ComputeDlg.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
/////////////////////////////////////////////////////////////////////////////
// CThreadView
IMPLEMENT_DYNCREATE(CThreadView, CView)

BEGIN_MESSAGE_MAP(CThreadView, CView)
//{{AFX_MSG_MAP(CThreadView)
ON_WM_LBUTTONDOWN()
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CThreadView construction/destruction

CThreadView::CThreadView()
{

}
CThreadView::~CThreadView()
{
}
BOOL CThreadView::PreCreateWindow(CREATESTRUCT& cs)
{
// TODO: Modify the Window class or styles here by modifying
// the CREATESTRUCT cs

return CView::PreCreateWindow(cs);
}
/////////////////////////////////////////////////////////////////////////////
// CThreadView drawing

void CThreadView::OnDraw(CDC* pDC)
{
CThreadDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
// TODO: add draw code for native data here
pDC->TextOut(0,0,"press the left mouse button here");
}
/////////////////////////////////////////////////////////////////////////////
// CThreadView diagnostics
#ifdef _DEBUG
void CThreadView::AssertValid() const
{
CView::AssertValid();
}

void CThreadView::Dump(CDumpContext& dc) const
{
CView::Dump(dc);
}
CThreadDoc* CThreadView::GetDocument() // non-debug version is inline
{
ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CThreadDoc)));
return (CThreadDoc*)m_pDocument;
}
#endif //_DEBUG
/////////////////////////////////////////////////////////////////////////////
// CThreadView message handlers
void CThreadView::OnLButtonDown(UINT nFlags, CPoint point)
{
dlg.DoModal();
CView::OnLButtonDown(nFlags, point);
}
HEADER FILES:

Computedlg.h :
#if !defined(AFX_COMPUTEDLG_H__62A874DD_70BF_4129_BE3F_1BD11DCF341D__INCLUDED_)
#define AFX_COMPUTEDLG_H__62A874DD_70BF_4129_BE3F_1BD11DCF341D__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000
// ComputeDlg.h : header file
//
#define WM_THREADFINISHED WM_USER +5
UINT ComputeThreadProc(LPVOID pParam);
/////////////////////////////////////////////////////////////////////////////
// CComputeDlg dialog
class CComputeDlg : public CDialog
{
// Construction
LRESULT OnThreadFinished(WPARAM wparam,LPARAM lparam);
private:
int m_nTimer;
public:
enum{nMaxCount=10000};
CComputeDlg(CWnd* pParent = NULL); // standard constructor
// Dialog Data
//{{AFX_DATA(CComputeDlg)
enum { IDD = IDD_COMPUTE };
// NOTE: the ClassWizard will add data members here
//}}AFX_DATA
// Overrides
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CComputeDlg)
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support
//}}AFX_VIRTUAL
protected:

// Generated message map functions
//{{AFX_MSG(CComputeDlg)
afx_msg void OnStart();
virtual void OnCancel();
afx_msg void OnTimer(UINT nIDEvent);
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};
//{{AFX_INSERT_LOCATION}}
// Microsoft Visual C++ will insert additional declarations immediately before the previous line.
#endif // !defined(AFX_COMPUTEDLG_H__62A874DD_70BF_4129_BE3F_1BD11DCF341D__INCLUDED_)