C / C++ / MFC

//
// A gloabal rectangle.
CRect rTextMain;


//
// In my timer;
InvalidateRect(&rTextMain); // Your steps said to do this after, I tried both.

rTextMain.top = val1; rTextMain.left.......

UpdateWindow();



//
// In OnPaint;
CFont newFont;
newFont.CreateFont(15, 0, 0, 0, 400, 0, 0, 0, 0, 0, 0, 0, 0, _T("MS Sans Serif"));
CFont *oldFont = dc.SelectObject(&newFont);

CString sWords = "test";
dc.DrawText(sWords, &rTextMain, DT_TOP | DT_LEFT)

Mark Salsbery
Microsoft MVP - Visual C++

Mr Simple wrote:

Create CDC from DC

Mr Simple wrote:

CDC select object (global/main region)

Mark Salsbery
Microsoft MVP - Visual C++

<br />
CPaintDC dc(this); // device context for painting<br />
CDC *floatCDC = new CDC;<br />
floatCDC->CreateCompatibleDC(&dc);

#pragma once

#include <atlimage.h>

// CMovingTextDialog dialog

class CMovingTextDialog : public CDialog
{
    DECLARE_DYNAMIC(CMovingTextDialog)

public:
    CMovingTextDialog(CWnd* pParent = NULL);   // standard constructor
    virtual ~CMovingTextDialog();

// Dialog Data
    enum { IDD = IDD_DIALOG2 };  <font color="Red">//<-- Use the correct dialog resource ID here!</font>

protected:
    virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support

    DECLARE_MESSAGE_MAP()
public:
    virtual BOOL OnInitDialog();
protected:
    virtual void OnOK();
public:
    CImage BkImage;
    UINT_PTR MoveTimer;
    CString TextStr;
    CSize TextSize;
    CRect TextRect;

    afx_msg void OnPaint();
    afx_msg BOOL OnEraseBkgnd(CDC* pDC);
    afx_msg void OnTimer(UINT_PTR nIDEvent);

};



// MovingTextDialog.cpp : implementation file
//

#include "stdafx.h"
#include "MFCTester.h"
#include "MovingTextDialog.h"


// CMovingTextDialog dialog

IMPLEMENT_DYNAMIC(CMovingTextDialog, CDialog)

CMovingTextDialog::CMovingTextDialog(CWnd* pParent /*=NULL*/)
    : CDialog(CMovingTextDialog::IDD, pParent)
{
    BkImage.Load(_T("e:\\test.bmp"));  <font color="Red">//<-- load your own bmp/jpg/tiff here!</font>
    MoveTimer = 0;
    TextStr = _T("Moving Text");
    TextSize.cx = TextSize.cy = 0;
    TextRect.SetRect(0,0,0,0);
}

CMovingTextDialog::~CMovingTextDialog()
{
}

void CMovingTextDialog::DoDataExchange(CDataExchange* pDX)
{
    CDialog::DoDataExchange(pDX);
}


BEGIN_MESSAGE_MAP(CMovingTextDialog, CDialog)
    ON_WM_PAINT()
    ON_WM_ERASEBKGND()
    ON_WM_TIMER()
END_MESSAGE_MAP()


// CMovingTextDialog message handlers

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

    MoveTimer = ::SetTimer(*this, (UINT_PTR)12345, 10, NULL);

    return TRUE;  // return TRUE unless you set the focus to a control
    // EXCEPTION: OCX Property Pages should return FALSE
}

void CMovingTextDialog::OnOK()
{
    ::KillTimer(*this, MoveTimer);
    MoveTimer = 0;

    CDialog::OnOK();
}

void CMovingTextDialog::OnPaint()
{
    CPaintDC dc(this); 

    if (0 == TextSize.cx)
    {
        // Initialize TextSize and TextRect
        TextSize = dc.GetTextExtent(TextStr);
        TextRect.SetRect(0, 0, TextSize.cx, TextSize.cy);
        TextRect.InflateRect(4, 4);
    }

    dc.SetBkMode(TRANSPARENT);

    dc.DrawText(TextStr, &TextRect, DT_LEFT | DT_TOP);

}

BOOL CMovingTextDialog::OnEraseBkgnd(CDC* pDC)
{
    CRect ClientRect;
    GetClientRect(&ClientRect);

    BkImage.StretchBlt(*pDC, 0, 0, ClientRect.Width(), ClientRect.Height());

    return TRUE;//CDialog::OnEraseBkgnd(pDC);
}

void CMovingTextDialog::OnTimer(UINT_PTR nIDEvent)
{
    if (0 != TextSize.cx)
    {
        InvalidateRect(&TextRect);

        CRect ClientRect;
        GetClientRect(&ClientRect);

        TextRect.OffsetRect(2, 2);

        if (TextRect.right > ClientRect.right || TextRect.bottom > ClientRect.bottom)
        {
            TextRect.SetRect(0, 0, TextSize.cx, TextSize.cy);
            TextRect.InflateRect(4, 4);
        }

        UpdateWindow();
    }

    CDialog::OnTimer(nIDEvent);
}

<br />
class CNotWorking :<br />
	public CWnd<br />
{<br />
public:<br />
	CNotWorking(void);<br />
	~CNotWorking(void);<br />
	void CreateTransparent(CWnd *pParent);<br />
<br />
	DECLARE_MESSAGE_MAP()<br />
	afx_msg void OnPaint();<br />
	afx_msg void OnTimer(UINT nIDEvent);<br />
<br />
private:<br />
	CRect rTextRect;<br />
	UINT tTicker;<br />
<br />
};

<br />
BEGIN_MESSAGE_MAP(CNotWorking, CWnd)<br />
ON_WM_PAINT()<br />
ON_WM_TIMER()<br />
END_MESSAGE_MAP()<br />
<br />
<br />
CNotWorking::CNotWorking(void)<br />
{<br />
	rTextRect.SetRect(0, 0, 40, 20);<br />
	tTicker = 0;<br />
<br />
}<br />
<br />
CNotWorking::~CNotWorking(void)<br />
{<br />
}<br />
<br />
void CNotWorking::CreateTransparent(CWnd *pParent)<br />
{<br />
		// Create & flag as existing.<br />
		CWnd::CreateEx(NULL, NULL, _T("Transparent"), WS_CHILD, 20, 20, 500, 500, pParent->GetSafeHwnd(), NULL);<br />
<br />
		tTicker = ::SetTimer(*this, (UINT_PTR)12345, 20, NULL);<br />
<br />
		ShowWindow(SW_SHOW);<br />
}<br />
<br />
void CNotWorking::OnPaint()<br />
{<br />
	CPaintDC dc(this); // device context for painting<br />
<br />
<br />
	dc.SetBkMode(TRANSPARENT);<br />
	CString textStr = "test";<br />
	dc.DrawText(textStr, &rTextRect, DT_LEFT | DT_TOP);<br />
<br />
<br />
}<br />
<br />
void CNotWorking::OnTimer(UINT nIDEvent)<br />
{<br />
	InvalidateRect(rTextRect);<br />
	rTextRect.OffsetRect(0, 2);<br />
	UpdateWindow();<br />
<br />
	CWnd::OnTimer(nIDEvent);<br />
}

Mark Salsbery wrote:

Your code works for me.

Mark Salsbery wrote:

you don't need to preserve a DC between WM_PAINT messages.

led mike wrote:

don't you mean you should not?

Mark Salsbery
Microsoft MVP - Visual C++

Mark Salsbery wrote:

what multi-column combobox?

(Foo( &counter ), counter);

George_George wrote:

I do not understand how this statement works,

(Foo( &counter ), counter);

George_George wrote:

I have tested that the simple statement (without comment) also works.

George_George wrote:

What is the benefit and function to add , and counter in macro definition?

void Foo (int* input)
{
	*input = 100;

	return;
}

#define GETFOO  (Foo( &counter ), counter)
void main()
{
int i = GETFOO;
}