Create Icons at Runtime and Show Them in the System Tray

// DynIconDlg.cpp : implementation file
//

#include "stdafx.h"
#include "DynIcon.h"
#include "DynIconDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#endif


// CAboutDlg dialog used for App About

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

// Dialog Data
	enum { IDD = IDD_ABOUTBOX };

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

// Implementation
protected:
	DECLARE_MESSAGE_MAP()
};

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

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

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
END_MESSAGE_MAP()


// CDynIconDlg dialog




CDynIconDlg::CDynIconDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CDynIconDlg::IDD, pParent)
	,m_nValue1(-10)
	,m_nValue2(-15)
	,m_bActiv(FALSE)
	,m_bFirstDefaultIcon(TRUE)
	,m_bFirstIcon1(TRUE)
	,m_bFirstIcon2(TRUE)
{
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

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

BEGIN_MESSAGE_MAP(CDynIconDlg, CDialog)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_WM_TIMER()
	//}}AFX_MSG_MAP
	ON_BN_CLICKED(IDOK,      &CDynIconDlg::OnBnClickedOk)
	ON_BN_CLICKED(IDC_START, &CDynIconDlg::OnBnClickedStart)
	ON_BN_CLICKED(IDC_STOP,  &CDynIconDlg::OnBnClickedStop)
	ON_MESSAGE(WM_TRAY, OnTray)//own message
	ON_WM_SYSCOMMAND()
END_MESSAGE_MAP()


// CDynIconDlg message handlers

BOOL CDynIconDlg::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
	


	//set the defaulticon in the tray
	SetDefaultIconInTray();

	CString strValue;

	strValue.Format(_T("%3d"),m_nValue1);
	SetDlgItemTextW(IDC_VALUE1, strValue);
	
	strValue.Format(_T("%3d"),m_nValue2);
	SetDlgItemTextW(IDC_VALUE2, strValue);
 
	((CButton*)GetDlgItem(IDC_START))->EnableWindow(TRUE);
	((CButton*)GetDlgItem(IDC_STOP))->EnableWindow(FALSE);
	((CButton*)GetDlgItem(IDOK))->EnableWindow(TRUE);





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

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

			
			case SC_MINIMIZE:
				//if the dialog should be minimized, the dialog will be hidden
				//without a button in the taskbar
				ShowWindow(SW_HIDE);
				return;
				break;

			
			case SC_CLOSE:
				//before the dialog will be closed, we have to clear the icon(s)
				if(m_bActiv){
					//if the measurement is activ, there are two icons to delete
					ClearIcon1();
					ClearIcon2();
				}
				else{
					//if the measurement is not activ, there is only one icon to delete
					ClearDefaultIconInTray();
				}
				break;
			
			
			default:
				break;

		}


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

		SendMessage(WM_ICONERASEBKGND, reinterpret_cast<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 function to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CDynIconDlg::OnQueryDragIcon()
{
	return static_cast<HCURSOR>(m_hIcon);
}

void CDynIconDlg::SetDefaultIconInTray()
{
	//create a handle for the default icon	
	HICON hIcon;
	
	HINSTANCE hInst = AfxFindResourceHandle(MAKEINTRESOURCE(IDI_ICON1),RT_GROUP_ICON);
				
	hIcon = (HICON)LoadImage(hInst,MAKEINTRESOURCE(IDI_ICON1),IMAGE_ICON,16,16,LR_DEFAULTCOLOR);
    	
	//NOTIFYCONDATA structure	
	NOTIFYICONDATA tnid;
 
	//set the values
    tnid.cbSize = sizeof(NOTIFYICONDATA); 
    tnid.hWnd = m_hWnd; 
    tnid.uID = IDI_ICON1;//resourcename of the icon 
    tnid.uFlags = NIF_MESSAGE | NIF_ICON | NIF_TIP; 
    tnid.uCallbackMessage = WM_TRAY;//user created message 
    tnid.hIcon = hIcon; 

	//defaultstring for the tooltip
	m_strTooltip.Format(_T("Temperature-Monitor (inactiv)"));

	//copy the string to the NOTIFYCONDATA structure
	lstrcpyn(tnid.szTip, m_strTooltip, sizeof(tnid.szTip)); 
	

	//call the Shell_NotifyIcon
	//because it is the first time, we have to use NIM_ADD
	Shell_NotifyIcon(NIM_ADD, &tnid); 
 
    //now the icon is shown in the tray and we can free the icon 
	DestroyIcon(hIcon); 
}


void CDynIconDlg::ClearDefaultIconInTray()
{
	NOTIFYICONDATA tnid;
	
	tnid.hWnd = m_hWnd; 
	tnid.uID = IDI_ICON1;//the default icon

	//Shell_NotifyIcon with NIM_DEL
	Shell_NotifyIcon(NIM_DELETE, &tnid); 	
}


void CDynIconDlg::ChangeValues()
{
	//this method is used to simulate the dynamic of the meassured values
	//increment the values and display them in the dialog


	CString strValue;

	m_nValue1++;
	if(m_nValue1 > 10) m_nValue1 = -10;

	strValue.Format(_T("%3d"),m_nValue1);
	SetDlgItemTextW(IDC_VALUE1, strValue);

	m_nValue2++;
	if(m_nValue2 > 10) m_nValue2 = -15;

	strValue.Format(_T("%3d"),m_nValue2);
	SetDlgItemTextW(IDC_VALUE2, strValue);
}


void CDynIconDlg::CreateIcons()
{
	CreateIcon1();
	CreateIcon2();

}
void CDynIconDlg::CreateIcon1()
{ 
	using namespace Gdiplus;
	
	//we need a widechar array for the value
	wchar_t strValue[4];
	int size = sizeof(strValue)/sizeof(wchar_t);// because the wchar_t requires two byte!!!

	swprintf( strValue, size, L"%3d", m_nValue1 );//the prefix L means, that the string should be a widechar

	//if you already have a char array including the value
	//then you don't need the swprintf(), but
	//you have to convert the char array to a widechar array
	/*
	char txt[4];
	sprintf_s(txt, sizeof(txt),"%3d", m_nValue1);
	MultiByteToWideChar(CP_ACP, 0, txt, -1, strValue, size);
	*/	
	
	//you can change the colors depending on the value
	//here it should be white only

	//white pen to draw some lines in the icon
	Pen whitePen(Color(255, 255, 255));
	
	//white brush for the text
	SolidBrush whiteBrush(Color(255,255,255));
	
	//create a small font to write the values in the bitmap
	Font font(L"Tahoma",8);//, FontStyleRegular,UnitPixel);
	
	//origin for the string
	PointF origin(-1, 1);
	
	//alignment for the string
	StringFormat format;
	format.SetAlignment(StringAlignmentNear);
	

	
	//create a new bitmap with 16x16 pixel
	Bitmap bitmap(16,16);
	
	//use the bitmap to draw
	Graphics *graph = Graphics::FromImage(&bitmap);
	
	//draw two horizontale lines
	//just for the show
	graph->DrawLine(&whitePen, 0, 15, 15, 15);
	graph->DrawLine(&whitePen, 0,  0, 15,  0);

	//draw the string including the value
	//here we need the widechar-array
	graph->DrawString(strValue, -1, &font, origin, &format, &whiteBrush);
	
	//create the icon and put it to the handle (member of our class)
	bitmap.GetHICON(&m_hIcon1);

}

void CDynIconDlg::CreateIcon2()
{ 
	using namespace Gdiplus;


	//we need a widechar array for the value
	wchar_t strValue[4];
	int size = sizeof(strValue)/sizeof(wchar_t);// because the wchar_t requires two byte!!!

	swprintf( strValue, size, L"%3d", m_nValue2 );//the prefix L means, that the string should be a widechar

	//if you already have a char array including the value
	//then you don't need the swprintf(), but
	//you have to convert the char array to a widechar array
	/*
	char txt[4];
	sprintf_s(txt, sizeof(txt),"%3d", m_nValue2);
	MultiByteToWideChar(CP_ACP, 0, txt, -1, strValue, size);
	*/
	
	
	//you can change the colors depending on the value
	//here it should be white only

	//white pen to draw some lines in the icon
	Pen whitePen(Color(255, 255, 255));
	
	//white brush for the text
	SolidBrush whiteBrush(Color(255,255,255));
	
	//create a small font to write the values in the bitmap
	Font font(L"Tahoma",8);//, FontStyleRegular,UnitPixel);
	
	//origin for the string
	PointF origin(-1, 1);
	
	//alignment for the string
	StringFormat format;
	format.SetAlignment(StringAlignmentNear);
	

	
	//create a new bitmap with 16x16 pixel
	Bitmap bitmap(16,16);
	
	//use the bitmap to draw
	Graphics *graph = Graphics::FromImage(&bitmap);
	
	//draw two horizontale lines
	//just for the show
	graph->DrawLine(&whitePen, 0, 15, 15, 15);
	graph->DrawLine(&whitePen, 0,  0, 15,  0);

	//draw the string including the value
	//here we need the widechar-array
	graph->DrawString(strValue, -1, &font, origin, &format, &whiteBrush);
	
	//create the icon and put it to the handle (member of our class)
	bitmap.GetHICON(&m_hIcon2);

}


void CDynIconDlg::PushIcons()
{
	//at the first time we have to clear the defaulticon
	if(m_bFirstDefaultIcon){
		m_bFirstDefaultIcon = FALSE;
		ClearDefaultIconInTray();
	}


	//we change the content of the tooltip
	//we use the same tooltip for the two icons
	m_strTooltip.Format(_T("Value1:%3d\nValue2:%3d"),m_nValue1, m_nValue2);

	//update the icons
	PushIcon2();
	PushIcon1();
}

void CDynIconDlg::PushIcon1()
{
	// set NOTIFYCONDATA structure	
	NOTIFYICONDATA tnid;
 
    tnid.cbSize = sizeof(NOTIFYICONDATA); 
    tnid.hWnd = m_hWnd; 
    tnid.uID = ICON_VALUE1; //Resourcename
    tnid.uFlags = NIF_MESSAGE | NIF_ICON | NIF_TIP; 
    tnid.uCallbackMessage = WM_TRAY;//user message 
    tnid.hIcon = m_hIcon1; //handle of the created icon

	//copy the string to the NOTIFYCONDATA structure
	lstrcpyn(tnid.szTip, m_strTooltip, sizeof(tnid.szTip));
	
	
	if(m_bFirstIcon1){
		
		//for the first time we have to use the Shell_NotifyIcon with NIM_ADD
		//to add the icon to the tray
		Shell_NotifyIcon(NIM_ADD, &tnid); 
		m_bFirstIcon1 = FALSE;
	}
	else{
		//the icon already exists
		//Shell_NotifyIcon with NIM_MODIFY
		Shell_NotifyIcon(NIM_MODIFY, &tnid);
	}
 
	// free icon 
	DestroyIcon(m_hIcon1); 
}

void CDynIconDlg::PushIcon2()
{
	// set NOTIFYCONDATA structure	
	NOTIFYICONDATA tnid;
 
    tnid.cbSize = sizeof(NOTIFYICONDATA); 
    tnid.hWnd = m_hWnd; 
    tnid.uID = ICON_VALUE2; //resourcename
    tnid.uFlags = NIF_MESSAGE | NIF_ICON | NIF_TIP; 
    tnid.uCallbackMessage = WM_TRAY;//user message 
    tnid.hIcon = m_hIcon2; //handle of the created icon

	//copy the string to the NOTIFYCONDATA structure
	lstrcpyn(tnid.szTip, m_strTooltip, sizeof(tnid.szTip));
	
	
	if(m_bFirstIcon2){
		
		//for the first time we have to use the Shell_NotifyIcon with NIM_ADD
		//to add the icon to the tray
		Shell_NotifyIcon(NIM_ADD, &tnid); 
		m_bFirstIcon2 = FALSE;
	}
	else{
		//the icon already exists
		//Shell_NotifyIcon with NIM_MODIFY
		Shell_NotifyIcon(NIM_MODIFY, &tnid);
	}
 
	// free icon 
	DestroyIcon(m_hIcon2); 
}

void CDynIconDlg::ClearIcon1()
{
	NOTIFYICONDATA tnid;
	
	tnid.hWnd = m_hWnd; 
	tnid.uID = ICON_VALUE1;

	//Shell_NotifyIcon with NIM_DEL
	Shell_NotifyIcon(NIM_DELETE, &tnid); 	
}

void CDynIconDlg::ClearIcon2()
{
	NOTIFYICONDATA tnid;
	
	tnid.hWnd = m_hWnd; 
	tnid.uID = ICON_VALUE2;

	//Shell_NotifyIcon with NIM_DEL
	Shell_NotifyIcon(NIM_DELETE, &tnid); 	
}






void CDynIconDlg::OnTimer(UINT_PTR nIDEvent)
{	
	switch(nIDEvent){
		case TIMER1: 
				ChangeValues();
				CreateIcons();
				PushIcons();
				break;
		
		default: break;
	}

}


void CDynIconDlg::OnBnClickedStart()
{
	//start Timer1
	SetTimer(TIMER1, 1000, NULL);

	//set the states of the buttons
	((CButton*)GetDlgItem(IDC_START))->EnableWindow(FALSE);
	((CButton*)GetDlgItem(IDC_STOP))->EnableWindow(TRUE);
	((CButton*)GetDlgItem(IDOK))->EnableWindow(FALSE);

	m_bActiv = TRUE;

}

void CDynIconDlg::OnBnClickedStop()
{
	//stop Timer1
	KillTimer(TIMER1);

	//clear icon1
	ClearIcon1();

	//clear icon2
	ClearIcon2();

	//set the defaulticon in the tray
	SetDefaultIconInTray();

	//set the states of the buttons
	((CButton*)GetDlgItem(IDC_START))->EnableWindow(TRUE);
	((CButton*)GetDlgItem(IDC_STOP))->EnableWindow(FALSE);
	((CButton*)GetDlgItem(IDOK))->EnableWindow(TRUE);

	m_bActiv = FALSE;

	m_bFirstDefaultIcon = TRUE;
	m_bFirstIcon1 = TRUE;
	m_bFirstIcon2 = TRUE;
}

void CDynIconDlg::OnBnClickedOk()
{
	//clear the Icon in the tray
	ClearDefaultIconInTray();
	OnOK();
}


LRESULT	CDynIconDlg::OnTray(WPARAM wParam, LPARAM lParam)
{
	//Messagehandler of the icons in the tray

	UINT uMouseMsg = (UINT) lParam;
	
	switch(uMouseMsg){
	
		case WM_LBUTTONDBLCLK:
			
			//show or hide the dialog

			if(IsWindowVisible())
				ShowWindow(SW_HIDE);
			else
				ShowWindow(SW_NORMAL);
				BringWindowToTop();
			break;
		

		case WM_RBUTTONDOWN:
			//here you can popup a menue
			//PopupMenue();
			break;

		default: 
			break;
	}

	return 0;
}