ModelessDialogDemo.cpp

#include "pch.h"
#include "framework.h"
#include "ModelessDialogDemo.h"
#include "ModelessDialogDemoDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#endif

BEGIN_MESSAGE_MAP(CModelessDialogDemoApp, CWinApp)
	ON_COMMAND(ID_HELP, &CWinApp::OnHelp)
END_MESSAGE_MAP()

CModelessDialogDemoApp::CModelessDialogDemoApp()
{
}

CModelessDialogDemoApp theApp;

BOOL CModelessDialogDemoApp::InitInstance()
{
	CWinApp::InitInstance();
	SetRegistryKey(_T("MyApp"));
	CModelessDialogDemoDlg * dlg = new CModelessDialogDemoDlg();
	m_pMainWnd = dlg;
	dlg->Create(IDD_MODELESSDIALOGDEMO_DIALOG);
	dlg->ShowWindow(SW_SHOW);
	MSG msg;
    BOOL ret;
    while ((ret = GetMessage(&msg, nullptr, 0, 0)) != 0) {
        if (ret == -1)
            continue;
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return (BOOL)msg.wParam;
}

ModelessDialogDemo.h

#pragma once

#include "resource.h"

class CModelessDialogDemoApp : public CWinApp
{
public:
	CModelessDialogDemoApp();
	virtual ~CModelessDialogDemoApp() {}
	virtual BOOL InitInstance();

	DECLARE_MESSAGE_MAP()
};

extern CModelessDialogDemoApp theApp;

ModelessDialogDemoDlg.cpp

#include "pch.h"
#include "framework.h"
#include "ModelessDialogDemo.h"
#include "ModelessDialogDemoDlg.h"
#include "afxdialogex.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#endif

CModelessDialogDemoDlg::CModelessDialogDemoDlg(CWnd* pParent)
	: CDialogEx(IDD_MODELESSDIALOGDEMO_DIALOG, pParent)
{
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CModelessDialogDemoDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialogEx::DoDataExchange(pDX);
}

BEGIN_MESSAGE_MAP(CModelessDialogDemoDlg, CDialogEx)
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_WM_CLOSE()
END_MESSAGE_MAP()

BOOL CModelessDialogDemoDlg::OnInitDialog()
{
	CDialogEx::OnInitDialog();
	SetIcon(m_hIcon, TRUE);
	SetIcon(m_hIcon, FALSE);
	return TRUE;
}

void CModelessDialogDemoDlg::OnPaint()
{
	if (IsIconic()) {
		CPaintDC dc(this);
		SendMessage(WM_ICONERASEBKGND, reinterpret_cast<WPARAM>(dc.GetSafeHdc()), 0);
		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;
		dc.DrawIcon(x, y, m_hIcon);
	}
	else {
		CDialogEx::OnPaint();
	}
}

HCURSOR CModelessDialogDemoDlg::OnQueryDragIcon()
{
	return static_cast<HCURSOR>(m_hIcon);
}

void CModelessDialogDemoDlg::OnClose()
{
	PostQuitMessage(0);
}

ModelessDialogDemoDlg.h

#pragma once

class CModelessDialogDemoDlg : public CDialogEx
{
public:
	CModelessDialogDemoDlg(CWnd* pParent = nullptr);
	virtual ~CModelessDialogDemoDlg() {}
	virtual void OnCancel() {}
	virtual void OnOK() {}
	afx_msg void OnClose();

#ifdef AFX_DESIGN_TIME
	enum { IDD = IDD_MODELESSDIALOGDEMO_DIALOG };
#endif

protected:
	virtual void DoDataExchange(CDataExchange* pDX);
	virtual BOOL OnInitDialog();
	afx_msg void OnPaint();
	afx_msg HCURSOR OnQueryDragIcon();

protected:
	HICON m_hIcon;

	DECLARE_MESSAGE_MAP()
};