//}}AFX_VIRTUAL
// Implementation
protected:
HICON m_hIcon;
// Generated message map functions
//{{AFX_MSG(CMyDialog)
virtual BOOL OnInitDialog();
afx_msg void OnSysCommand(UINT nID, LPARAM lParam);
afx_msg void OnPaint();
afx_msg HCURSOR OnQueryDragIcon();
//}}AFX_MSG
afx_msg UINT OnNcHitTest(CPoint pt);
DECLARE_MESSAGE_MAP()
};
//{{AFX_INSERT_LOCATION}}
// Microsoft Visual C will insert additional declarations immediately before the previous line.
#endif // !defined(AFX_DRAGMOVEDLGDLG_H__4E4722C8_DE78_4AEC_97BC_73CEB2B525B3__INCLUDED_)
//////////////////////////////////////////////////////////////////////// DragMoveDlgDlg.cpp : implementation file
#include "stdafx.h"
#include "DragMoveDlg.h"
#include "DragMoveDlgDlg.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
CMyDialog::CMyDialog(CWnd* pParent /*=NULL*/)
: CDialog(CMyDialog::IDD, pParent)
{
//{{AFX_DATA_INIT(CMyDialog)
// NOTE: the ClassWizard will add member initialization here
//}}AFX_DATA_INIT
// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}
void CMyDialog::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
//{{AFX_DATA_MAP(CMyDialog)
// NOTE: the ClassWizard will add DDX and DDV calls here
//}}AFX_DATA_MAP
}
BEGIN_MESSAGE_MAP(CMyDialog, CDialog)
//{{AFX_MSG_MAP(CMyDialog)
ON_WM_SYSCOMMAND()
ON_BN_CLICKED(ID_APP_ABOUT,OnAbout)
ON_WM_PAINT()
ON_WM_QUERYDRAGICON()
//}}AFX_MSG_MAP
ON_WM_NCHITTEST()
END_MESSAGE_MAP()
/////////////////////////////////////////////////////////////////////////////
// CMyDialog message handlers
BOOL CMyDialog::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
return TRUE; // return TRUE unless you set the focus to a control
}
void CMyDialog::OnSysCommand(UINT nID, LPARAM lParam)
{
if ((nID & 0xFFF0) == IDM_ABOUTBOX)
{}
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 CMyDialog::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 CMyDialog::OnQueryDragIcon()
{
return (HCURSOR) m_hIcon;
}
void CMyDialog::OnAbout()
{
CAboutDlg().DoModal();
}
//////////////////
// Non-client hit-test handler to move window by its client area.
// If the user clicks anywhere on the client area, pretend it's the
// caption. Windows does the rest!
UINT CMyDialog::OnNcHitTest(CPoint pt)
{
CRect rc;
GetClientRect(&rc);
ClientToScreen(&rc);
return rc.PtInRect(pt) ? HTCAPTION : CDialog::OnNcHitTest(pt);
}
四、小结
本实例主要探讨了如何处理WM_HITTEST消息来"欺骗"Windows当前鼠标就在程序的标题栏中，从而实现对话框窗体的拖动。这种方法不仅适用于对话框程序，对于视图文档结构的应用程序也是适用的。
