openbmpdlg.cpp

visual c++ 实例编程

// ***********************************************************************************
//
// BmpDlg.cpp : implementation file
//
// ************************************************************************************

#include "stdafx.h"
#include "OpenBmpDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

// In order to ease use, these values have been hard coded in bmpdlg.rc
// This avoids the need for another header file.

#define IDC_PREVIEW         (5000)
#define IDC_PREVIEWBTN	    (5001)	
#define IDC_WIDTH           (5002)
#define IDC_HEIGHT          (5003)
#define IDC_DEPTH           (5004)
#define IDC_FSIZE           (5005)
#define IDC_SHOWPREVIEW     (5006)

HBITMAP COpenBmpDialog::hpreview = NULL;
BOOL COpenBmpDialog::m_showpreview = TRUE;

// Proprietary Hook function for open dialog

UINT APIENTRY OFNHookProc( HWND hdlg, UINT uiMsg, WPARAM wParam, LPARAM lParam )
{
    
LPDRAWITEMSTRUCT lpdis;
BITMAP bm;
LPNMHDR pnmh;
char filename[1024],str[255];
int height,height2,width,width2;
NMHDR nmh;
    
    switch (uiMsg)
    {
        case WM_COMMAND:
            
            if (LOWORD(wParam) == IDC_SHOWPREVIEW)
            {
                COpenBmpDialog::m_showpreview = IsDlgButtonChecked(hdlg,IDC_SHOWPREVIEW);

                if (!COpenBmpDialog::m_showpreview)
                {                    
                    if (COpenBmpDialog::hpreview)
                        DeleteObject(COpenBmpDialog::hpreview);

                    COpenBmpDialog::hpreview = NULL;

                    HWND wnd = GetDlgItem(hdlg,IDC_PREVIEWBTN);

                    InvalidateRect(wnd,NULL,TRUE);    

                    SetDlgItemText(hdlg,IDC_WIDTH,"");
                    SetDlgItemText(hdlg,IDC_HEIGHT,"");
                    SetDlgItemText(hdlg,IDC_DEPTH,"");
                    SetDlgItemText(hdlg,IDC_FSIZE,"");

                }
                else
                {
                    
                    nmh.code = CDN_SELCHANGE;

                    OFNHookProc(hdlg, WM_NOTIFY, 0, (LPARAM)&nmh);
                }
            }

            break;

        case WM_DRAWITEM:

            if (COpenBmpDialog::hpreview)
            {
                lpdis = (LPDRAWITEMSTRUCT)lParam;
                        
                GetObject(COpenBmpDialog::hpreview,sizeof(BITMAP),&bm);

                CPoint size(bm.bmWidth,bm.bmHeight);
                                                
                HDC dcmem = CreateCompatibleDC(lpdis->hDC);
      
                HBITMAP old = (HBITMAP)SelectObject(dcmem,COpenBmpDialog::hpreview);
				
				//调整显示位置
				//如果宽度大于高度，上下空出
                if (bm.bmWidth > bm.bmHeight)
                {

                    height = lpdis->rcItem.bottom - lpdis->rcItem.top;

                    float ratio = (float)bm.bmHeight/(float)bm.bmWidth;                 
                    
                    lpdis->rcItem.bottom  = (long) (lpdis->rcItem.top + (lpdis->rcItem.right-lpdis->rcItem.left)*ratio);

                    height2 = (height - (lpdis->rcItem.bottom - lpdis->rcItem.top))/2;

                    lpdis->rcItem.top += height2;
                    lpdis->rcItem.bottom += height2;

                }
				//如果高度大于宽度，左右空出
                else
                {

                    width = lpdis->rcItem.right - lpdis->rcItem.left;

                    float ratio = (float)bm.bmWidth/(float)bm.bmHeight;                 
                    
                    lpdis->rcItem.right  = (long) (lpdis->rcItem.left + (lpdis->rcItem.bottom-lpdis->rcItem.top)*ratio);

                    width2 = (width - (lpdis->rcItem.right - lpdis->rcItem.left))/2;

                    lpdis->rcItem.left += width2;
                    lpdis->rcItem.right += width2;

                }
                    
                StretchBlt(lpdis->hDC,lpdis->rcItem.left,lpdis->rcItem.top,lpdis->rcItem.right-lpdis->rcItem.left,lpdis->rcItem.bottom-lpdis->rcItem.top,dcmem,0,0,bm.bmWidth,bm.bmHeight,SRCCOPY);

                SelectObject(dcmem,old);

                DeleteDC(dcmem);
            }

            break;

        case WM_NOTIFY:
        
            pnmh = (LPNMHDR) lParam;

            if (pnmh->code == CDN_FILEOK)
            {
                if (COpenBmpDialog::hpreview)
                        DeleteObject(COpenBmpDialog::hpreview);

                // This avoids an assert

                _AFX_THREAD_STATE* pThreadState = AfxGetThreadState();
	            pThreadState->m_pAlternateWndInit = NULL;
                return 0;
            }


            if (pnmh->code ==  CDN_INITDONE)
            {
               if (COpenBmpDialog::hpreview)
                    DeleteObject(COpenBmpDialog::hpreview);

                CheckDlgButton(hdlg,IDC_SHOWPREVIEW,TRUE);
                return 0;
            }

            if (pnmh->code == CDN_SELCHANGE)
            {

                if (!IsDlgButtonChecked(hdlg,IDC_SHOWPREVIEW))
                    return 0;
                
                SendMessage(GetParent(hdlg),CDM_GETFILEPATH ,1024,(LPARAM)filename);                

                if (COpenBmpDialog::hpreview)
                    DeleteObject(COpenBmpDialog::hpreview);
               
                COpenBmpDialog::hpreview = (HBITMAP)LoadImage(AfxGetInstanceHandle(),filename,IMAGE_BITMAP,0,0,LR_LOADFROMFILE);//|LR_CREATEDIBSECTION);

                HWND wnd = GetDlgItem(hdlg,IDC_PREVIEWBTN);

                InvalidateRect(wnd,NULL,TRUE);

                if (COpenBmpDialog::hpreview)
                {
                    GetObject(COpenBmpDialog::hpreview,sizeof(BITMAP),&bm);
        
                    wsprintf(str,"宽度: %d 像素",bm.bmWidth);
                    SetDlgItemText(hdlg,IDC_WIDTH,str);

                    wsprintf(str,"高度: %d 像素",bm.bmHeight);
                    SetDlgItemText(hdlg,IDC_HEIGHT,str);
                    
                    switch (bm.bmBitsPixel)
                    {
                        case 1:
                            SetDlgItemText(hdlg,IDC_DEPTH,"颜色: 2 (黑白)");
                            break;
                        case 4:
                            SetDlgItemText(hdlg,IDC_DEPTH,"颜色: 16");
                            break;

                        case 8:
                            SetDlgItemText(hdlg,IDC_DEPTH,"颜色: 256");
                            break;

                        case 16:
                            SetDlgItemText(hdlg,IDC_DEPTH,"颜色: 16位");
                            break;


                        case 24:
                            SetDlgItemText(hdlg,IDC_DEPTH,"颜色: 24位");
                            break;

						case 32:
                            SetDlgItemText(hdlg,IDC_DEPTH,"颜色: 32位");
                            break;

                        default:
                            SetDlgItemText(hdlg,IDC_DEPTH,"");
                    }

                    OFSTRUCT o;

                    HFILE f = OpenFile(filename,&o,OF_READ);

                    wsprintf(str,"长度: %ld Kb",GetFileSize((HANDLE)f,NULL)/1024);

                    SetDlgItemText(hdlg,IDC_FSIZE,str);
                    
                    _lclose(f);
                }
                else
                {
                    SetDlgItemText(hdlg,IDC_WIDTH,"");
                    SetDlgItemText(hdlg,IDC_HEIGHT,"");
                    SetDlgItemText(hdlg,IDC_DEPTH,"");
                    SetDlgItemText(hdlg,IDC_FSIZE,"");
                }	               
            }	
    }
    return 0;
}



/////////////////////////////////////////////////////////////////////////////
// COpenBmpDialog

IMPLEMENT_DYNAMIC(COpenBmpDialog, CHMHOpenFile)



COpenBmpDialog::COpenBmpDialog(BOOL bOpenFileDialog, LPCTSTR lpszDefExt, LPCTSTR lpszFileName,
		DWORD dwFlags, LPCTSTR lpszFilter, CWnd* pParentWnd) :
		CHMHOpenFile(bOpenFileDialog, lpszDefExt, lpszFileName, dwFlags, lpszFilter, pParentWnd)
{

    m_ofn.lpstrFilter = "位图文件 (*.bmp)\0*.bmp\0"\
                        "所有文件 (*.*)\0*.*\0\0";                            

    m_ofn.Flags |= (OFN_HIDEREADONLY |OFN_ENABLEHOOK| OFN_EXPLORER  |OFN_ENABLETEMPLATE);
    m_ofn.lpstrTitle=_T("选择位图...");
    m_ofn.hInstance = AfxGetInstanceHandle();
    m_ofn.lpTemplateName = MAKEINTRESOURCE(IDC_PREVIEW);
    m_ofn.lpfnHook = OFNHookProc;          
}


BEGIN_MESSAGE_MAP(COpenBmpDialog, CHMHOpenFile)
	//{{AFX_MSG_MAP(COpenBmpDialog)
		// NOTE - the ClassWizard will add and remove mapping macros here.
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()