enummetafile.cpp

WINDOWS2000开发人员指南源代码第五章的

// enummetafile.cpp : Defines the entry point for the application.
//

#include "stdafx.h"
#include "resource.h"

#define MAX_LOADSTRING 100

// Global Variables:
HINSTANCE hInst;                        // current instance
TCHAR szTitle[MAX_LOADSTRING];          // The title bar text
TCHAR szWindowClass[MAX_LOADSTRING];    // The title bar text

HENHMETAFILE g_hMetaFile = NULL;

// Foward declarations of functions included in this code module:
ATOM                MyRegisterClass(HINSTANCE hInstance);
BOOL                InitInstance(HINSTANCE, int);
void                ExitInstance();
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK    About(HWND, UINT, WPARAM, LPARAM);

HENHMETAFILE CreateEnhMetaFile(HWND hWnd);
void OnPaint(HWND hWnd);
int CALLBACK PlayMetaFileRecordProc(HDC hDC, HANDLETABLE* phTable,
    const ENHMETARECORD* pRecord, int numObjects, LPARAM lpClientData);


//
// WinMain: Entry point for the application
//
int APIENTRY WinMain
(
    HINSTANCE hInstance
   ,HINSTANCE /*hPrevInstance*/
   ,LPSTR     /*lpCmdLine*/
   ,int       nCmdShow
)
{
    MSG msg;
    HACCEL hAccelTable;

    // Initialize global strings
    LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
    LoadString(hInstance, IDC_ENUMMETAFILE, szWindowClass, MAX_LOADSTRING);
    MyRegisterClass(hInstance);

    // Perform application initialization:
    if (!InitInstance (hInstance, nCmdShow)) 
    {
        return FALSE;
    }

    hAccelTable = LoadAccelerators(hInstance, (LPCTSTR)IDC_ENUMMETAFILE);

    // Main message loop:
    while (GetMessage(&msg, NULL, 0, 0)) 
    {
        if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg)) 
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    ExitInstance();

    return msg.wParam;
}

//
// MyRegisterClass: registers the window class
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
    WNDCLASSEX wcex;

    wcex.cbSize = sizeof(WNDCLASSEX); 

    wcex.style          = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc    = (WNDPROC)WndProc;
    wcex.cbClsExtra     = 0;
    wcex.cbWndExtra     = 0;
    wcex.hInstance      = hInstance;
    wcex.hIcon          = LoadIcon(hInstance, (LPCTSTR)IDI_ENUMMETAFILE);
    wcex.hCursor        = LoadCursor(NULL, IDC_ARROW);
    wcex.hbrBackground  = (HBRUSH)(COLOR_WINDOW+1);
    wcex.lpszMenuName   = (LPCSTR)IDC_ENUMMETAFILE;
    wcex.lpszClassName  = szWindowClass;
    wcex.hIconSm        = LoadIcon(wcex.hInstance, (LPCTSTR)IDI_SMALL);

    return RegisterClassEx(&wcex);
}

//
// InitInstance: creates the window
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
    BOOL bReturn(FALSE);

    // Store instance handle in our global variable
    hInst = hInstance; 

    HWND hWnd = CreateWindow(szWindowClass, szTitle, 
        WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, 0, CW_USEDEFAULT,
        0, NULL, NULL, hInstance, NULL);
    if (hWnd)
    {
        g_hMetaFile = CreateEnhMetaFile(hWnd);

        ShowWindow(hWnd, nCmdShow);
        UpdateWindow(hWnd);
        bReturn = TRUE;     
    }

    return bReturn;
}

//
// ExitInstance: cleans up the resources created
//
void ExitInstance()
{
    if (g_hMetaFile != NULL)
    {
        DeleteEnhMetaFile(g_hMetaFile);
    }  
}

//
//  WndProc: main window window procedure
//
LRESULT CALLBACK WndProc
(
    HWND hWnd
   ,UINT message
   ,WPARAM wParam
   ,LPARAM lParam
)
{
    int wmId, wmEvent;

    switch (message) 
    {
        case WM_COMMAND:
            wmId    = LOWORD(wParam); 
            wmEvent = HIWORD(wParam); 
            // Parse the menu selections:
            switch (wmId)
            {
                case IDM_ABOUT:
                   DialogBox(hInst, (LPCTSTR)IDD_ABOUTBOX,
                       hWnd, (DLGPROC)About);
                   break;
                case IDM_EXIT:
                   DestroyWindow(hWnd);
                   break;
                default:
                   return DefWindowProc(
                       hWnd, message, wParam, lParam);
            }
        break;

        case WM_PAINT:
            OnPaint(hWnd);
        break;
        
        case WM_DESTROY:
            PostQuitMessage(0);
        break;
        
        default:
            return DefWindowProc(hWnd, message, wParam, lParam);
   }
   return 0;
}

//
//  CreateEnhMetaFile: creates a metafile
//
HENHMETAFILE CreateEnhMetaFile(HWND hWnd)
{
    HENHMETAFILE hMetaFile(NULL);

    // get a dc for the window
    HDC hDC = GetDC(hWnd);
   
    // set the mapping mode to himetric since metafiles
    // are created in .01 mm units
    int mapmodeOld = SetMapMode(hDC, MM_HIMETRIC); 

    // get the client rect and convert to logical units
    RECT rectClientDC;
    GetClientRect(hWnd, &rectClientDC); 
    DPtoLP(hDC, (LPPOINT)&rectClientDC, 2);
    
    // normalize rect, the bottom coordinate will be negative
    // in the himetric mapping mode
    rectClientDC.bottom *= -1;

    // restore the mapping mode
    SetMapMode(hDC, mapmodeOld);

    // create the enhanced metafile
    HDC hDCMeta = CreateEnhMetaFile(hDC, NULL, &rectClientDC, NULL);
    if (hDCMeta != NULL)
    {
        // get the metafile client window
        RECT rectClientMeta;
        GetClientRect(hWnd, &rectClientMeta); 
        DPtoLP(hDCMeta, (LPPOINT)&rectClientMeta, 2); 

        // draw a red line around the border
        HPEN hPenRedDot = CreatePen(PS_DOT, 1, RGB(255,0,0));
        HPEN hPenOld = (HPEN)SelectObject(hDCMeta, hPenRedDot);

        InflateRect(&rectClientMeta, -10, -10);
        Rectangle(hDCMeta, rectClientMeta.left, rectClientMeta.top,
            rectClientMeta.right, rectClientMeta.bottom);
    
        // draw an ellipse just inside the border with a dark
        // gray border and filled with a light gray brush
        InflateRect(&rectClientMeta, -10, -10);

        HPEN hPenGrey = CreatePen(PS_SOLID, 3, RGB(128,128,128));
        HBRUSH hBrush = (HBRUSH)GetStockObject(DC_BRUSH);
        SetDCBrushColor(hDCMeta, RGB(172,172,172));
        
        // select objects
        SelectObject(hDCMeta, hPenGrey);
        HBRUSH hBrushOld = (HBRUSH)SelectObject(hDCMeta, hBrush);

        // draw the ellipse
        Ellipse(hDCMeta, rectClientMeta.left, rectClientMeta.top,
            rectClientMeta.right, rectClientMeta.bottom);

        // select original objects
        SelectObject(hDCMeta, hBrushOld);
        SelectObject(hDCMeta, hPenOld);

        // close the metafile
        hMetaFile = CloseEnhMetaFile(hDCMeta);
    }

    ReleaseDC(hWnd, hDC);

    return hMetaFile;
}

//
// OnPaint:  handles the painting for the window
//
void OnPaint(HWND hWnd)
{
    PAINTSTRUCT ps;
    HDC hDC = BeginPaint(hWnd, &ps);
    
    if (g_hMetaFile != NULL)
    {
        RECT rectClient;
        GetClientRect(hWnd, &rectClient);
        EnumEnhMetaFile(hDC, g_hMetaFile,
            &PlayMetaFileRecordProc, NULL, &rectClient);
    }

    EndPaint(hWnd, &ps);
}

//
// PlayMetaFileRecordProc:  play the metafile record
//
int CALLBACK PlayMetaFileRecordProc
(
    HDC hDC
   ,HANDLETABLE* phTable
   ,const ENHMETARECORD* pRecord
   ,int numObjects
   ,LPARAM /*lpClientData*/
)
{
    switch (pRecord->iType)
    {
        case EMR_ELLIPSE:
        case EMR_RECTANGLE:
        case EMR_CREATEPEN:
        case EMR_CREATEBRUSHINDIRECT:
        default:
            PlayEnhMetaFileRecord(
                hDC, phTable, pRecord, numObjects);  
        break;
    }
    
    return 1;
}

//
// Mesage handler for about box.
//
LRESULT CALLBACK About
(
    HWND hDlg
   ,UINT message
   ,WPARAM wParam
   ,LPARAM /*lParam*/
)
{
    switch (message)
    {
        case WM_INITDIALOG:
            return TRUE;

        case WM_COMMAND:
            if (LOWORD(wParam) == IDOK || 
                LOWORD(wParam) == IDCANCEL) 
            {
                EndDialog(hDlg, LOWORD(wParam));
                return TRUE;
            }
        break;
    }

    return FALSE;
}