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第15章 设备无关位图_15.2 显示和打印DIB

Posted on 2015-08-03 12:18  浅墨浓香  阅读(915)  评论(0编辑  收藏  举报
15.2.1 探究DIB

(1)DIB文件的结构

整个文件

紧凑DIB(整个文件除文件头)

文件头(File Header)

信息头(Information Header)

信息头(Information Header)

颜色表(Color Table)

颜色表(Color Table)

像素位(Pixel Bits)

像素位(Pixel Bits)

 

 注意:①紧凑DIB在内存中是连续的,即整个DIB存在单个内存块中

           ②DIB载入内存时,像素位与信息头可以分别存在两个内存块,即内存不连续。

(2)像素位指针的求法

15.2.2 从像素到像素

(1)SetDIBitsToDevice函数——显示没有拉伸和压缩的DIB

参数

含义

hdc

设备环境句柄

xDst

目标矩形左上角x坐标(逻辑单位),这里的“左上角”指视觉上图像的左上角。

yDst

目标矩形左上角y坐标(逻辑单位)

cxSrc

源矩形宽度

1、这四个参数可以决定是显示整个DIB或只显示一部分。

2、对于自上而下的DIB,因BITMAPINFOHEADER的biHeight为负数,所以cySrc应设置为biHeight的绝对值,即biHeight永远要设为正数。

3、无论映射模式怎样,在输出设备上显示的DIB总是cxSrc像素宽,cySrc像素高。

cySrc

源矩形高度

xSrc

源x坐标

ySrc

源y坐标

yScan

指定DIB中起始扫描线的编号(见后面的详细分析)。

用来每次按顺序显示DIB的一部分。

通常yScan=0,cyScan=DIB的高度。

cyScan

DIB扫描线数目

pBits

像素位指针

pInfo

DIB信息头指针

fClrUse

指向BITMAPINFO结构中的成员bmiColors是否包含明确的RGB值或对调色板进行索引的值。取值为下列之一,这些值的含义如下:

DIB_PAL_COLORS(1):表示颜色表由16位的索引值数组组成,利用这些值可对当前选中的逻辑调色板进行索引。

DIB_RGB_COLORS(0):表示颜色表包含原义的RGB值。

返回值:返回函数调用后,显示DIB的所用的扫描行个数。

【ShowDib1程序】
效果图

 

/*------------------------------------------------------------
SHOWDIB1.C -- Show a DIB in the client area
(c) Charles Petzold, 1998
------------------------------------------------------------*/

#include <windows.h>
#include "resource.h"
#include "DibFile.h"

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

static TCHAR szAppName[] = TEXT("ShowDib1");
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
                   PSTR szCmdLine, int iCmdShow)
{
    HWND         hwnd;
    MSG          msg;
    WNDCLASSEX   wndclass;
    HACCEL       hAccel;

    wndclass.style = CS_HREDRAW | CS_VREDRAW;
    wndclass.cbSize = sizeof(WNDCLASSEX);
    wndclass.lpfnWndProc = WndProc;
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.hInstance = hInstance;
    wndclass.hIcon = LoadIcon(hInstance, szAppName);
    wndclass.hIconSm = LoadIcon(hInstance, szAppName);
    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndclass.lpszMenuName = szAppName;
    wndclass.lpszClassName = szAppName;

    if (!RegisterClassEx(&wndclass))
    {
        MessageBox(NULL, TEXT("This program requires Windows NT!"),
                   szAppName, MB_ICONERROR);
        return 0;
    }

    hwnd = CreateWindow(szAppName,                  // window class name
                        TEXT("Show DIB #1"), // window caption
                        WS_OVERLAPPEDWINDOW,        // window style
                        CW_USEDEFAULT,              // initial x position
                        CW_USEDEFAULT,              // initial y position
                        CW_USEDEFAULT,              // initial x size
                        CW_USEDEFAULT,              // initial y size
                        NULL,                       // parent window handle
                        NULL,                       // window menu handle
                        hInstance,                  // program instance handle
                        NULL);                     // creation parameters

    ShowWindow(hwnd, iCmdShow);
    UpdateWindow(hwnd);
    hAccel = LoadAccelerators(hInstance, szAppName);
    while (GetMessage(&msg, NULL, 0, 0))
    {
        if (!TranslateAccelerator(hwnd, hAccel, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }
    return msg.wParam;
}


LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    static BITMAPFILEHEADER* pbmfh;
    static BITMAPINFO*       pbmi;
    static BYTE*             pBits;

    static TCHAR   szFileName[MAX_PATH], szTitleName[MAX_PATH];
    static int     cxClient, cyClient, cxDib, cyDib;
    HDC    hdc;
    PAINTSTRUCT ps;
    BOOL         bSuccess;

    switch (message)
    {
    case WM_CREATE:

        DibFileInitialize(hwnd);
        return 0;

    case WM_INITMENUPOPUP:
        EnableMenuItem((HMENU)wParam, IDM_FILE_SAVE, pbmfh ? MF_ENABLED : MF_GRAYED);
        return 0;

    case WM_SIZE:
        cxClient = LOWORD(lParam);
        cyClient = HIWORD(lParam);
        return 0;

    case WM_COMMAND:
        switch (LOWORD(wParam))
        {
        case IDM_FILE_OPEN:
            //显示打开对话框
            if (!DibFileOpenDlg(hwnd, szFileName, szTitleName))
                return 0;

            //如果DIB文件己被载入,释放内存
            if (pbmfh)
            {
                free(pbmfh);
                pbmfh = NULL;
            }

            //将整个DIB加载到内存中
            SetCursor(LoadCursor(NULL, IDC_WAIT));
            ShowCursor(TRUE);

            pbmfh = DibLoadImage(szFileName);

            ShowCursor(FALSE);
            SetCursor(LoadCursor(NULL, IDC_ARROW));

            //使客户区无效,以便后面的绘图并擦除以前客户区显示的内容
            InvalidateRect(hwnd, NULL, TRUE);

            if (pbmfh == NULL)
            {
                MessageBox(hwnd, TEXT("Cannot load DIB file"), szAppName, 0);
                return 0;
            }

            //获取指向DIB信息头的指针和指向像素位的指针
            pbmi = (BITMAPINFO*)(pbmfh + 1);
            pBits = (BYTE*)pbmfh + pbmfh->bfOffBits;

            //获取图像的宽度和高度
            if (pbmi->bmiHeader.biSize == sizeof(BITMAPCOREHEADER))
            {
                cxDib = ((BITMAPCOREHEADER*)pbmi)->bcWidth;
                cyDib = ((BITMAPCOREHEADER*)pbmi)->bcHeight;
            } else
            {
                cxDib = pbmi->bmiHeader.biWidth;
                cyDib = abs(pbmi->bmiHeader.biHeight);
            }
            return 0;

        case IDM_FILE_SAVE:

            //显示保存对话框
            if (!DibFileSaveDlg(hwnd, szFileName, szTitleName))
                return 0;

            //将DIB位图保存到文件中
            SetCursor(LoadCursor(NULL, IDC_WAIT));
            ShowCursor(TRUE);

            bSuccess = DibSaveImage(szFileName, pbmfh);

            ShowCursor(FALSE);
            SetCursor(LoadCursor(NULL, IDC_ARROW));

            if (!bSuccess)
                MessageBox(hwnd, TEXT("Cannot save DIB file"), szAppName, 0);

            return 0;
        }
        break;

    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);

        if (pbmfh)
        {
            SetDIBitsToDevice(hdc,
                              0,
                              0,
                              cxDib,   //像素宽度
                              cyDib,   //像素高度
                              0,       //xSrc
                              0,       //ySrc
                              0,       //第一扫描线
                              cyDib,   //扫描线数目
                              pBits,   //像素位
                              pbmi,
                              DIB_RGB_COLORS);
        }

        EndPaint(hwnd, &ps);
        return 0;

    case WM_DESTROY:
        if (pbmfh)
            free(pbmfh);

        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd, message, wParam, lParam);
}

//DibFile.h

/*-----------------------------------------------------
DIBFILE.H ----  Header File for DIBFILE.C
------------------------------------------------------*/
#pragma  once
#include <windows.h>

void DibFileInitialize(HWND hwnd);

BOOL DibFileOpenDlg(HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName);
BOOL DibFileSaveDlg(HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName);

BITMAPFILEHEADER*  DibLoadImage(PTSTR pstrFileName);

BOOL               DibSaveImage(PTSTR pstrFileName, BITMAPFILEHEADER*);

//DibFile.c

#include "DibFile.h"

static OPENFILENAME ofn;
void DibFileInitialize(HWND hwnd)
{
    static TCHAR szFilter[] = TEXT("Bitmap Files (*.BMP)\0*.bmp\0")\
        TEXT("All Files(*.*)\0*.*\0\0");

    ofn.lStructSize = sizeof(OPENFILENAME);
    ofn.hwndOwner = hwnd;
    ofn.hInstance = NULL;
    ofn.lpstrFilter = szFilter;
    ofn.lpstrCustomFilter = NULL;
    ofn.nMaxCustFilter = 0;
    ofn.nFilterIndex = 0;
    ofn.lpstrFile = NULL;  //在打开和关闭中设置
    ofn.nMaxFile = MAX_PATH;
    ofn.lpstrFileTitle = NULL; //在打开和关闭函数中设置
    ofn.nMaxFileTitle = MAX_PATH;
    ofn.lpstrInitialDir = NULL;
    ofn.lpstrTitle = NULL;
    ofn.Flags = 0;     //在打开和关闭函数中设置
    ofn.nFileOffset = 0;
    ofn.nFileExtension = 0;
    ofn.lpstrDefExt = TEXT("bmp"); //默认扩展名
    ofn.lCustData = 0;
    ofn.lpfnHook = NULL;
    ofn.lpTemplateName = NULL;
}

BOOL DibFileOpenDlg(HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName)
{
    ofn.hwndOwner = hwnd;
    ofn.lpstrFile = pstrFileName;
    ofn.lpstrFileTitle = pstrTitleName;
    ofn.Flags = 0;
    return GetOpenFileName(&ofn);
}

BOOL DibFileSaveDlg(HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName)
{
    ofn.hwndOwner = hwnd;
    ofn.lpstrFile = pstrFileName;
    ofn.lpstrFileTitle = pstrTitleName;
    ofn.Flags = OFN_OVERWRITEPROMPT;
    return GetSaveFileName(&ofn);
}

BITMAPFILEHEADER*  DibLoadImage(PTSTR pstrFileName)
{
    BOOL                bSuccess;
    DWORD               dwFileSize, dwHighSize, dwBytesRead;
    HANDLE              hFile;
    BITMAPFILEHEADER*   pbmfh;

    hFile = CreateFile(pstrFileName, GENERIC_READ, FILE_SHARE_READ, NULL,
                       OPEN_EXISTING, FILE_FLAG_SEQUENTIAL_SCAN, NULL);

    if (hFile == INVALID_HANDLE_VALUE)
        return NULL;

    //返回文件大小的低位字,保存在dwFileSize中,高位字保存在dwHighSize中
    dwFileSize = GetFileSize(hFile, &dwHighSize);

    if (dwHighSize)  //文件太大,超过4G则dwHighSize不为0,退出
    {
        CloseHandle(hFile);
        return NULL;
    }

    //为位图文件分配内存,内存指针由文件头指针保管
    pbmfh = malloc(dwFileSize);
    if (!pbmfh)
    {
        CloseHandle(hFile);
        return NULL;
    }

    //读位图文件到内存
    bSuccess = ReadFile(hFile, pbmfh, dwFileSize, &dwBytesRead, NULL);
    CloseHandle(hFile);

    if ((!bSuccess) || (dwBytesRead != dwFileSize) ||
        (pbmfh->bfType != *(WORD*)"BM") ||   //位图标志“BM”
        (pbmfh->bfSize != dwFileSize))
    {
        free(pbmfh);
        return NULL;
    }

    return pbmfh;
}

BOOL               DibSaveImage(PTSTR pstrFileName, BITMAPFILEHEADER* pbmfh)
{
    BOOL     bSuccess;
    DWORD    dwBytesWritten;
    HANDLE   hFile;

    hFile = CreateFile(pstrFileName, GENERIC_WRITE, 0, NULL,
                       CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);

    if (hFile == INVALID_HANDLE_VALUE)
        return FALSE;

    bSuccess = WriteFile(hFile, pbmfh, pbmfh->bfSize, &dwBytesWritten, NULL);
    CloseHandle(hFile);

    if ((!bSuccess) || (dwBytesWritten != pbmfh->bfSize))
    {
        DeleteFile(pstrFileName);
        return FALSE;
    }
    return TRUE;
}

//resource.h

//{{NO_DEPENDENCIES}}
// Microsoft Visual C++ 生成的包含文件。
// 供 ShowDib1.rc 使用
//
#define IDM_FILE_OPEN                   40001
#define IDM_FILE_SAVE                   40002

// Next default values for new objects
// 
#ifdef APSTUDIO_INVOKED
#ifndef APSTUDIO_READONLY_SYMBOLS
#define _APS_NEXT_RESOURCE_VALUE        103
#define _APS_NEXT_COMMAND_VALUE         40007
#define _APS_NEXT_CONTROL_VALUE         1001
#define _APS_NEXT_SYMED_VALUE           101
#endif
#endif

//ShowDib1.rc

// Microsoft Visual C++ generated resource script.
//
#include "resource.h"

#define APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 2 resource.
//
#include "winres.h"

/////////////////////////////////////////////////////////////////////////////
#undef APSTUDIO_READONLY_SYMBOLS

/////////////////////////////////////////////////////////////////////////////
// 中文(简体,中国) resources

#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_CHS)
LANGUAGE LANG_CHINESE, SUBLANG_CHINESE_SIMPLIFIED

#ifdef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// TEXTINCLUDE
//

1 TEXTINCLUDE
BEGIN
"resource.h\0"
END

2 TEXTINCLUDE
BEGIN
"#include ""winres.h""\r\n"
"\0"
END

3 TEXTINCLUDE
BEGIN
"\r\n"
"\0"
END

#endif    // APSTUDIO_INVOKED


/////////////////////////////////////////////////////////////////////////////
//
// Menu
//

SHOWDIB1 MENU
BEGIN
POPUP "&File"
BEGIN
MENUITEM "&Open...\tCtrl+O", IDM_FILE_OPEN
MENUITEM "&Save...\tCtrl+S", IDM_FILE_SAVE
END
END


/////////////////////////////////////////////////////////////////////////////
//
// Accelerator
//

SHOWDIB1 ACCELERATORS
BEGIN
"^O", IDM_FILE_OPEN, ASCII, NOINVERT
"^S", IDM_FILE_SAVE, ASCII, NOINVERT
END

#endif    // 中文(简体,中国) resources
/////////////////////////////////////////////////////////////////////////////



#ifndef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 3 resource.
//


/////////////////////////////////////////////////////////////////////////////
#endif    // not APSTUDIO_INVOKED
 15.2.3 DIB的颠倒世界

(1)自下而上DIB坐标说明

 

源矩形

目标矩形

①(xSrc,ySrc)—内存中第一个像素!

①(xDst,yDst+cySrc-1)

②(xSrc+cxSrc-1,ySrc)

②(xDst+cxSrc-1,yDst+cySrc-1)

③(xSrc,ySrc+cySrc-1)

③(xDst,yDst)

④(xSrc+cxSrc-1,ySrc+cySrc-1)—内存最后1个像素

④(xDst+cxSrc-1,yDst)

注意:1、cxSrc,cySrc为区域宽度和高度,因为坐标从0开始,所以上面式子出现减1现象。

      2、原点(0,0)位于DIB图的左下角(左图中的①),第一行的第1个像素。

(2)自上而下DIB坐标说明

 

源矩形

目标矩形

①(xSrc,ySrc+cySrc-1)—内存中第1个像素!

①(xDst,yDst)

②(xSrc+cxSrc-1,ySrc+cySrc-1)

②(xDst+cxSrc-1,yDst)

③(xSrc,ySrc)—这里不是第1 个像素!

③(xDst,yDst+cySrc-1)

④(xSrc+cxSrc-1,ySrc)—内存中最后1个像素

④(xDst+cxSrc-1,yDst+cySrc-1)

注意:1、cxSrc,cySrc为区域宽度和高度,因为坐标从0开始,所以上面式子出现减1现象。

      2、原点(0,0)或(xSrc,ySrc)不是DIB图中第1 个像素,也不是最后1个像素,而是③,在图的左下角,即最后一行的第1个像素。

【Apollo11程序】
 效果图
 
/*------------------------------------------------------------
APOLLO11.C -- Program for screen captures
(c) Charles Petzold, 1998
------------------------------------------------------------*/

#include <windows.h>
#include "..\\DibHeads\\DibFile.h"

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

static TCHAR szAppName[] = TEXT("Apollo11");
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
                   PSTR szCmdLine, int iCmdShow)
{
    HWND         hwnd;
    MSG          msg;
    WNDCLASSEX     wndclass;

    wndclass.style = CS_HREDRAW | CS_VREDRAW;
    wndclass.cbSize = sizeof(WNDCLASSEX);
    wndclass.lpfnWndProc = WndProc;
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.hInstance = hInstance;
    wndclass.hIcon = LoadIcon(hInstance, szAppName);
    wndclass.hIconSm = LoadIcon(hInstance, szAppName);
    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndclass.lpszMenuName = NULL;
    wndclass.lpszClassName = szAppName;

    if (!RegisterClassEx(&wndclass))
    {
        MessageBox(NULL, TEXT("This program requires Windows NT!"),
                   szAppName, MB_ICONERROR);
        return 0;
    }

    hwnd = CreateWindow(szAppName,                  // window class name
                        TEXT("Apollo 11"), // window caption
                        WS_OVERLAPPEDWINDOW,        // window style
                        CW_USEDEFAULT,              // initial x position
                        CW_USEDEFAULT,              // initial y position
                        CW_USEDEFAULT,              // initial x size
                        CW_USEDEFAULT,              // initial y size
                        NULL,                       // parent window handle
                        NULL,                       // window menu handle
                        hInstance,                  // program instance handle
                        NULL);                     // creation parameters

    ShowWindow(hwnd, iCmdShow);
    UpdateWindow(hwnd);

    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    HDC         hdc;
    PAINTSTRUCT ps;
    static BITMAPFILEHEADER* pbmfh[2];
    static BITMAPINFO* pbmi[2];
    static BYTE* pBits[2];
    static int cxClient, cyClient, cxDib[2], cyDib[2];

    switch (message)
    {
    case WM_CREATE:
        pbmfh[0] = DibLoadImage(TEXT("Apollo11.bmp"));
        pbmfh[1] = DibLoadImage(TEXT("ApolloTD.bmp"));
        if (pbmfh[0] == NULL || pbmfh[1] == NULL)
        {
            MessageBox(hwnd, TEXT("Cannot load DIB file"), szAppName, 0);
            return 0;
        }

        //获得信息头和像素位指针
        pbmi[0] = (BITMAPINFO*)(pbmfh[0] + 1);
        pbmi[1] = (BITMAPINFO*)(pbmfh[1] + 1);

        pBits[0] = (BYTE*)pbmfh[0] + pbmfh[0]->bfOffBits;
        pBits[1] = (BYTE*)pbmfh[1] + pbmfh[1]->bfOffBits;

        //获取图像大小(为方便,这里只处理BITMAPINFOHEADER结构的DIB)
        cxDib[0] = pbmi[0]->bmiHeader.biWidth;
        cyDib[0] = abs(pbmi[0]->bmiHeader.biHeight);  //绝对值!

        cxDib[1] = pbmi[1]->bmiHeader.biWidth;
        cyDib[1] = abs(pbmi[1]->bmiHeader.biHeight);  //绝对值!
        return 0;

    case WM_SIZE:
        cxClient = LOWORD(lParam);
        cyClient = HIWORD(lParam);
        return 0;

    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);

        //从下到上DIB整图显示
        SetDIBitsToDevice(hdc,
                          0,
                          cyClient / 4, //yDst
                          cxDib[0],   //整幅图宽度
                          cyDib[0],   //整幅图高度
                          0,
                          0,
                          0,          //第一扫描线
                          cyDib[0],   //扫描线数量
                          pBits[0],
                          pbmi[0],
                          DIB_RGB_COLORS);

        //从下到上DIB局部图显示
        SetDIBitsToDevice(hdc,
                          240,
                          cyClient / 4, //yDst
                          80,          //图的局部(宽度)
                          166,         //图的局部(高度)
                          80,          //源的X坐标,在图左下角的附近
                          60,          //源的Y坐标,在图左下角附近
                          0,           //第一扫描线
                          cyDib[0],    //扫描线数量
                          pBits[0],
                          pbmi[0],
                          DIB_RGB_COLORS);

        //从上到下DIB整图显示
        SetDIBitsToDevice(hdc,
                          340,
                          cyClient / 4, //yDst
                          cxDib[1],   //整幅图宽度
                          cyDib[1],   //整幅图高度
                          0,
                          0,
                          0,          //第一扫描线
                          cyDib[1],   //扫描线数量
                          pBits[1],
                          pbmi[1],
                          DIB_RGB_COLORS);

        //从上到下DIB局部图显示
        SetDIBitsToDevice(hdc,
                          580,
                          cyClient / 4, //yDst
                          80,          //图的局部(宽度)
                          166,         //图的局部(高度)
                          80,          //源的X坐标,在图左下角的附近
                          60,          //源的Y坐标,在图左下角附近
                          0,           //第一扫描线
                          cyDib[1],    //扫描线数量
                          pBits[1],
                          pbmi[1],
                          DIB_RGB_COLORS);

        EndPaint(hwnd, &ps);
        return 0;

    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd, message, wParam, lParam);
}
 //DibFile.h和DibFile.C文件见【ShowDib1程序】

 15.2.4 顺序显示——扫描线

(1)SetDIBitsToDevice扫描线的工作原理

SetDIBitsToDevice(hdc,xDst,yDst,cxSrc,cySrc,xSrc,ySrc,yScan,cyScans,pBits,fClrUse);

  ①根据xSrc,ySrc,cxSrc,cySrc确定要显示的源矩形的范围(如图1),再根据xDst,yDst,cxSrc,cySrc确定DIB图像在逻辑坐标系中的输出位置和范围(如图2,用红色虚线框表示的矩形范围)。

  ②为pBits所在数据块按像素行划分出若干条扫描线第1行(也称为第一扫描线)编号为yScan号(一般为0,但这里为了更具普遍性,假设yScan等于20,即第1条扫描线编号为20号),第2条为21号,第3条为22号,以此类推……。直到pBits所有的像素行(或叫扫描线)都编号完毕。本例中DIB位图的高度为240,所以最后一行编号为20+240,即260号。

  ③开始扫描,此时当前扫描线会从A扫描到B。由图中可知,它将扫过从编号60到240的之间范围。假设当前的扫描位置是在编号为70的绿线上。

  ④当在图1中确定好当前扫描线编号以后,再根据当前扫描线的位置,计算出在逻辑坐标系中的输出位置(假设在图2中的绿线位置),而该处输出的数据来自于pBits中扫描线被编号为70号的那行数据,即pBits中第90行的数据。

  ⑤继续扫描其他行,直至AB间的所有像素行都扫描完毕,即结束。

【注意】

  ①本例中,pBits像素的扫描线编号(20-260),但源矩形中只要求输出编号为60至240号的扫描行数据。也就是说,pBits中第40行至220行的数据。所以最终结果如图2所示(要特别注意,源和目标中,显示的图像己经不同了(见红色虚线框内的内容),主要原因是我们将pBits的第1行编号为20,如果编为0(即yScan=0)则显示的内容就会完全相同)。

  ②由于pBits扫描线编号在20-260之间,所以如果当前扫描线要扫描图1中y轴20以下的那些范围,则在pBits中会因找不到对应的扫描线,从而导致那部分的数据在逻辑坐标系中会显示为空白

(2)SetDIBitsToDevice实例分析

 

 【SeqDisp程序】
效果图

/*------------------------------------------------------------
SEQDISP.C -- Sequential Display of DIBs
(c) Charles Petzold, 1998
------------------------------------------------------------*/

#include <windows.h>
#include "resource.h"

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
static TCHAR szAppName[] = TEXT("SeqDisp");

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
                   PSTR szCmdLine, int iCmdShow)
{
    HWND         hwnd;
    MSG          msg;
    WNDCLASSEX   wndclass;
    HACCEL       hAccel;

    wndclass.style = CS_HREDRAW | CS_VREDRAW;
    wndclass.cbSize = sizeof(WNDCLASSEX);
    wndclass.lpfnWndProc = WndProc;
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.hInstance = hInstance;
    wndclass.hIcon = LoadIcon(hInstance, szAppName);
    wndclass.hIconSm = LoadIcon(hInstance, szAppName);
    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndclass.lpszMenuName = szAppName;
    wndclass.lpszClassName = szAppName;

    if (!RegisterClassEx(&wndclass))
    {
        MessageBox(NULL, TEXT("This program requires Windows NT!"),
                   szAppName, MB_ICONERROR);
        return 0;
    }

    hwnd = CreateWindow(szAppName,                  // window class name
                        TEXT("DIB Sequential Display"), // window caption
                        WS_OVERLAPPEDWINDOW,        // window style
                        CW_USEDEFAULT,              // initial x position
                        CW_USEDEFAULT,              // initial y position
                        CW_USEDEFAULT,              // initial x size
                        CW_USEDEFAULT,              // initial y size
                        NULL,                       // parent window handle
                        NULL,                       // window menu handle
                        hInstance,                  // program instance handle
                        NULL);                     // creation parameters

    ShowWindow(hwnd, iCmdShow);
    UpdateWindow(hwnd);
    hAccel = LoadAccelerators(hInstance, szAppName);
    while (GetMessage(&msg, NULL, 0, 0))
    {
        if (!TranslateAccelerator(hwnd, hAccel, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }
    return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    HDC         hdc;
    PAINTSTRUCT ps;
    static BITMAPINFO* pbmi;
    static BYTE* pBits;
    static int cxDib, cyDib, cBits;
    static OPENFILENAME ofn;
    static TCHAR   szFileName[MAX_PATH], szTitleName[MAX_PATH];
    static TCHAR   szFilter[] = TEXT("Bitmap Files(*.BMP)\0*.bmp\0")\
        TEXT("All Files(*.*)\0*.*\0\0");

    BITMAPFILEHEADER  bmfh;
    BOOL bSuccess, bTopDown;
    DWORD dwBytesRead;
    HANDLE hFile;
    int    iInfoSize, iBitsSize, iRowLength;

    switch (message)
    {
    case WM_CREATE:
        ofn.lStructSize = sizeof(OPENFILENAME);
        ofn.hwndOwner = hwnd;
        ofn.hInstance = NULL;
        ofn.lpstrFilter = szFilter;
        ofn.lpstrCustomFilter = NULL;
        ofn.nMaxCustFilter = 0;
        ofn.nFilterIndex = 0;
        ofn.lpstrFile = szFileName;
        ofn.nMaxFile = MAX_PATH;
        ofn.lpstrFileTitle = szTitleName;
        ofn.nMaxFileTitle = MAX_PATH;
        ofn.lpstrInitialDir = NULL;
        ofn.lpstrTitle = NULL;
        ofn.Flags = 0;     //在打开和关闭函数中设置
        ofn.nFileOffset = 0;
        ofn.nFileExtension = 0;
        ofn.lpstrDefExt = TEXT("bmp"); //默认扩展名
        ofn.lCustData = 0;
        ofn.lpfnHook = NULL;
        ofn.lpTemplateName = NULL;
        return 0;

    case WM_COMMAND:
        switch (LOWORD(wParam))
        {
        case IDM_FILE_OPEN:

            //显示打开文件对话框
            if (!GetOpenFileName(&ofn))
                return 0;

            //清除之前打开的位图文件
            if (pbmi)
            {
                free(pbmi);
                pbmi = NULL;
            }

            if (pBits)
            {
                free(pBits);
                pBits = NULL;
            }

            //擦掉客户区上的位图
            InvalidateRect(hwnd, NULL, TRUE);
            UpdateWindow(hwnd); //可注释掉看下

            //打开文件
            hFile = CreateFile(szFileName, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_FLAG_SEQUENTIAL_SCAN, NULL);

            if (hFile == INVALID_HANDLE_VALUE)
            {
                MessageBox(hwnd, TEXT("Cannot open file."), szAppName, MB_ICONWARNING | MB_OK);
                return 0;
            }

            //读取BITMAPFILEHEADER
            bSuccess = ReadFile(hFile, &bmfh, sizeof(BITMAPFILEHEADER), &dwBytesRead, NULL);

            if (!bSuccess || dwBytesRead != sizeof(BITMAPFILEHEADER))
            {
                MessageBox(hwnd, TEXT("Cannot open file."), szAppName, MB_ICONWARNING | MB_OK);
                CloseHandle(hFile);
                return 0;
            }

            //检验是否是位图文件,第1-2个字节为“BM”
            if (bmfh.bfType != *(WORD*)"BM")
            {
                MessageBox(hwnd, TEXT("File is not a bitmap."), szAppName, MB_ICONWARNING | MB_OK);
                CloseHandle(hFile);
                return 0;
            }

            //为文件信息头和像素位数据分配内存
            iInfoSize = bmfh.bfOffBits - sizeof(BITMAPFILEHEADER);
            iBitsSize = bmfh.bfSize - bmfh.bfOffBits;

            pbmi = malloc(iInfoSize);
            pBits = malloc(iBitsSize);

            if (pbmi == NULL || pBits == NULL)
            {
                MessageBox(hwnd, TEXT("Cannot allocate memory."), szAppName, MB_ICONWARNING | MB_OK);
                if (pbmi)
                {
                    free(pbmi);
                    pbmi = NULL;
                }

                if (pBits)
                {
                    free(pBits);
                    pBits = NULL;
                }

                CloseHandle(hFile);
                return 0;
            }

            //读取信息头
            bSuccess = ReadFile(hFile, pbmi, iInfoSize, &dwBytesRead, NULL);
            if (!bSuccess || iInfoSize != dwBytesRead)
            {
                MessageBox(hwnd, TEXT("Cannot allocate memory."), szAppName, MB_ICONWARNING | MB_OK);
                if (pbmi)
                {
                    free(pbmi);
                    pbmi = NULL;
                }

                if (pBits)
                {
                    free(pBits);
                    pBits = NULL;
                }

                CloseHandle(hFile);
                return 0;
            }

            //获取像素数据和高度
            bTopDown = FALSE;
            if (pbmi->bmiHeader.biSize == sizeof(BITMAPCOREHEADER))
            {
                cxDib = ((BITMAPCOREHEADER*)pbmi)->bcWidth;
                cyDib = ((BITMAPCOREHEADER*)pbmi)->bcHeight;
                cBits = ((BITMAPCOREHEADER*)pbmi)->bcBitCount;
            } else
            {
                bTopDown = (pbmi->bmiHeader.biHeight < 0);

                cxDib = pbmi->bmiHeader.biWidth;
                cyDib = abs(pbmi->bmiHeader.biHeight);
                cBits = pbmi->bmiHeader.biBitCount;

                if (pbmi->bmiHeader.biCompression != BI_RGB && pbmi->bmiHeader.biCompression != BI_BITFIELDS)
                {
                    MessageBox(hwnd, TEXT("File is compressed."), szAppName, MB_ICONWARNING | MB_OK);
                    if (pbmi)
                    {
                        free(pbmi);
                        pbmi = NULL;
                    }

                    if (pBits)
                    {
                        free(pBits);
                        pBits = NULL;
                    }

                    CloseHandle(hFile);
                    return 0;
                }
            }

            //计算每行像素宽度,4的倍数
            iRowLength = ((cxDib*cBits + 31)& ~31) >> 3;

            //显示位图
            SetCursor(LoadCursor(NULL, IDC_WAIT));
            ShowCursor(TRUE);

            hdc = GetDC(hwnd);

            for (int y = 0; y < cyDib; y++)
            {
                ReadFile(hFile, pBits + y*iRowLength, iRowLength, &dwBytesRead, NULL);
                /*
                1、每次扫描时,源矩形0,y,cxDib,cyDib-y,目标矩形0,0,cxDib,cyDib-y
                2、每次调用函数时,像素的数据在改变,pBits+y*iRowLength;
                3、每次都为像素位的第一行数据编号为y或cyDib-y-1
                */
                SetDIBitsToDevice(hdc,
                                  0,           //xDst
                                  0,           //yDst
                                  cxDib,       //cxSrc
                                  cyDib - y,     //cySrc,课本这里为cyDib。
                                  0,           //xSrc
                                  y,           //ySrc,课本这里为0,这两处的更改,效率更高
                                  bTopDown ? cyDib - y - 1 : y, //给第一行扫描行编号
                                  1,                          //每次扫描一行
                                  pBits + y*iRowLength,         //第一行扫描行的数据
                                  pbmi,
                                  DIB_RGB_COLORS);
            }

            ReleaseDC(hwnd, hdc);
            CloseHandle(hFile);
            SetCursor(LoadCursor(NULL, IDC_ARROW));
            ShowCursor(FALSE);

            return 0;
        }
        break;
    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);
        if (pbmi && pBits)
        {
            SetDIBitsToDevice(hdc,
                              0,           //xDst
                              0,           //yDst
                              cxDib,       //cxSrc
                              cyDib,      //cySrc
                              0,           //xSrc
                              0,           //ySrc
                              0,           //第一行扫描行编号
                              cyDib,
                              pBits,
                              pbmi,
                              DIB_RGB_COLORS);
        }
        EndPaint(hwnd, &ps);
        return 0;

    case WM_DESTROY:
        if (pbmi)  free(pbmi);

        if (pBits) free(pBits);

        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd, message, wParam, lParam);
}

//resouce.h

//{{NO_DEPENDENCIES}}
// Microsoft Developer Studio generated include file.
// Used by SeqDisp.rc
//
#define IDM_FILE_OPEN                   40001

// Next default values for new objects
// 
#ifdef APSTUDIO_INVOKED
#ifndef APSTUDIO_READONLY_SYMBOLS
#define _APS_NEXT_RESOURCE_VALUE        101
#define _APS_NEXT_COMMAND_VALUE         40002
#define _APS_NEXT_CONTROL_VALUE         1000
#define _APS_NEXT_SYMED_VALUE           101
#endif
#endif

//SeqDisp.rc

//Microsoft Developer Studio generated resource script.
//
#include "resource.h"

#define APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 2 resource.
//
#include "afxres.h"

/////////////////////////////////////////////////////////////////////////////
#undef APSTUDIO_READONLY_SYMBOLS

/////////////////////////////////////////////////////////////////////////////
// English (U.S.) resources

#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_ENU)
#ifdef _WIN32
LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
#pragma code_page(1252)
#endif //_WIN32

#ifdef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// TEXTINCLUDE
//

1 TEXTINCLUDE DISCARDABLE 
BEGIN
    "resource.h\0"
END

2 TEXTINCLUDE DISCARDABLE 
BEGIN
    "#include ""afxres.h""\r\n"
    "\0"
END

3 TEXTINCLUDE DISCARDABLE 
BEGIN
    "\r\n"
    "\0"
END

#endif    // APSTUDIO_INVOKED


/////////////////////////////////////////////////////////////////////////////
//
// Accelerator
//

SEQDISP ACCELERATORS DISCARDABLE 
BEGIN
    "O",            IDM_FILE_OPEN,          VIRTKEY, CONTROL, NOINVERT
END


/////////////////////////////////////////////////////////////////////////////
//
// Menu
//

SEQDISP MENU DISCARDABLE 
BEGIN
    POPUP "&File"
    BEGIN
        MENUITEM "&Open...\tCtrl+O",            IDM_FILE_OPEN
    END
END

#endif    // English (U.S.) resources
/////////////////////////////////////////////////////////////////////////////



#ifndef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 3 resource.
//


/////////////////////////////////////////////////////////////////////////////
#endif    // not APSTUDIO_INVOKED

 

15.2.5 拉伸到合适大小

(1)StretchDIBits函数说明

参数

说明

hdc

设备环境句柄

xDst

目标x坐标

yDst

目标y坐标

cxDst

目标图像的像素宽度(字节),可正可负,实现翻转

cyDst

目标图像的像素高度(字节),可正可负,实现翻转

xSrc

源x坐标(有符号)

ySrc

源y坐标

cxSrc

源图像的像素宽度(字节),可正可负,实现翻转

cySrc

源图像的像素高度(字节),可正可负,实现翻转

pBits

像素位数据

fClrUse

使用颜色标记:DIB_PAL_COLORS或DIB_RGB_COLORS

dwRop

光栅操作

(2)StretchDIBits坐标说明

源矩形

目标矩形

①(xSrc,ySrc)—内存中第一个像素!

①(xDst,yDst+cyDst-1)

②(xSrc+cxSrc-1,ySrc)

②(xDst+cxDst-1,yDst+cyDst-1)

③(xSrc,ySrc+cySrc-1)

③(xDst,yDst)

④(xSrc+cxSrc-1,ySrc+cySrc-1)—内存最后1个像素

④(xDst+cxDst-1,yDst)

注意:1、右列式子出现减1并不准确,因为拉伸和映射模式的影响。

      2、原点(0,0)位于DIB图的左下角(左图中的①),第一行的第1个像素。

(3)判断图像是否上下翻转或左右翻转

if(!Sign(xMM*cxSrc*cxDst))

     DIB沿垂直轴翻转(镜像)

1、xMM为映射模式x从左到右增加,取1,相反取-1。

2、yMM为映射模式y从上到下增加,取1,相反取-1。

if(!Sign(yMM*cySrc*cyDst))

DIB沿水平轴翻转(上下翻转)

【ShowDib2程序】

 

/*------------------------------------------------------------
SHOWDIB2.C -- Shows a DIB in the client area
(c) Charles Petzold, 1998
------------------------------------------------------------*/

#include <windows.h>
#include "resource.h"
#include "..\\ShowDib1\\DibFile.h"

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

static TCHAR szAppName[] = TEXT("ShowDib2");
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
                   PSTR szCmdLine, int iCmdShow)
{
    HWND         hwnd;
    MSG          msg;
    WNDCLASSEX   wndclass;
    HACCEL       hAccel;

    wndclass.style = CS_HREDRAW | CS_VREDRAW;
    wndclass.cbSize = sizeof(WNDCLASSEX);
    wndclass.lpfnWndProc = WndProc;
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.hInstance = hInstance;
    wndclass.hIcon = LoadIcon(hInstance, szAppName);
    wndclass.hIconSm = LoadIcon(hInstance, szAppName);
    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndclass.lpszMenuName = szAppName;
    wndclass.lpszClassName = szAppName;

    if (!RegisterClassEx(&wndclass))
    {
        MessageBox(NULL, TEXT("This program requires Windows NT!"),
                   szAppName, MB_ICONERROR);
        return 0;
    }

    hwnd = CreateWindow(szAppName,                  // window class name
                        TEXT("Show DIB #2"), // window caption
                        WS_OVERLAPPEDWINDOW,        // window style
                        CW_USEDEFAULT,              // initial x position
                        CW_USEDEFAULT,              // initial y position
                        CW_USEDEFAULT,              // initial x size
                        CW_USEDEFAULT,              // initial y size
                        NULL,                       // parent window handle
                        NULL,                       // window menu handle
                        hInstance,                  // program instance handle
                        NULL);                     // creation parameters

    ShowWindow(hwnd, iCmdShow);
    UpdateWindow(hwnd);
    hAccel = LoadAccelerators(hInstance, szAppName);
    while (GetMessage(&msg, NULL, 0, 0))
    {
        if (!TranslateAccelerator(hwnd, hAccel, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }
    return msg.wParam;
}

int ShowDib(HDC hdc, BITMAPINFO* pbmi, BYTE* pBits, int cxDib, int cyDib, int cxClient, int cyClient, WORD wShow)
{
    switch (wShow)
    {
    case IDM_SHOW_NORMAL: //正常显示
        return SetDIBitsToDevice(hdc, 0, 0, cxDib, cyDib, 0, 0, 0, cyDib, pBits, pbmi, DIB_RGB_COLORS);

    case IDM_SHOW_CENTER: //居中显示
        return SetDIBitsToDevice(hdc, (cxClient - cxDib) / 2,
                                 (cyClient - cyDib) / 2,
                                 cxDib, cyDib, 0, 0,
                                 0, cyDib, pBits, pbmi, DIB_RGB_COLORS);
    case IDM_SHOW_STRETCH: //拉伸到整个客户区
        SetStretchBltMode(hdc, COLORONCOLOR); //缩小时,直接去掉颜色值
        return StretchDIBits(hdc, 0, 0, cxClient, cyClient,
                             0, 0, cxDib, cyDib,
                             pBits, pbmi, DIB_RGB_COLORS, SRCCOPY);
    case IDM_SHOW_ISOSTRETCH:
        SetStretchBltMode(hdc, COLORONCOLOR);
        SetMapMode(hdc, MM_ISOTROPIC);
        SetWindowExtEx(hdc, cxDib, cyDib, NULL);
        SetViewportExtEx(hdc, cxClient, cyClient, NULL);
        SetWindowOrgEx(hdc, cxDib / 2, cyDib / 2, NULL);
        SetViewportOrgEx(hdc, cxClient / 2, cyClient / 2, NULL);

        return StretchDIBits(hdc, 0, 0, cxDib, cyDib,  //逻辑坐标系的范围
                             0, 0, cxDib, cyDib,
                             pBits, pbmi, DIB_RGB_COLORS, SRCCOPY);
    }
    return 0;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    static BITMAPFILEHEADER* pbmfh;
    static BITMAPINFO*       pbmi;
    static BYTE*             pBits;

    static TCHAR   szFileName[MAX_PATH], szTitleName[MAX_PATH];
    static int     cxClient, cyClient, cxDib, cyDib;
    HDC    hdc, hdcPrn;
    static DOCINFO   di = { sizeof(DOCINFO), TEXT("ShowDib2:Printing") };
    PAINTSTRUCT ps;
    BOOL         bSuccess;
    int          iEnable, cxPage, cyPage;
    static WORD wShow = IDM_SHOW_NORMAL;
    HMENU hMenu;
    HGLOBAL  hGlobal;
    BYTE     *pGlobal;

    static PRINTDLG  printdlg = { sizeof(PRINTDLG) };


    switch (message)
    {
    case WM_CREATE:

        DibFileInitialize(hwnd);
        return 0;

    case WM_INITMENUPOPUP:
        if (pbmfh)
            iEnable = MF_ENABLED;
        else
            iEnable = MF_GRAYED;

        EnableMenuItem((HMENU)wParam, IDM_FILE_SAVE, iEnable);
        EnableMenuItem((HMENU)wParam, IDM_FILE_PRINT, iEnable);
        EnableMenuItem((HMENU)wParam, IDM_EDIT_CUT, iEnable);
        EnableMenuItem((HMENU)wParam, IDM_EDIT_COPY, iEnable);
        EnableMenuItem((HMENU)wParam, IDM_EDIT_DELETE, iEnable);
        return 0;

    case WM_SIZE:
        cxClient = LOWORD(lParam);
        cyClient = HIWORD(lParam);
        return 0;

    case WM_COMMAND:
        hMenu = GetMenu(hwnd);

        switch (LOWORD(wParam))
        {
        case IDM_FILE_OPEN:
            //显示打开对话框
            if (!DibFileOpenDlg(hwnd, szFileName, szTitleName))
                return 0;

            //如果DIB文件己被载入,释放内存
            if (pbmfh)
            {
                free(pbmfh);
                pbmfh = NULL;
            }

            //将整个DIB加载到内存中
            SetCursor(LoadCursor(NULL, IDC_WAIT));
            ShowCursor(TRUE);

            pbmfh = DibLoadImage(szFileName);

            ShowCursor(FALSE);
            SetCursor(LoadCursor(NULL, IDC_ARROW));

            //使客户区无效,以便后面的绘图并擦除以前客户区显示的内容
            InvalidateRect(hwnd, NULL, TRUE);

            if (pbmfh == NULL)
            {
                MessageBox(hwnd, TEXT("Cannot load DIB file"), szAppName, 0);
                return 0;
            }

            //获取指向DIB信息头的指针和指向像素位的指针
            pbmi = (BITMAPINFO*)(pbmfh + 1);
            pBits = (BYTE*)pbmfh + pbmfh->bfOffBits;

            //获取图像的宽度和高度
            if (pbmi->bmiHeader.biSize == sizeof(BITMAPCOREHEADER))
            {
                cxDib = ((BITMAPCOREHEADER*)pbmi)->bcWidth;
                cyDib = ((BITMAPCOREHEADER*)pbmi)->bcHeight;
            } else
            {
                cxDib = pbmi->bmiHeader.biWidth;
                cyDib = abs(pbmi->bmiHeader.biHeight);
            }
            return 0;

        case IDM_FILE_SAVE:

            //显示保存对话框
            if (!DibFileSaveDlg(hwnd, szFileName, szTitleName))
                return 0;

            //将DIB位图保存到文件中
            SetCursor(LoadCursor(NULL, IDC_WAIT));
            ShowCursor(TRUE);

            bSuccess = DibSaveImage(szFileName, pbmfh);

            ShowCursor(FALSE);
            SetCursor(LoadCursor(NULL, IDC_ARROW));

            if (!bSuccess)
                MessageBox(hwnd, TEXT("Cannot save DIB file"), szAppName, 0);
            return 0;

        case IDM_FILE_PRINT:
            if (!pbmfh)
                return 0;

            //获取打印机DC
            printdlg.Flags = PD_RETURNDC | PD_NOPAGENUMS | PD_NOSELECTION;
            if (!PrintDlg(&printdlg))
                return 0;
            hdcPrn = printdlg.hDC;
            if (NULL == hdcPrn)
            {
                MessageBox(hwnd, TEXT("Cannot obtain Printer DC"),
                           szAppName, MB_ICONEXCLAMATION | MB_OK);
                return 0;
            }

            //检查打印机是否可以打印位图
            if (!(RC_BITBLT)&GetDeviceCaps(hdcPrn, RASTERCAPS))
            {
                DeleteDC(hdcPrn);
                MessageBox(hwnd, TEXT("Printer cannot print bitmaps"),
                           szAppName, MB_ICONEXCLAMATION | MB_OK);
                return 0;
            }

            //获得可打印区域的大小
            cxPage = GetDeviceCaps(hdcPrn, HORZRES);
            cyPage = GetDeviceCaps(hdcPrn, VERTRES);

            bSuccess = FALSE;

            //将位图输程打印机
            SetCursor(LoadCursor(NULL, IDC_WAIT));
            ShowCursor(TRUE);
            //StartDoc、StartPage、EndPage、EndDoc返回值>0说明执行成功。
            if ((StartDoc(hdcPrn, &di)>0) && (StartPage(hdcPrn)>0))
            {
                ShowDib(hdcPrn, pbmi, pBits, cxDib, cyDib, cxPage, cyPage, wShow);
                if (EndPage(hdcPrn)>0)
                {
                    bSuccess = TRUE;
                    EndDoc(hdcPrn);
                }
            }
            ShowCursor(FALSE);
            SetCursor(LoadCursor(NULL, IDC_ARROW));
            DeleteDC(hdcPrn);
            if (!bSuccess)
                MessageBox(hwnd, TEXT("Could not  print bitmap"),
                szAppName, MB_ICONEXCLAMATION | MB_OK);
            return 0;

        case IDM_EDIT_COPY:
        case IDM_EDIT_CUT:
            if (!pbmfh)
                return 0;

            //生成一个紧凑型DIB
            hGlobal = GlobalAlloc(GHND | GMEM_SHARE,
                                  pbmfh->bfSize - sizeof(BITMAPFILEHEADER));
            pGlobal = GlobalLock(hGlobal);
            CopyMemory(pGlobal, (BYTE*)pbmfh + sizeof(BITMAPFILEHEADER),
                       pbmfh->bfSize - sizeof(BITMAPFILEHEADER));
            GlobalUnlock(hGlobal);

            //传输到剪贴板
            OpenClipboard(hwnd);
            EmptyClipboard();
            SetClipboardData(CF_DIB, hGlobal);
            CloseClipboard();

            if (LOWORD(wParam) == IDM_EDIT_COPY)
                return 0;
            //IDM_EDIT_CUT则继续执行下去

        case IDM_EDIT_DELETE:
            if (pbmfh)
            {
                free(pbmfh);
                pbmfh = NULL;
                InvalidateRect(hwnd, NULL, TRUE);
            }

            return 0;

        case IDM_SHOW_CENTER:
        case IDM_SHOW_ISOSTRETCH:
        case IDM_SHOW_NORMAL:
        case IDM_SHOW_STRETCH:
            CheckMenuItem(hMenu, wShow, MF_GRAYED);
            wShow = LOWORD(wParam);
            CheckMenuItem(hMenu, wShow, MF_CHECKED);
            InvalidateRect(hwnd, NULL, TRUE);
            return 0;
        }
        break;

    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);

        if (pbmfh)
        {
            ShowDib(hdc, pbmi, pBits, cxDib, cyDib, cxClient, cyClient, wShow);
        }

        EndPaint(hwnd, &ps);
        return 0;

    case WM_DESTROY:
        if (pbmfh)
            free(pbmfh);
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd, message, wParam, lParam);
}

//resource.h

//{{NO_DEPENDENCIES}}
// Microsoft Visual C++ 生成的包含文件。
// 供 ShowDib2.rc 使用
//
#define IDM_FILE_OPEN                   40001
#define IDM_FILE_SAVE                   40002
#define IDM_FILE_PRINT                  40003
#define IDM_EDIT_CUT                    40004
#define IDM_EDIT_COPY                   40005
#define IDM_EDIT_CLEAR                  40006
#define IDM_EDIT_DELETE                 40007
#define IDM_SHOW_NORMAL                 40008
#define IDM_SHOW_CENTER                 40009
#define IDM_SHOW_STRETCH                40010
#define IDM_SHOW_ISOSTRETCH             40011
// Next default values for new objects
// 
#ifdef APSTUDIO_INVOKED
#ifndef APSTUDIO_READONLY_SYMBOLS
#define _APS_NEXT_RESOURCE_VALUE        103
#define _APS_NEXT_COMMAND_VALUE         40028
#define _APS_NEXT_CONTROL_VALUE         1001
#define _APS_NEXT_SYMED_VALUE           101
#endif
#endif

//ShowDib2.rc

// Microsoft Visual C++ generated resource script.
//
#include "resource.h"
#define APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 2 resource.
//
#include "winres.h"
/////////////////////////////////////////////////////////////////////////////
#undef APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
// 中文(简体,中国) resources
#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_CHS)
LANGUAGE LANG_CHINESE, SUBLANG_CHINESE_SIMPLIFIED
#ifdef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// TEXTINCLUDE
//
1 TEXTINCLUDE
BEGIN
"resource.h\0"
END
2 TEXTINCLUDE
BEGIN
"#include ""winres.h""\r\n"
"\0"
END
3 TEXTINCLUDE
BEGIN
"\r\n"
"\0"
END
#endif    // APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// Menu
//
SHOWDIB2 MENU
BEGIN
POPUP "&File"
BEGIN
MENUITEM "&Open...\tCtrl+O", IDM_FILE_OPEN
MENUITEM "&Save...\tCtrl+S", IDM_FILE_SAVE
MENUITEM SEPARATOR
MENUITEM "&Print\tCtrl+P", IDM_FILE_PRINT
END
POPUP "&Edit"
BEGIN
MENUITEM "Cu&t\tCtrl+X", IDM_EDIT_CUT
MENUITEM "&Copy\tCtrl+C", IDM_EDIT_COPY
MENUITEM "&Delete\tDelete", IDM_EDIT_DELETE
END
POPUP "&Show"
BEGIN
MENUITEM "&Actual Size", IDM_SHOW_NORMAL, CHECKED
MENUITEM "&Center", IDM_SHOW_CENTER
MENUITEM "&Stretch toWindow", IDM_SHOW_STRETCH
MENUITEM "Stretch &Isotropically ", IDM_SHOW_ISOSTRETCH
END
END
/////////////////////////////////////////////////////////////////////////////
//
// Accelerator
//
SHOWDIB2 ACCELERATORS
BEGIN
"^O", IDM_FILE_OPEN, ASCII, NOINVERT
"^S", IDM_FILE_SAVE, ASCII, NOINVERT
"^P", IDM_FILE_PRINT, ASCII, NOINVERT
"^C", IDM_EDIT_COPY, ASCII, NOINVERT
VK_DELETE, IDM_EDIT_DELETE, VIRTKEY, SHIFT, NOINVERT
"^X", IDM_EDIT_CUT, ASCII, NOINVERT
END
#endif    // 中文(简体,中国) resources
/////////////////////////////////////////////////////////////////////////////
#ifndef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 3 resource.
//
/////////////////////////////////////////////////////////////////////////////
#endif    // not APSTUDIO_INVOKED

//DibFile.h和DibFile.c见ShowDib1程序