win32 显示 bmp文件

win32 显示 bmp文件

用vs2013 创建一个win32 应用程序，空项目，项目名称是HelloBitmap

拷贝下图的bmp格式文件 abc.bmp 到项目文件所在目录:

添加一个bitmap资源：

进入 资源视图 模式

保存一下：

进入 解决方案资源管理器 模式
在源文件中添加文件：HelloBitmap.cpp
内容如下：

#include <windows.h>
#include <stdlib.h>                                                 
#include <string.h>                                                 
#include <tchar.h>                                                  
#include "resource.h"          

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

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

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

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

    hwnd = CreateWindow(szAppName,                  // window class name
        TEXT("The Hello Program"), // 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;
    HDC         hdcMem;

    PAINTSTRUCT ps;
    HINSTANCE      hInstance;
    BITMAP         bitmap;

    static HBITMAP hBitmap;                  // 1 静态变量

    static int      bmWidth, bmHeight;       // 2 静态变量

    switch (message)
    {

    case WM_CREATE:

        hInstance = ((LPCREATESTRUCT)lParam)->hInstance;                 // 3

        hBitmap = LoadBitmap(hInstance, MAKEINTRESOURCE(IDB_BITMAP1));   // 4

        GetObject(hBitmap, sizeof (BITMAP), &bitmap);                    // 5

        bmWidth = bitmap.bmWidth;                                        // 6

        bmHeight = bitmap.bmHeight;                                      // 7

        break;

    case WM_PAINT:

        hdc = BeginPaint(hwnd, &ps);                                     // 8

        hdcMem = CreateCompatibleDC(hdc);                                // 9

        SelectObject(hdcMem, hBitmap);                                   // 10

        BitBlt(hdc, 0, 0, bmWidth, bmHeight, hdcMem, 0, 0, SRCCOPY);     // 11 显示位图  

        DeleteDC(hdcMem);                                                // 12

        EndPaint(hwnd, &ps);                                             // 13

        break;

    case WM_CLOSE:

        DestroyWindow(hwnd);

        break;

    case WM_DESTROY:

        DeleteObject(hBitmap);                          // 14 

        PostQuitMessage(0);

        break;

    default:

        return DefWindowProc(hwnd, message, wParam, lParam);

    }

    return 0;
}

编译运行，效果如下：

注意代码中的 带有 // 的语句，尤其是//1 ，//2 和 //14