windows编程 显示图像

在 Windows 编程中显示图像可以使用 GDI+ 库。以下是一个简单的示例代码，它可以加载一张图片并在窗口中显示：

#include <windows.h>
#include <gdiplus.h>
#pragma comment (lib,"Gdiplus.lib")

using namespace Gdiplus;

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) {
    switch (message) {
        case WM_PAINT: {
            PAINTSTRUCT ps;
            HDC hdc = BeginPaint(hwnd, &ps);

            // 创建一个 GDI+ Graphics 对象
            Graphics graphics(hdc);

            // 加载图片
            Image image(L"image.jpg");

            // 显示图片
            graphics.DrawImage(&image, 0, 0);

            EndPaint(hwnd, &ps);
            break;
        }
        case WM_DESTROY:
            PostQuitMessage(0);
            break;
        default:
            return DefWindowProc(hwnd, message, wParam, lParam);
    }
    return 0;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) {
    // 初始化 GDI+
    GdiplusStartupInput gdiplusStartupInput;
    ULONG_PTR gdiplusToken;
    GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);

    // 创建窗口
    HWND hwnd;
    WNDCLASSEX wc;
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = 0;
    wc.lpfnWndProc = WndProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = hInstance;
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wc.lpszMenuName = NULL;
    wc.lpszClassName = L"MyWindowClass";
    wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

    if (!RegisterClassEx(&wc)) {
        MessageBox(NULL, L"Window Registration Failed!", L"Error!", MB_ICONEXCLAMATION | MB_OK);
        return 0;
    }

    hwnd = CreateWindowEx(WS_EX_CLIENTEDGE, L"MyWindowClass", L"Window Title", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 640, 480, NULL, NULL, hInstance, NULL);

    if (hwnd == NULL) {
        MessageBox(NULL, L"Window Creation Failed!", L"Error!", MB_ICONEXCLAMATION | MB_OK);
        return 0;
    }

    // 显示窗口
    ShowWindow(hwnd, nCmdShow);
    UpdateWindow(hwnd);

    // 进入消息循环
    MSG msg;
    while (GetMessage(&msg, NULL, 0, 0) > 0) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    // 关闭 GDI+
    GdiplusShutdown(gdiplusToken);

    return msg.wParam;
}

这个示例代码会创建一个窗口，并在窗口中显示名为 "image.jpg" 的图片。请注意，你需要将图片文件放在可执行文件的同一目录下，并使用正确的文件名。