gdi高dpi示例.

// 编译命令：
// cl highdpi.cpp /DUNICODE
// cl highdpi.cpp /DUNICODE /DNODPI /Felowdpi
   
// 链接指令
#pragma comment(lib, "kernel32.lib")
#pragma comment(lib, "user32.lib")
#pragma comment(lib, "gdi32.lib")
//#pragma comment(linker, "/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")
   
// 包含文件
#include <windows.h>
   
int g_dpix = 96, g_dpiy = 96;
   
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    PAINTSTRUCT ps;
    HDC hdc;
    HFONT hfont, holdfont;
    TCHAR *str = TEXT("黑体字输出123456ABCDEF示例");
    static HWND hbtn1, hbtn2, hbtn3, hbtn4;
    switch(message)
    {
    case WM_CREATE:
        // 重新设置字体，以应用字体的DPI缩放
        SendMessage(hwnd, WM_SETFONT, (WPARAM)GetStockObject(DEFAULT_GUI_FONT), TRUE);
        // 创建控件，注意DPI缩放方法
        hbtn1 = CreateWindowEx(0, TEXT("BUTTON"), TEXT("按钮一"), WS_CHILD|WS_VISIBLE,
            MulDiv(10, g_dpix, 96), MulDiv(10, g_dpiy, 96),
            MulDiv(90, g_dpix, 96), MulDiv(30, g_dpiy, 96),
            hwnd, (HMENU)1, NULL, NULL);
        hbtn2 = CreateWindowEx(0, TEXT("BUTTON"), TEXT("按钮二"), WS_CHILD|WS_VISIBLE,
            MulDiv(110, g_dpix, 96), MulDiv(10, g_dpiy, 96),
            MulDiv(90, g_dpix, 96), MulDiv(30, g_dpiy, 96),
            hwnd, (HMENU)2, NULL, NULL);
        hbtn3 = CreateWindowEx(0, TEXT("BUTTON"), TEXT("按钮三"), WS_CHILD|WS_VISIBLE,
            MulDiv(210, g_dpix, 96), MulDiv(10, g_dpiy, 96),
            MulDiv(90, g_dpix, 96), MulDiv(30, g_dpiy, 96),
            hwnd, (HMENU)3, NULL, NULL);
        hbtn4 = CreateWindowEx(0, TEXT("BUTTON"), TEXT("按钮四"), WS_CHILD|WS_VISIBLE,
            MulDiv(310, g_dpix, 96), MulDiv(10, g_dpiy, 96),
            MulDiv(90, g_dpix, 96), MulDiv(30, g_dpiy, 96),
            hwnd, (HMENU)4, NULL, NULL);
        // 重新设置字体，以应用字体的DPI缩放
        SendMessage(hbtn1, WM_SETFONT, (WPARAM)GetStockObject(DEFAULT_GUI_FONT), TRUE);
        SendMessage(hbtn2, WM_SETFONT, (WPARAM)GetStockObject(DEFAULT_GUI_FONT), TRUE);
        SendMessage(hbtn3, WM_SETFONT, (WPARAM)GetStockObject(DEFAULT_GUI_FONT), TRUE);
        SendMessage(hbtn4, WM_SETFONT, (WPARAM)GetStockObject(DEFAULT_GUI_FONT), TRUE);
        return 0;
    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);
        // 创建字体，注意字体高度的取值（和Word中相同）和缩放
        hfont = CreateFont(-MulDiv(16, g_dpiy, 72), 0, 0, 0, FW_THIN, FALSE, FALSE, FALSE,
                DEFAULT_CHARSET, OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS,
                DEFAULT_QUALITY, FF_DONTCARE, TEXT("SimHei"));
        holdfont = (HFONT)SelectObject(hdc, hfont);
        // 输出文字，注意起始位置的缩放
        TextOut(hdc, MulDiv(10, g_dpix, 96), MulDiv(50, g_dpiy, 96), str, lstrlen(str));
        // 释放资源
        SelectObject(hdc, holdfont);
        DeleteObject(hfont);
        EndPaint(hwnd, &ps);
        return 0;
    case WM_DESTROY:
        // 退出程序
        PostQuitMessage(0);
        return 0;
    default:
        return DefWindowProc(hwnd, message, wParam, lParam);
    }
}
   
int WINAPI WinMain(HINSTANCE hinst, HINSTANCE, LPSTR, int ncmdshow)
{
    // 关闭DPI缩放
    FARPROC spdpia = GetProcAddress(GetModuleHandle(TEXT("user32")), "SetProcessDPIAware");
#ifndef NODPI
    if (spdpia != NULL) spdpia(); // 去掉这一句可看到DPI缩放效果
#endif
   
    // 获取DPI
    HDC hdc = GetDC(NULL);
    if (hdc != NULL) {
        g_dpix = GetDeviceCaps(hdc, LOGPIXELSX);
        g_dpiy = GetDeviceCaps(hdc, LOGPIXELSY);
        ReleaseDC(NULL, hdc);
    }
   
    // 注册窗口类
    WNDCLASSEX wc = {
        sizeof wc,
        CS_VREDRAW|CS_HREDRAW,
        WndProc,
        0,
        DLGWINDOWEXTRA,
        NULL,
        LoadIcon(NULL, IDI_APPLICATION),
        LoadCursor(NULL, IDC_ARROW),
        (HBRUSH)GetStockObject(WHITE_BRUSH),
        NULL,
        TEXT("MyWndClass"),
        LoadIcon(NULL, IDI_APPLICATION)
    };
    if (!RegisterClassEx(&wc)) return 1;
       
    // 在标题栏显示DPI数值
    TCHAR title[200] = TEXT("");
    wsprintf(title, TEXT("DPI: %d, %d"), g_dpix, g_dpiy);
   
    // 创建窗口，注意DPI缩放方法
    HWND hWnd = CreateWindowEx(0, TEXT("MyWndClass"), title, WS_OVERLAPPEDWINDOW,
            CW_USEDEFAULT, CW_USEDEFAULT,
            MulDiv(500, g_dpix, 96), MulDiv(300, g_dpiy, 96),
            NULL, NULL, NULL, NULL);
   
    // 显示和更新窗口
    ShowWindow(hWnd, ncmdshow);
    UpdateWindow(hWnd);
   
    // 消息循环
    MSG msg;
    while (GetMessage(&msg, 0, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
   
    return (int)msg.wParam;
}