win32创建一个窗口，创建一个菜单“打开",当点击“打开”菜单项时，弹出非模式对话框，标题为“非模式对话框”，该对话框有一编辑框和一按钮确定，

以下是示例代码：

#include <Windows.h>

// 声明全局变量
HINSTANCE hInst;
HWND hMainWnd;

// 声明函数
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
BOOL CALLBACK DlgProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine, int nCmdShow)
{
    // 初始化全局变量
    hInst = hInstance;

    // 创建主窗口
    WNDCLASSEX wcx = { sizeof(wcx) };
    wcx.style = CS_HREDRAW | CS_VREDRAW;
    wcx.lpfnWndProc = WndProc;
    wcx.hInstance = hInst;
    wcx.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcx.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wcx.lpszClassName = TEXT("MyWindowClass");
    RegisterClassEx(&wcx);

    hMainWnd = CreateWindow(TEXT("MyWindowClass"), TEXT("My Window"),
                            WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT,
                            CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInst, NULL);

    // 创建菜单
    HMENU hMenu = CreateMenu();
    AppendMenu(hMenu, MF_STRING, ID_FILE_OPEN, TEXT("打开"));

    // 将菜单关联到主窗口
    SetMenu(hMainWnd, hMenu);

    // 显示主窗口
    ShowWindow(hMainWnd, nCmdShow);
    UpdateWindow(hMainWnd);

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

    return (int)msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_COMMAND:
        switch (LOWORD(wParam))
        {
        case ID_FILE_OPEN:
            // 弹出非模式对话框
            DialogBox(hInst, MAKEINTRESOURCE(IDD_MYDIALOG), hWnd, DlgProc);
            break;
        }
        break;

    case WM_DESTROY:
        PostQuitMessage(0);
        break;

    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }

    return 0;
}

BOOL CALLBACK DlgProc(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_INITDIALOG:
        SetWindowText(hDlg, TEXT("非模式对话框"));
        return TRUE;

    case WM_COMMAND:
        switch (LOWORD(wParam))
        {
        case IDOK:
            EndDialog(hDlg, IDOK);
            break;

        case IDCANCEL:
            EndDialog(hDlg, IDCANCEL);
            break;
        }
        break;

    default:
        return FALSE;
    }

    return TRUE;
}

其中，`ID_FILE_OPEN`和`IDD_MYDIALOG`是自定义的标识符，需要在资源文件中定义：

#include "resource.h"

ID_FILE_OPEN MENUITEM "打开"
IDC_EDIT1 EDITTEXT 10, 10, 150, 20, WS_BORDER | WS_TABSTOP | ES_AUTOHSCROLL
IDC_BUTTON1 PUSHBUTTON "确定", 10, 40, 75, 25, WS_TABSTOP | WS_VISIBLE | WS_CHILD | BS_DEFPUSHBUTTON

IDD_MYDIALOG DIALOGEX 0, 0, 200, 100, WS_CAPTION | WS_SYSMENU | DS_MODALFRAME | DS_SETFONT, 0, 0, "My Dialog", 9, "MS Shell Dlg", 0
{
    CONTROL "编辑框", IDC_EDIT1, "EDIT", ES_LEFT | ES_AUTOHSCROLL | WS_CHILD | WS_VISIBLE | WS_BORDER | WS_TABSTOP, 10, 10, 150, 20
    CONTROL "确定", IDC_BUTTON1, "BUTTON", BS_PUSHBUTTON | WS_CHILD | WS_VISIBLE | WS_TABSTOP, 10, 40, 75, 25
    CONTROL "取消", IDCANCEL, "BUTTON", BS_PUSHBUTTON | WS_CHILD | WS_VISIBLE | WS_TABSTOP, 95, 40, 75, 25
}

最后，需要在代码中包含资源文件头文件：

#include "resource.h"