vs下Win32对话框程序 怎么让程序一运行在屏幕中间显示

#include <windows.h>
#include "resource.h"
#include <mmsystem.h>
#pragma comment(lib,"winmm.lib")


// 对话框消息处理函数
BOOL CALLBACK DlgProc(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam);

int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine,       int       nShowCmd)
{


    DialogBox(hInstance,MAKEINTRESOURCE(IDD_DIALOG1),NULL,DlgProc);
    LoadIcon(hInstance, MAKEINTRESOURCE(IDI_ICON1));
    return 0;



BOOL CALLBACK DlgProc(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
    RECT       rcDialog;
    HBITMAP    hBitmap;
    static BITMAP s_bm;
    static HDC    s_hdcMem;



    switch (message)
    {
    case WM_COMMAND:
        switch (LOWORD(wParam))
        {
        case IDCANCEL:
            DeleteDC(s_hdcMem);
            EndDialog(hDlg, LOWORD(wParam));
            return TRUE;
        }
        break;

    case WM_SIZE:
        InvalidateRect(hDlg, NULL, TRUE);
        return TRUE;
        break;






    }

    return FALSE;
}