[讨论]一个关屏程序分别用c#.net cf 和 evc++实现的不同

应哥们要求写了个关闭屏幕的小程序，vs.net 2005基于c++实现， 文件大小执行效率都还可以。不过当时写的匆忙很糙的，图标就用默认那个巨难看的！昨天哥们说让我加个图标，我说我用c#重写吧，图标加着方便，于是用C#重写，虽然文件大小只有8K较c++的32K要小很多，但是执行效率非常低下！分析个中原因，大概是因为c++和c#.net程序的执行方式不同造成的吧，c++是传统的执行方式，而.net则是类似于java的解释执行方式，也许在PC上这种差别可以忽略，但是PPC这种对资源敏感的系统差别就出现了。下面是两种语言的实现代码：
c++：

// CloseScreen.cpp : Defines the entry point for the application.
//

#include "stdafx.h"
#include "CloseScreen.h"
#include <windows.h>
#include <commctrl.h>

#define MAX_LOADSTRING 100

// Global Variables:
HINSTANCE   g_hInst;   // current instance
HWND    g_hWndMenuBar;  // menu bar handle

// Forward declarations of functions included in this code module:
ATOM   MyRegisterClass(HINSTANCE, LPTSTR);
BOOL   InitInstance(HINSTANCE, int);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK About(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPTSTR    lpCmdLine,
                   int       nCmdShow)
{
 MSG msg;

 // Perform application initialization:
 if (!InitInstance(hInstance, nCmdShow))
 {
  return FALSE;
 }

 HACCEL hAccelTable;
 hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_CLOSESCREEN));

 // Main message loop:
 while (GetMessage(&msg, NULL, 0, 0))
 {
  if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
  {
   TranslateMessage(&msg);
   DispatchMessage(&msg);
  }
 }

 return (int) msg.wParam;
}

//
//  FUNCTION: MyRegisterClass()
//
//  PURPOSE: Registers the window class.
//
//  COMMENTS:
//
ATOM MyRegisterClass(HINSTANCE hInstance, LPTSTR szWindowClass)
{
 WNDCLASS wc;

 wc.style         = CS_HREDRAW | CS_VREDRAW;
 wc.lpfnWndProc   = WndProc;
 wc.cbClsExtra    = 0;
 wc.cbWndExtra    = 0;
 wc.hInstance     = hInstance;
 wc.hIcon         = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_CLOSESCREEN));
 wc.hCursor       = 0;
 wc.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);
 wc.lpszMenuName  = 0;
 wc.lpszClassName = szWindowClass;

 return RegisterClass(&wc);
}

//
//   FUNCTION: InitInstance(HINSTANCE, int)
//
//   PURPOSE: Saves instance handle and creates main window
//
//   COMMENTS:
//
//        In this function, we save the instance handle in a global variable and
//        create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
    HWND hWnd;
    TCHAR szTitle[MAX_LOADSTRING];  // title bar text
    TCHAR szWindowClass[MAX_LOADSTRING]; // main window class name

    g_hInst = hInstance; // Store instance handle in our global variable

    // SHInitExtraControls should be called once during your application's initialization to initialize any
    // of the device specific controls such as CAPEDIT and SIPPREF.
    SHInitExtraControls();

    LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
    LoadString(hInstance, IDC_CLOSESCREEN, szWindowClass, MAX_LOADSTRING);

    //If it is already running, then focus on the window, and exit
    hWnd = FindWindow(szWindowClass, szTitle); 
    if (hWnd)
    {
        // set focus to foremost child window
        // The "| 0x00000001" is used to bring any owned windows to the foreground and
        // activate them.
        SetForegroundWindow((HWND)((ULONG) hWnd | 0x00000001));
        return 0;
    }

    if (!MyRegisterClass(hInstance, szWindowClass))
    {
     return FALSE;
    }

    hWnd = CreateWindow(szWindowClass, szTitle, WS_VISIBLE,
        CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL);

    if (!hWnd)
    {
        return FALSE;
    }

    // When the main window is created using CW_USEDEFAULT the height of the menubar (if one
    // is created is not taken into account). So we resize the window after creating it
    // if a menubar is present
    if (g_hWndMenuBar)
    {
        RECT rc;
        RECT rcMenuBar;

        GetWindowRect(hWnd, &rc);
        GetWindowRect(g_hWndMenuBar, &rcMenuBar);
        rc.bottom -= (rcMenuBar.bottom - rcMenuBar.top);
  
        MoveWindow(hWnd, rc.left, rc.top, rc.right-rc.left, rc.bottom-rc.top, FALSE);
    }

    ShowWindow(hWnd, nCmdShow);
    UpdateWindow(hWnd);

    return TRUE;
}

//
//  FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
//  PURPOSE:  Processes messages for the main window.
//
//  WM_COMMAND - process the application menu
//  WM_PAINT - Paint the main window
//  WM_DESTROY - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    int wmId, wmEvent;
    PAINTSTRUCT ps;
    HDC hdc;

    static SHACTIVATEINFO s_sai;
 
    switch (message)
    {
        case WM_COMMAND:
            wmId    = LOWORD(wParam);
            wmEvent = HIWORD(wParam);
            // Parse the menu selections:
            switch (wmId)
            {
                case IDM_HELP_ABOUT:
                    DialogBox(g_hInst, (LPCTSTR)IDD_ABOUTBOX, hWnd, About);
                    break;
                case IDM_OK:
                    SendMessage (hWnd, WM_CLOSE, 0, 0);    
                    break;
                default:
                    return DefWindowProc(hWnd, message, wParam, lParam);
            }
            break;
        case WM_CREATE:
            SHMENUBARINFO mbi;

            memset(&mbi, 0, sizeof(SHMENUBARINFO));
            mbi.cbSize     = sizeof(SHMENUBARINFO);
            mbi.hwndParent = hWnd;
            mbi.nToolBarId = IDR_MENU;
            mbi.hInstRes   = g_hInst;

            if (!SHCreateMenuBar(&mbi))
            {
                g_hWndMenuBar = NULL;
            }
            else
            {
                g_hWndMenuBar = mbi.hwndMB;
            }

            // Initialize the shell activate info structure
            memset(&s_sai, 0, sizeof (s_sai));
            s_sai.cbSize = sizeof (s_sai);
            //实现
            keybd_event(VK_OFF, 0, 0, 0); // down
            keybd_event(VK_OFF, 0, 2, 0); // up
           SendMessage(hWnd, WM_CLOSE, 0, 0);

            break;
        case WM_PAINT:
            hdc = BeginPaint(hWnd, &ps);
           
            // TODO: Add any drawing code here...
           
            EndPaint(hWnd, &ps);
            break;
        case WM_DESTROY:
            CommandBar_Destroy(g_hWndMenuBar);
            PostQuitMessage(0);
            break;

        case WM_ACTIVATE:
            // Notify shell of our activate message
            SHHandleWMActivate(hWnd, wParam, lParam, &s_sai, FALSE);
            break;
        case WM_SETTINGCHANGE:
            SHHandleWMSettingChange(hWnd, wParam, lParam, &s_sai);
            break;

        default:
            return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

// Message handler for about box.
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
        case WM_INITDIALOG:
            {
                // Create a Done button and size it. 
                SHINITDLGINFO shidi;
                shidi.dwMask = SHIDIM_FLAGS;
                shidi.dwFlags = SHIDIF_DONEBUTTON | SHIDIF_SIPDOWN | SHIDIF_SIZEDLGFULLSCREEN | SHIDIF_EMPTYMENU;
                shidi.hDlg = hDlg;
                SHInitDialog(&shidi);
            }
            return (INT_PTR)TRUE;

        case WM_COMMAND:
            if (LOWORD(wParam) == IDOK)
            {
                EndDialog(hDlg, LOWORD(wParam));
                return TRUE;
            }
            break;

        case WM_CLOSE:
            EndDialog(hDlg, message);
            return TRUE;

#ifdef _DEVICE_RESOLUTION_AWARE
        case WM_SIZE:
            {
  DRA::RelayoutDialog(
   g_hInst,
   hDlg,
   DRA::GetDisplayMode() != DRA::Portrait ? MAKEINTRESOURCE(IDD_ABOUTBOX_WIDE) : MAKEINTRESOURCE(IDD_ABOUTBOX));
            }
            break;
#endif
    }
    return (INT_PTR)FALSE;
}

C#.net
#region Using directives

using System;
using System.Drawing;
using System.Collections;
using System.Windows.Forms;
using System.Data;
using System.Runtime.InteropServices;

#endregion

namespace CloseScreen
{
    /// <summary>
    /// Summary description for form.
    /// </summary>
    public class Form1 : System.Windows.Forms.Form
    {
        /// <summary>
        /// Main menu for the form.
        /// </summary>
        private System.Windows.Forms.MainMenu mainMenu1;

        public Form1()
        {
            InitializeComponent();
        }

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        protected override void Dispose(bool disposing)
        {
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.mainMenu1 = new System.Windows.Forms.MainMenu();
            //
            // Form1
            //
            this.ClientSize = new System.Drawing.Size(240, 268);
            this.Menu = this.mainMenu1;
            this.Text = "CloseScreen";
            this.Load += new System.EventHandler(this.Form1_Load);

        }

        #endregion

        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        static void Main()
        {
            Application.Run(new Form1());
        }

        [DllImport("coredll.dll")]
        private static extern IntPtr keybd_event(byte bVk, byte bScan, int dwFlags, int dwExtraInfo);

        private void Form1_Load(object sender, EventArgs e)
        {
            //实现
            keybd_event(0xdf, 0, 0, 0); // down
            keybd_event(0xdf, 0, 2, 0); // up
            this.Close();
        }  

    }
}

不过这两个程序我都没有尝试控制台方式，也许控制台方式就没有多大差别了！