报告鼠标和键盘事件的一个程序（转）

在本章中，我将介绍窗口过程和基本的正文输出，并对一些较高级的题材，如键盘和鼠标，作一个简洁的介绍。消息系统完美的风格使得你可以相对完全地、及时地对这两个硬件设备进行控制。
　　现在，你可以开始输入并运行程序清单 5.1 上的程序。

程序清单 5.1　KeyMouse 程序，用于追踪键盘和鼠标的输入

///////////////////////////////////////
// Program Name:KeyMouse.cpp
// Programer: skyline
// Description: Show how to trap keyboard and mouse input
///////////////////////////////////////

#define STRICT 
#define WIN32_LEAN_AND_MEAN

#include <windows.h>
#include <windowsx.h>
#include <string.h> 
#include <stdio.h>

#pragma warning (disable:4068)
#pragma warning (disable:4100)

//-----------------------------
// Interface
//-----------------------------
                   
// Some variabls

static int Xval=10;
static int Yval=30;
static char szAppName[]="KeyMouse";
static HWND MainWindow;          

// Some procs

LRESULT CALLBACK WndProc(HWND hwnd,UINT Message,
         WPARAM wParam,LPARAM lParam);
BOOL Register(HINSTANCE hInst);
HWND Create(HINSTANCE hInst,int nCmdShow);

#define skyline_DefProc DefWindowProc

void skyline_OnDestroy(HWND hwnd);
void skyline_OnChar(HWND hwnd,UINT ch,int cRepeat);
void skyline_OnKey(HWND hwnd,UINT vk,BOOL fDown,
       int cRepeat,UINT flags);
void skyline_OnLButtonDown(HWND hwnd,BOOL fDoubleCick,
       int x,int y,UINT KeyFlags);
void skyline_OnLButtonUp(HWND hwnd,int x,int y,UINT KeyFlags);
void skyline_OnMouseMove(HWND hwnd,int x,int y,UINT KeyFlags);
void skyline_OnPaint(HWND hwnd);
void skyline_OnSysKey(HWND hwnd,UINT vk,BOOL fDown,
       int cRepeat,UINT flags);

//-----------------------
// Initalization
//-----------------------

///////////////////////////
// Program entry point.
///////////////////////////

#pragma argsused                                         
                                         
int WINAPI WinMain(HINSTANCE hInst,HINSTANCE hPrevInstance,
       LPSTR lpszCmdParam,int nCmdShow)
{
    MSG Msg;

    if (! hPrevInstance)
 if (! Register(hInst)) 
     return FALSE; 

    MainWindow = Create(hInst,nCmdShow);
    if(! MainWindow)
 return FALSE;

    while(GetMessage(&Msg,NULL,0,0))
    {
 TranslateMessage(&Msg);
 DispatchMessage(&Msg);              
    }
    return Msg.wParam;
}

////////////////////////////////////
// Register the window
////////////////////////////////////

BOOL Register(HINSTANCE hInst)
{
    WNDCLASS WndClass;

    WndClass.style = CS_HREDRAW|CS_VREDRAW|CS_DBLCLKS;
    WndClass.lpfnWndProc = WndProc;
    WndClass.cbClsExtra = 0;
    WndClass.cbWndExtra = 0;
    WndClass.hInstance = hInst;
    WndClass.hIcon = LoadIcon(NULL,IDI_APPLICATION);
    WndClass.hCursor = LoadCursor(NULL,IDC_ARROW);
    WndClass.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
    WndClass.lpszMenuName = NULL;
    WndClass.lpszClassName = szAppName;

    return RegisterClass(&WndClass);
}

////////////////////////////////////
// Create the Window
////////////////////////////////////

HWND Create(HINSTANCE hInstance,int nCmdShow)
{
    HWND hwnd = CreateWindowEx (0,szAppName,szAppName,
 WS_OVERLAPPEDWINDOW,
 CW_USEDEFAULT,CW_USEDEFAULT,
 CW_USEDEFAULT,CW_USEDEFAULT,
 NULL,NULL,hInstance,NULL);
    if(hwnd == NULL)
 return hwnd;

    ShowWindow(hwnd,nCmdShow);
    UpdateWindow(hwnd);

    return hwnd;
}
                
//----------------------------
// WndProc and Implementation
//----------------------------

//////////////////////////////////
// The WindowProcedured
//////////////////////////////////
 
LRESULT CALLBACK WndProc(HWND hwnd,UINT Message,
 WPARAM wParam,LPARAM lParam)  
{ 
    switch(Message)
    {
   HANDLE_MSG(hwnd,WM_DESTROY,skyline_OnDestroy);
   HANDLE_MSG(hwnd,WM_CHAR,skyline_OnChar);
   HANDLE_MSG(hwnd,WM_KEYDOWN,skyline_OnKey);
   HANDLE_MSG(hwnd,WM_KEYUP,skyline_OnKey);
   HANDLE_MSG(hwnd,WM_MOUSEMOVE,skyline_OnMouseMove);
  HANDLE_MSG(hwnd,WM_LBUTTONDBLCLK,skyline_OnLButtonDown);
   HANDLE_MSG(hwnd,WM_LBUTTONDOWN,skyline_OnLButtonDown);
   HANDLE_MSG(hwnd,WM_LBUTTONUP,skyline_OnLButtonUp);
   HANDLE_MSG(hwnd,WM_PAINT,skyline_OnPaint);
   HANDLE_MSG(hwnd,WM_SYSKEYUP,skyline_OnSysKey);
   HANDLE_MSG(hwnd,WM_SYSKEYDOWN,skyline_OnSysKey);

      default:
   return skyline_DefProc(hwnd,Message,wParam,lParam);
    }
}

///////////////////////////////////////
// Handle WM_DESTROY
///////////////////////////////////////

#pragma argsused
void skyline_OnDestroy(HWND hwnd)
{
    PostQuitMessage(0);
}
           
///////////////////////////////////////
// Handle regular keyboard hits
// Use if you want to trap the letter keys or number keys.
///////////////////////////////////////

#pragma argsused
void skyline_OnChar(HWND hwnd,UINT ch,int cRepeat)
{
    char S[100];
 
    HDC DC = GetDC(hwnd);

    sprintf(S,"WM_CHAR ==> Char = %c  cRepeat = %d         ",
 ch,cRepeat);
    TextOut(DC,Xval,Yval+20,S,strlen(S));

    ReleaseDC(hwnd,DC);
}

///////////////////////////////////////
// Handle a key press
// Don't try to process letter keys or number keys here.
// Instead, ues WM_CHAR messages.
///////////////////////////////////////

#pragma argsused
void skyline_OnKey(HWND hwnd,UINT vk,BOOL fDown,
 int cRepeat,UINT flags)
{
    char S[100];

    HDC DC = GetDC(hwnd);
     
    if(fDown)       
 sprintf(S,"WM_KEYDOWN ==> VK = %d  fDown = %d  cRepeat = %d  "
     "Flags = %d         ",vk,fDown,cRepeat,flags);
    else
 sprintf(S,"WM_KEYUP ==> VK = %d  fDown = %d  cRepeat = %d  "
      "Flags = %d         ",vk,fDown,cRepeat,flags);

    SetBkColor(DC,GetSysColor(COLOR_WINDOW));
    TextOut(DC,Xval,Yval+40,S,strlen(S));

    ReleaseDC(hwnd,DC);
}

///////////////////////////////////////
// This function is called when the left mouse button is
// click or when the user double-clicks the mouse
///////////////////////////////////////

#pragma argsused
void skyline_OnLButtonDown(HWND hwnd,BOOL fDoubleClick,
 int x,int y,UINT KeyFlags)
{
    char S[100];

    HDC DC = GetDC(hwnd);
     
    if(fDoubleClick)       
 sprintf(S,"WM_LBUTTONDBLCLK ==> DblClk = %d  X = %d  Y = %d  "
      "Flags = %d         ",fDoubleClick,x,y,KeyFlags);
    else
 sprintf(S,"WM_LBUTTONDOWN ==> Down = %d  X = %d  Y = %d  "
      "Flags = %d         ",fDoubleClick,x,y,KeyFlags);

    SetBkColor(DC,GetSysColor(COLOR_WINDOW));
    TextOut(DC,Xval,Yval+100,S,strlen(S));

    ReleaseDC(hwnd,DC);
}

///////////////////////////////////////
// This function is called when the mouse button is released
///////////////////////////////////////

#pragma argsused
void skyline_OnLButtonUp(HWND hwnd,int x,int y,UINT KeyFlags)
{
    char S[100];

    HDC DC = GetDC(hwnd);
     
    sprintf(S,"WM_LBUTTONUP ==> X = %d  Y = %d  "
  "Flag = %d         ",x,y,KeyFlags);

    SetBkColor(DC,GetSysColor(COLOR_WINDOW));
    TextOut(DC,Xval,Yval+120,S,strlen(S));

    ReleaseDC(hwnd,DC);
}

///////////////////////////////////////
// This function is called whenever the mouse moves
///////////////////////////////////////

#pragma argsused
void skyline_OnMouseMove(HWND hwnd,int x,int y,UINT KeyFlags)
{
    char S[100];

    HDC DC = GetDC(hwnd);
     
    sprintf(S,"WM_MOUSEMOVE ==> X = %d  Y = %d  "
  "KeyFlags = %d         ",x,y,KeyFlags);

    if((KeyFlags & MK_CONTROL) == MK_CONTROL)
  SetTextColor(DC,RGB(0,0,255));
    if((KeyFlags & MK_LBUTTON) == MK_LBUTTON)
  SetTextColor(DC,RGB(0,128,0));
    if((KeyFlags & MK_RBUTTON) == MK_RBUTTON)
  SetTextColor(DC,RGB(152,84,95));
    if((KeyFlags & MK_SHIFT) == MK_SHIFT)
  SetTextColor(DC,RGB(196,0,196));

    SetBkColor(DC,GetSysColor(COLOR_WINDOW));
    TextOut(DC,Xval,Yval+80,S,strlen(S));

    ReleaseDC(hwnd,DC);
}

///////////////////////////////////////
// Handle WM_PAINT messages
///////////////////////////////////////

void skyline_OnPaint(HWND hwnd)
{
    PAINTSTRUCT PaintStruct;
    RECT Rect;

    static char * Message[] =
    {
 "WM_CHAR",
 "WM_KEY",
 "WM_SYSKEY",
 "WM_MOUSEMOVE",
 "WM_MOUSEDOWN",
 "WM_MOUSEUP"
    };
 
    HDC PaintDC = BeginPaint(hwnd,&PaintStruct);

    SetBkColor(PaintDC,GetSysColor(COLOR_WINDOW));
    HFONT OldFont = SelectFont(PaintDC,
  GetStockObject(OEM_FIXED_FONT));
 
    GetClientRect(hwnd,&Rect);
    Rect.top = 5;
    DrawText(PaintDC,"Mouse and Keyboard Demonstration",-1,
  &Rect,DT_CENTER);
    Rect.top = 20;
    Rect.bottom = 40;
    DrawText(PaintDC,"Try experimenting with mouse and keyboard.",-1,
  &Rect,DT_CENTER);

    SelectFont(PaintDC,OldFont);

    for(int i=0;i<6;i++)
  TextOut(PaintDC,Xval,Yval+(20*(i+1)),
  Message[i],strlen(Message[i]));
 
    EndPaint(hwnd,&PaintStruct);
}

///////////////////////////////////////
// This function is called whenever the ALT key is pressed.
///////////////////////////////////////

#pragma argsused
void skyline_OnSysKey(HWND hwnd,UINT vk,BOOL fDown,
 int cRepeat,UINT flags)
{
    char S[100];
 
    HDC DC = GetDC(hwnd);
    SetBkColor(DC,GetSysColor(COLOR_WINDOW));
     
    if(fDown)
    {
 sprintf(S,"WM_SYSKEYDOWN ==> VK = %d  fDown = %d  "
       "cRepeat = %d         ",vk,fDown,cRepeat,flags);
 TextOut(DC,Xval,Yval+60,S,strlen(S));
 FORWARD_WM_SYSKEYUP(hwnd,vk,cRepeat,flags,skyline_DefProc);
    }
    else
    {
 sprintf(S,"WM_SYSKEYUP ==> VK = %d  fDown = %d  "
       "cRepeat = %d         ",vk,fDown,cRepeat,flags);
 TextOut(DC,Xval,Yval+60,S,strlen(S));
 FORWARD_WM_SYSKEYUP(hwnd,vk,cRepeat,flags,skyline_DefProc);
    }

    ReleaseDC(hwnd,DC);
}

KeyMouse 程序提供两种主要的服务：
　　·如何检测一个键被按下，并且显示按下键的键值以及一些相关的信息。
　　·如何检测鼠标的移动或鼠标是否被按下，并在屏幕上显示出鼠标的当前位置及状态。
　　你可以花几分钟运行一下这个程序。当你移动鼠标或者按下键盘时，注意屏幕窗口上的反应。还要记住，每当你按下 Alt 键时，位于标题栏左上方的系统菜单就会被激活。此时若按一般的键都不会使屏幕恢复原样，除非再次按下 Alt 键或者采取其他动作改变焦点(focus)。有关检测 Alt 键按下动作的讨论在论述 WM_SYSKEY 消息一节中进行。

　　附注：
　　在 Windows 程序设计中，焦点的概念是很重要的。只有被聚焦的窗口才会响应键盘和鼠标的输入，而没有被聚焦的窗口是不响应的。你经常可以知道哪一个特定程序处于焦点，只要检查一下它的标题栏是否为高亮度显示就可以了。

　　同样十分重要的是要理解一个时刻只有一个窗口处于聚焦状态。例如，如果你打开 File 菜单，那么这个新打开的菜单处于焦点位置，而程序的主窗口就处于非活动状态。同样，在 My Computer 窗口中，当从 View 菜单中弹出 Options 对话框时，这个对话框是焦点，而 My Computer 窗口的其它部分是不活动的。