走进windows编程的世界-----消息处理函数（2）

一 WM_PAINT消息

1 WM_PAINT的产生
   因为窗体的互相覆盖等,产生须要绘制的区域,那么会产生WM_PAINT消息.
   普通情况下,不直接发送WM_PAINT消息,通过API声明须要绘制区域,来产生WM_PAINT消息.
   比如,能够使用InvalidateRect声明一个须要又一次绘制的区域.
  
  2 WM_PAINT的注意点
    2.1 假设一个消息队列中,有多个WM_PAINT消息,仅仅有最后一个WM_PAINT消息会被处理.
    2.2 WM_PAINT消息处理中,要清空须要被绘制的区域. BeginPaint
      
  3 WM_PAINT的使用
    3.1 WM_PAINT開始时,必须调用BeginPaint
    3.2 绘制图形
    3.3 WM_PAINT处理后,必须调用EndPaint

看以下的演示样例代码：

/* File : winpaint.cpp
 * Auth : sjin
 * Date : 20140706
 * Mail : 413977243@qq.com
 */

#include <Windows.h>
#include <stdio.h>

HINSTANCE g_hInst = NULL;

void OnPaint(HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam)
{
    PAINTSTRUCT ps = {0};
	/*WM_PAINT開始时。必须调用的*/
    HDC hDC = BeginPaint(hWnd, &ps);

    CHAR szText[] = "Hello WM_PAINT";
	/*在指定的坐标下输出一行字*/
    TextOut(hDC, 100, 100, szText, strlen(szText));

	/*绘制一个矩形*/
    Rectangle(hDC, 200, 200, 300, 300);

	EndPaint(hWnd,&ps);
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam)
{
    switch(nMsg)
    {
    case WM_PAINT:
        OnPaint(hWnd, nMsg, wParam, lParam);
		break;
    case WM_DESTROY:
        PostQuitMessage(0);
		return 0;
    }
    return DefWindowProc(hWnd, nMsg, wParam, lParam);
}

BOOL RegisterWnd(LPSTR lpszClassName)
{
    WNDCLASSEX wce = {0};
    wce.cbClsExtra = 0;
    wce.cbSize = sizeof(wce);
    wce.cbWndExtra = 0;
    wce.hbrBackground = HBRUSH(COLOR_BTNFACE + 1);
    wce.hCursor = NULL;
    wce.hIcon = NULL;
    wce.hIconSm = NULL;
    wce.hInstance = g_hInst;
    wce.lpfnWndProc = WndProc;
    wce.lpszClassName = lpszClassName;
    wce.lpszMenuName = NULL;
    wce.style = CS_HREDRAW|CS_VREDRAW;

    ATOM nAtom = RegisterClassEx(&wce);
    if(0 == nAtom)
    {
        return FALSE;
    }
    return TRUE;
}

HWND CreateWnd(LPSTR lpszClassName)
{
    HWND hWnd = CreateWindowEx(0,
        lpszClassName, "MyWndPaint", WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
        NULL, NULL, g_hInst, NULL);
    return hWnd;
}

void DisplayWnd(HWND hWnd)
{
    ShowWindow(hWnd, SW_SHOW);
    UpdateWindow(hWnd);
}

void Message()
{
    MSG msg = {0};
    while(GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
}

int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
     g_hInst = hInstance;
    RegisterWnd("MyWndPaint");
    HWND hWnd = CreateWnd("MyWndPaint");
    DisplayWnd(hWnd);
    Message();
    return 0;
}

三 键盘消息

1 键盘消息
   按键消息
     WM_KEYDOWN 当键被按下时产生
     WM_KEYUP 当键被释放时产生
     WM_SYSKEYDOWN 当系统键被按下时产生 ALT/F10
     WM_SYSKEYUP 当系统键释放时产生
    字符消息
     WM_CHAR 当有字符键被按下时产生
      TranslateMessage会将WM_KEYDOWN消息中,能够显示的按键,转换成WM_CHAR的消息
  2 消息參数
    WPARAM - 虚拟键码
    LPARAM - 相关的按键信息.
  
  3 消息的使用
    3.1 当有按键消息时,首先进入系统消息队列,然后被程序的消息循环获取.
    3.2 消息的处理
  4 键盘消息的顺序
    对于可显示字符: WM_KEYDOWN,WM_CHAR,WM_KEYUP
    对于不可显示字符: WM_KEYDOWN,WM_KEYUP
    对于系统键:WM_SYSKEYDOWN,WM_SYSKEYUP
    假设按键一直不释放,会反复产生
         WM_KEYDOWN(WM_CHAR)

/* File : winKeyboard.cpp
 * Auth : sjin
 * Date : 2014-07-06
 * Mail : 413977243@qq.com
 */

#include <Windows.h>
#include <stdio.h>

HINSTANCE g_hInst = NULL;
HANDLE g_hStdOut = NULL;

LRESULT CALLBACK WinProc(HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam)
{
    switch(nMsg)
    {
    case WM_KEYDOWN:/*键盘按下*/
        {
            CHAR szText[] = "WM_KEYDOWN\n";
            switch(wParam)
            {
            case VK_LEFT:
            case VK_RIGHT:
            case VK_UP:
            case VK_DOWN:
                WriteConsole(g_hStdOut, szText, strlen(szText), NULL, NULL);
                break;
            }
        }
        break;
    case WM_KEYUP:/*键盘抬起*/
        {
            CHAR szText[] = "WM_KEYUP\n";
            WriteConsole(g_hStdOut, szText, strlen(szText), NULL, NULL); break;
        }
        break;
    case WM_SYSKEYDOWN:/*系统键按下*/
        {
            CHAR szText[] = "WM_SYSKEYDOWN\n";
            WriteConsole(g_hStdOut, szText, strlen(szText), NULL, NULL); break;
        }
        break;
    case WM_SYSKEYUP:/*系统键抬起*/
        {
            CHAR szText[] = "WM_SYSKEYUP\n";
            WriteConsole(g_hStdOut, szText, strlen(szText), NULL, NULL); break;
        }
        break;
    case WM_CHAR:/*字符键盘*/
        {
            CHAR szText[260] = {0};
            sprintf(szText, "WM_CHAR: %c\n", wParam);
            WriteConsole(g_hStdOut, szText, strlen(szText), NULL, NULL); break;
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0); return 0;
    }
    return DefWindowProc(hWnd, nMsg, wParam, lParam);
}

BOOL ResiterWnd(LPSTR lpszClassName)
{
    WNDCLASSEX wce = {0};
    wce.cbClsExtra = 0;
    wce.cbSize = sizeof(wce);
    wce.cbWndExtra = 0;
    wce.hbrBackground = HBRUSH(COLOR_BTNFACE+1);
    wce.hCursor = NULL;
    wce.hIcon = NULL;
    wce.hIconSm = NULL;
    wce.hInstance = g_hInst;
    wce.lpfnWndProc = WinProc;
    wce.lpszClassName = lpszClassName;
    wce.lpszMenuName = NULL;
    wce.style = CS_HREDRAW|CS_VREDRAW;

    ATOM nAtom = RegisterClassEx(&wce);
    if(0==nAtom)
    {
        return FALSE;
    }
    return TRUE;
}

HWND CreateWnd(LPSTR lpszClassName)
{
    HWND hWnd = CreateWindowEx(0, lpszClassName, "MyWnd",
        WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,CW_USEDEFAULT,
        NULL, NULL, g_hInst, NULL);
    return hWnd;
}

void ShowWnd(HWND hWnd)
{
    ShowWindow(hWnd, SW_SHOW);
    UpdateWindow(hWnd);
}

void Message()
{
    MSG msg = {0};
    while(GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
}

void NewConsole()
{
	/*产生控制台*/
    AllocConsole();

	/*获得控制台标准输出流句柄*/
    g_hStdOut = GetStdHandle(STD_OUTPUT_HANDLE);
    CHAR szText[] = "Debug Message......:\n";
	/*将szText 写到控制台*/
    WriteConsole(g_hStdOut, szText, strlen(szText), NULL, NULL);
}

int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
	/*产生命令行窗体。用来调试程序*/
    NewConsole();
     g_hInst = hInstance;
    ResiterWnd("MyWnd");
    HWND hWnd = CreateWnd("MyWnd");
    ShowWnd(hWnd);
    Message();

    return 0;
}

三  鼠标消息

1 鼠标消息
    1) 基本鼠标消息
    WM_LBUTTONDOWN   左键按下
    WM_LBUTTONUP     左键抬起
    WM_RBUTTONDOWN   右键按下
    WM_RBUTTONUP     右键抬起
    WM_MOUSEMOVE     鼠标移动
    2) 双击消息
    WM_LBUTTONDBLCLK 左键双击 
    WM_RBUTTONDBLCLK 右键双击
    3) 滚轮消息
    WM_MOUSEWHEEL    鼠标滚轮

2 消息的參数
    WPARAM - 当前键盘和鼠标按键状态，比如MK_CONTROL/MK_SHIFT,MK_LBUTTON等
    LPARAM - 当前鼠标的坐标,坐标的原点是窗体客户区的左上角.
       X坐标 - LOWORD(lParam),低16位
       Y坐标 - HIWORD(lParam),高16位
    參数详细内容和详细鼠标消息有略微不同. 
    
  3 消息的使用
  
    3.1 基本鼠标消息,仅仅需在窗体处理函数添加消息处理就可以. 当消息来临,获取鼠标和按键状态.比如:

case WM_MOUSEMOVE:
{
    int nX = LOWORD(lParam);
    int nY = HIWORD(lParam);
}

附:坐标转换的函数 ClientToScreen能够将鼠标坐标转换为屏幕的坐标.

3.2 双击消息
   3.2.1 窗体注冊要添加 CS_DBLCLKS 类型
    wce.style = CS_DBLCLKS|...;
   3.2.2 在窗体处理函数中添加消息处理
   3.2.3 产生过程,比如:WM_LBUTTONDBLCLK
      WM_LBUTTONDOWN
      WM_LBUTTONUP
      WM_LBUTTONDBLCLK
      WM_LBUTTONUP
      连续两次LBUTTONDOWN的时间间隔小于预定的双击时间间隔,就会产生LBUTTONDBLCLK消息. 
      双击时间间隔能够通过控制面板调整.

3.3 滚轮消息
  3.3.1 因为WM_MOUSEWHEEL须要Winnt4.0以上版本号支持,所以须要包括在windows.h的头文件前,添加 _WIN32_WINNT 宏定义,
        #define _WIN32_WINNT 0x0400
    3.3.2 在窗体处理函数中添加消息处理
    3.3.3 參数
     LPARAM 与其他鼠标消息类同
     WPARAM - LOWORD(WPARAM) 表示按键状态
              HIWORD(WPARAM) 滚轮滚动幅度,
                120的倍数,能够为正负值.
        正值: 滚轮向上滚动, 一般窗体向上滚动
        负值: 滚轮向下滚动, 一般窗体向下滚动

/* File : winCursor.cpp
 * Auth : sjin
 * Date : 2014-07-06
 * Mail : 413977243@qq.com
 */

#include <Windows.h>
#include <stdio.h>

int g_nXPos = 0;
int g_nYPos = 0;
int g_nX1Rect = 0;
int g_nY1Rect = 0;
int g_nX2Rect = 0;
int g_nY2Rect = 0;

HINSTANCE g_hInst   = NULL;
HANDLE    g_hStdOut = NULL;

void PrintLog(LPSTR lpszLog)
{
    WriteConsole(g_hStdOut, lpszLog, strlen(lpszLog), NULL, NULL);
}

void OnPaint(HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam)
{
    PAINTSTRUCT ps = {0};
    HDC hDC = BeginPaint(hWnd, &ps);
    CHAR szText[] = "Hello Mouse 12123";
    TextOut(hDC, g_nXPos, g_nYPos, szText, strlen(szText));

    Rectangle(hDC, g_nX1Rect, g_nY1Rect, g_nX2Rect, g_nY2Rect);
    EndPaint(hWnd, &ps);
}

LRESULT CALLBACK WndProc( HWND hWnd,
                          UINT nMsg,
                          WPARAM wParam,
                          LPARAM lParam )
{
    switch( nMsg )
    {
    case WM_PAINT:
        OnPaint(hWnd, nMsg, wParam, lParam); break;
    case WM_LBUTTONDOWN:/*鼠标左键按下*/
        {
            PrintLog("WM_LBUTTONDOWN\n");
            g_nX1Rect = LOWORD(lParam);
            g_nY1Rect = HIWORD(lParam);
        }
        break;
    case WM_LBUTTONUP:/*鼠标左键抬起*/
        {
            PrintLog("WM_LBUTTONUP\n");
            g_nX2Rect = LOWORD(lParam);
            g_nY2Rect = HIWORD(lParam);
			/*窗体更新区域加入一个矩形。背景将会擦出
			 * 会触发WM_PAINT消息。
			 */
            InvalidateRect(hWnd, NULL, TRUE);
        }
        break;
    case WM_RBUTTONDOWN:/*鼠标右键按下*/
        PrintLog("WM_RBUTTONDOWN\n");
        break;
    case WM_RBUTTONUP:/*鼠标右键抬起*/
        PrintLog("WM_RBUTTONUP\n");
        break;
    case WM_MOUSEMOVE:/*鼠标移动*/
        {
            int nX = LOWORD(lParam);
            int nY = HIWORD(lParam);
            POINT ptScreen = {0};
            ptScreen.x = nX;
            ptScreen.y = nY;
			/*函数将指定点，或者矩形的用户坐标转换成屏幕坐标*/
            ClientToScreen(hWnd, &ptScreen);

            CHAR szText[260] = { 0 };
            sprintf( szText,
                "WM_MOUSEMOVE: X=%d(%d),Y=%d(%d)\n",
                nX, ptScreen.x, nY, ptScreen.y );
            PrintLog( szText );
            if( wParam & MK_CONTROL )
            {
                PrintLog( "WM_MOUSEMOVE: MK_CONTROL\n" );
            }
            if( wParam & MK_LBUTTON )
            {
                PrintLog( "WM_MOUSEMOVE: MK_LBUTTON\n" );
            }

            g_nXPos = LOWORD(lParam);
            g_nYPos = HIWORD(lParam);
            //InvalidateRect( hWnd, NULL, TRUE );
        }
        break;
    case WM_LBUTTONDBLCLK:/*左键双击*/
        PrintLog( "WM_LBUTTONDBLCLK\n" );
        break;
    case WM_RBUTTONDBLCLK:/*右键双击*/
        PrintLog( "WM_RBUTTONDBLCLK\n" );
        break;
    case WM_MOUSEWHEEL:/*鼠标滚轮移动*/
        {
            short nDelta = HIWORD(wParam);
            int nX = LOWORD(lParam);
            int nY = HIWORD(lParam);
            CHAR szText[260] = { 0 };
            sprintf( szText,
                "WM_MOUSEWHEEL: Detla=%d, X=%d,Y=%d\n",
                nDelta, nX, nY );
            PrintLog( szText );
        }
        break;
    case WM_DESTROY:
        PostQuitMessage( 0 );
        break;
    }
    return DefWindowProc( hWnd, nMsg,
        wParam, lParam );
}

BOOL RegisterWnd( LPSTR pszClassName )
{
    WNDCLASSEX wce = { 0 };
    wce.cbSize          = sizeof( wce );
    wce.cbClsExtra      = 0;
    wce.cbWndExtra    = 0;
    wce.hbrBackground = HBRUSH(COLOR_WINDOW);
    wce.hCursor          = NULL;
    wce.hIcon          = NULL;
    wce.hIconSm       = NULL;
    wce.hInstance      = g_hInst;
    wce.lpfnWndProc   = WndProc;
    wce.lpszClassName = pszClassName;
    wce.lpszMenuName  = NULL;
    wce.style         = CS_HREDRAW|CS_VREDRAW|CS_DBLCLKS;
    ATOM nAtom = RegisterClassEx( &wce );
    if( 0 == nAtom )
    {
        return FALSE;
    }
    return TRUE;
}

HWND CreateWnd( LPSTR pszClassName )
{
    HWND hWnd = CreateWindowEx( 0,
        pszClassName, "MyWnd",
        WS_OVERLAPPEDWINDOW, CW_USEDEFAULT,
        CW_USEDEFAULT, CW_USEDEFAULT,
        CW_USEDEFAULT, NULL, NULL,
        g_hInst, NULL );
    return hWnd;
}

void DisplayWnd( HWND hWnd )
{
    ShowWindow( hWnd, SW_SHOW );
    UpdateWindow( hWnd );
}

void Message( )
{
    MSG msg = { 0 };
    while( GetMessage( &msg, NULL, 0, 0 ) )
    {
        TranslateMessage( &msg );
        DispatchMessage( &msg );
    }
}

void NewConsole()
{
	/*产生控制台*/
    AllocConsole();

	/*获得控制台标准输出流句柄*/
    g_hStdOut = GetStdHandle(STD_OUTPUT_HANDLE);
    CHAR szText[] = "[sjin] Debug Message......:\n";
	/*将szText 写到控制台*/
    WriteConsole(g_hStdOut, szText, strlen(szText), NULL, NULL);
}

int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
     NewConsole( );
     g_hInst = hInstance;
    RegisterWnd( "MyWnd" );
    HWND hWnd = CreateWnd( "MyWnd" );
    DisplayWnd( hWnd );
    Message( );

    return 0;
}