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
由于窗口的互相覆盖等,产生需要绘制的区域,那么会产生WM_PAINT消息.
一般情况下,不直接发送WM_PAINT消息,通过API声明需要绘制区域,来产生WM_PAINT消息.
例如,可以使用InvalidateRect声明一个需要重新绘制的区域.
2 WM_PAINT的注意点
2.1 如果一个消息队列中,有多个WM_PAINT消息,只有最后一个WM_PAINT消息会被处理.
2.2 WM_PAINT消息处理中,要清空需要被绘制的区域. BeginPaint
3 WM_PAINT的使用
3.1 WM_PAINT开始时,必须调用BeginPaint
3.2 绘制图形
3.3 WM_PAINT处理后,必须调用EndPaint
看下面的示例代码:
/* 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开始时,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,可以显示的按键,转换成WM_CHAR的消息
2 消息参数
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
如果按键一直不释放,会重复产生
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) { /*产生命令行窗口,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 消息的参数
WPARAM - 当前键盘和鼠标按键状态,例如MK_CONTROL/MK_SHIFT,MK_LBUTTON等
LPARAM - 当前鼠标的坐标,坐标的原点是窗口客户区的左上角.
X坐标 - LOWORD(lParam),低16位
Y坐标 - HIWORD(lParam),高16位
参数具体内容和具体鼠标消息有稍微不同.
3 消息的使用
3.1 基本鼠标消息,只需在窗口处理函数增加消息处理即可. 当消息来临,获取鼠标和按键状态.例如:
case WM_MOUSEMOVE: { int nX = LOWORD(lParam); int nY = HIWORD(lParam); }
附:坐标转换的函数 ClientToScreen可以将鼠标坐标转换为屏幕的坐标.
3.2 双击消息
3.2.1 窗口注册要增加 CS_DBLCLKS 类型
wce.style = CS_DBLCLKS|...;
3.2.2 在窗口处理函数中增加消息处理
3.2.3 产生过程,例如: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.
双击时间间隔可以通过控制面板调整.
3.3 滚轮消息
3.3.1 由于WM_MOUSEWHEEL需要Winnt4.0以上版本支持,所以需要包含在windows.h的头文件前,增加 _WIN32_WINNT 宏定义,
#define _WIN32_WINNT 0x0400
3.3.2 在窗口处理函数中增加消息处理
3.3.3 参数
LPARAM 与其它鼠标消息类同
WPARAM - LOWORD(WPARAM) 表示按键状态
HIWORD(WPARAM) 滚轮滚动幅度,
120的倍数,可以为正负值.
正值: 滚轮向上滚动, 一般窗口向上滚动
负值: 滚轮向下滚动, 一般窗口向下滚动
/* 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); /*窗口更新区域添加一个矩形,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; }