最新第四讲：鼠标

第四讲：鼠标

●只要鼠标跨越窗口，或者在某窗口中按下鼠标按钮，那么窗口过程函数就会收到鼠标消息，而不管该窗口是否为活动窗口和是否拥有输入焦点窗口。

●鼠标消息：

WM_LBUTTONDOWN

WM_RBUTTONDOWN

WM_LBUTTONUP

WM_RBUTTONUP

WM_MBUTTONUP

WM_LBUTTONDBLCLK

WM_MBUTTONDBLCLK

WM_RBUTTONDBLCLK

WM_MOUSEMOVE

●鼠标双击消息

为：wndclass.style = CS_HREDRAW | CS_VREDRAW | CS_DBLCLKS ;

●重点：

鼠标消息：

WM_LBUTTONDOWN

WM _MBUTTONDOWN

WM_RBUTTONDOWN

WM_LBUTTONUP

WM_RBUTTONUP

WM_MBUTTONUP

WM_LBUTTONDBLCLK

WM_MBUTTONDBLCLK

WM_RBUTTONDBLCLK

WM_MOUSEMOVE

子窗口风格：WS_CHILDWINDOW | WS_VISIBLE

取程序实例句柄：(HINSTANCE)GetWindowLong (hwnd, GWL_HINSTANCE)；

函数MoveWindow (hwndChild[x][y], x * cxBlock, y * cyBlock, cxBlock, cyBlock, TRUE) ;移动窗口和改变窗口大小尺寸，产生WM_SIZE消息。

存取预留在窗口额外字节的函数：

SetWindowLong (hwnd, 0, 0) ;

GetWindowLong (hwnd, 0,0);

设置窗口捕获鼠标函数：

SetCapture(hwnd)；一旦窗口hwnd被设置了捕获鼠标，不管鼠标光标是否在窗口hwnd的边界之内，窗口hwnd都接受鼠标输入。

释放窗口捕获鼠标函数：ReleaseCapture();

WM_MOUSEMOVE消息：每当鼠标移动时，窗口接收WM_MOUSEMOVE 消息，系统此时自动把鼠标光标形状切换到在窗口类中定义的鼠标光标形状，如

wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ;

/*--------------------------------------------------

CONNECT.C -- Connect-the-Dots Mouse Demo Program

(c) Charles Petzold, 1998

--------------------------------------------------*/

#include

#define MAXPOINTS 1000

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,

PSTR szCmdLine, int iCmdShow)

{

static TCHAR szAppName[] = TEXT ("Connect") ;

HWND hwnd ;

MSG msg ;

WNDCLASS wndclass ;

wndclass.style = CS_HREDRAW | CS_VREDRAW ;

wndclass.lpfnWndProc = WndProc ;

wndclass.cbClsExtra = 0 ;

wndclass.cbWndExtra = 0 ;

wndclass.hInstance = hInstance ;

wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ;

wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ;

wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;

wndclass.lpszMenuName = NULL ;

wndclass.lpszClassName = szAppName ;

if (!RegisterClass (&wndclass))

{

MessageBox (NULL, TEXT ("Program requires Windows NT!"),

szAppName, MB_ICONERROR) ;

return 0 ;

}

hwnd = CreateWindow (szAppName, TEXT ("Connect-the-Points Mouse Demo"),

WS_OVERLAPPEDWINDOW,

CW_USEDEFAULT, CW_USEDEFAULT,

CW_USEDEFAULT, CW_USEDEFAULT,

NULL, NULL, hInstance, NULL) ;

ShowWindow (hwnd, iCmdShow) ;

UpdateWindow (hwnd) ;

while (GetMessage (&msg, NULL, 0, 0))

{

TranslateMessage (&msg) ;

DispatchMessage (&msg) ;

}

return msg.wParam ;

}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)

{

static POINT pt[MAXPOINTS] ;

static int iCount ;

HDC hdc ;

int i, j ;

PAINTSTRUCT ps ;

switch (message)

{

case WM_LBUTTONDOWN:

iCount = 0 ;

InvalidateRect (hwnd, NULL, TRUE) ;

return 0 ;

case WM_MOUSEMOVE:

if (wParam & MK_LBUTTON && iCount < 1000)

{

pt[iCount ].x = LOWORD (lParam) ;

pt[iCount++].y = HIWORD (lParam) ;