mousedemo.cpp

c++从入门到精通

#include <windows.h>
#include <stdlib.h>
#include <string.h>

long WINAPI WndProc(HWND hWnd,
					UINT iMessage,
					UINT wParam,
					LONG lParam); //消息处理函数声明.

BOOL InitWindowsClass(HINSTANCE hInstance); //初始化窗口类声明
BOOL InitWindows(HINSTANCE hInstance, int nCmdShow);//初始化窗口声明.
RECT rect; //定义矩形结构体.记录了图形的信息.

int WINAPI WinMain(HINSTANCE hInstance,
				   HINSTANCE hPrevInstance,
				   LPSTR lpCmdLine,
				   int nCmdShow)//主函数
{
	MSG Message;
	if(!InitWindowsClass(hInstance))//初始化窗口类.
		return FALSE;
	if(!InitWindows(hInstance,nCmdShow))//初始化窗口.
		return FALSE;
	while(GetMessage(&Message,0,0,0))
	{
		TranslateMessage(&Message); //消息循环.
		DispatchMessage(&Message);
	}
	return Message.wParam;
}

long WINAPI WndProc(HWND hWnd,
					UINT iMessage,
					UINT wParam,
					LONG lParam)//消息处理函数.
{
	HDC hDC;//定义设备环境句柄.
	WORD x,y;//定义鼠标的位置坐标.
	static BOOL bCircle=FALSE;//设置绘制圆的标志变量.
	static BOOL bRect=FALSE; //设置绘制矩形的标志变量	
	PAINTSTRUCT ps; //定义绘图结构体变量.
	x = LOWORD(lParam);	//得到鼠标的位置.
	y = HIWORD(lParam);

	switch(iMessage)
	{
	case WM_LBUTTONDOWN://处理按下鼠标左键消息.
		bCircle = TRUE;//画圆.
		bRect = FALSE;
		rect.left = x;//圆的左上角坐标为当前鼠标位置.
		rect.top = y;
		break;
	case WM_LBUTTONUP://当松开左键时.绘图标志为false.			
		bCircle = FALSE;
		break;
	case WM_RBUTTONDOWN: //处理按下鼠标右键消息.
		bRect = TRUE;//画矩形.
		bCircle = FALSE;
		rect.left = x;//矩形的左上角坐标为当前鼠标位置.
		rect.top = y;
		break;
	case WM_RBUTTONUP://当松开右键时.绘图标志为false.
		bRect = FALSE;
		break;
	case WM_MOUSEMOVE://处理鼠标移动信息.
		rect.right = x;	//图形的右下角坐标为当前鼠标位置.
		rect.bottom = y;
		if(bRect == TRUE || bCircle == TRUE)
		{
			InvalidateRect(hWnd,NULL,TRUE);	//发出重绘信息.
		}
		break;
	case WM_PAINT:
		hDC = BeginPaint(hWnd,&ps);
		if(bCircle == TRUE) //绘制圆形
		{
			Ellipse(hDC,rect.left,rect.top,rect.right,rect.bottom);
		}
		if(bRect == TRUE) //绘制矩形
		{
			Rectangle(hDC,rect.left,rect.top,rect.right,rect.bottom);
		}
		EndPaint(hWnd,&ps);
		break;
	case WM_DESTROY://退出窗口.
		PostQuitMessage(0);
		return 0;
	default:
		return(DefWindowProc(hWnd,iMessage,wParam,lParam));
	}
	return 0;
}

BOOL InitWindows(HINSTANCE hInstance, int nCmdShow)
{
	HWND hWnd;
	hWnd=CreateWindow("mouseTest",     //窗口类名称.
					"鼠标键测试小程序",//标题栏名称.
					//窗口样式.有标题栏和最大最小化按钮.
WS_OVERLAPPEDWINDOW,	
					CW_USEDEFAULT, //窗口左上角坐标.
					0,
					CW_USEDEFAULT, //采用缺省的高度和宽度.
					0,
					NULL,			//无父窗口.
					NULL,			//无菜单.
					hInstance,		//当前应用实例句柄.
					NULL);			//指向传递给窗口的参数的指针为空
	
if(!hWnd) //创建失败.
		return FALSE;
	ShowWindow(hWnd,nCmdShow);//显示窗口.
	UpdateWindow(hWnd);	//刷新用户区.
	return TRUE;
}

BOOL InitWindowsClass(HINSTANCE hInstance)
{
	WNDCLASS WndClass;

	WndClass.cbClsExtra=0;			//无窗口类扩展.
	WndClass.cbWndExtra=0;			//无窗口实例扩展.
	//背景为白色
	WndClass.hbrBackground=(HBRUSH)(GetStockObject(WHITE_BRUSH));
	WndClass.hCursor=LoadCursor(NULL,IDC_ARROW);//光标为为箭头.
	WndClass.hIcon=LoadIcon(NULL,IDI_APPLICATION);//采用缺省图标.
	WndClass.hInstance=hInstance;//当前实例.
	WndClass.lpfnWndProc=WndProc;//消息处理函数.
	WndClass.lpszClassName="mouseTest";//窗口类名称.
	WndClass.lpszMenuName=NULL;//无菜单.
	WndClass.style=0;//缺省窗口风格.
	return RegisterClass(&WndClass);//返回窗口注册值.
}