WIN32 SDK - 捕获鼠标离开和滞留等事件

文章难易程度：初级

首先要了解 TrackMouseEvent  函数；

此函数当鼠标指针离开或在特定时间内盘旋（滞留）在窗体时投递消息。参数指向 TRACKMOUSEEVENT 结构体。(详细定义及解释请查阅MSDN文档)

typedef struct tagTRACKMOUSEEVENT {
  DWORD cbSize;         //TRACKMOUSEEVENT size.
  DWORD dwFlags;        //Specifies the services requested.
  HWND  hWndtrack;      //Specifies a handle to the window to track.
  DWORD dwHovertime;    //hover time-out.
} TRACKMOUSEEVENT, *LPTRACKMOUSEEVENT;

以下是原码：(注意要在属性页中链接器的导入库中加入 comctl32.lib )

//FileName: MouseLevel.c

#include 
#include           //必须导入此头文件

#ifndef APP_NAME
#define APP_NAME TEXT("My MouseHover test")
#endif

const int SUCCEED =0;

ATOM RegisterFormClass(HINSTANCE);
BOOL InitInstance(HINSTANCE,int);
LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);

int APIENTRY WinMain(HINSTANCE hInstance,
      		     HINSTANCE hPrevInstance,
      		     LPSTR lpCmdLine,
    		     int iCmdShow)
{
 MSG msg;           	
 
 
 RegisterFormClass(hInstance);
 if(!InitInstance(hInstance,iCmdShow))
  return FALSE;
 
 while(GetMessage(&msg,NULL,0,0))
 {
  TranslateMessage(&msg);
  DispatchMessage(&msg);
 }
 
 return SUCCEED;
}

ATOM RegisterFormClass(HINSTANCE hInstance)
{
 WNDCLASSEX wcex;
 
 wcex.cbSize = sizeof(WNDCLASSEX);
 wcex.cbClsExtra = 0;
 wcex.cbWndExtra = 0;
 wcex.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);
 wcex.hCursor = LoadCursor(NULL,IDC_ARROW);
 wcex.hIcon = LoadIcon(hInstance,IDI_APPLICATION); 
 wcex.hIconSm = LoadIcon(NULL,IDI_APPLICATION);
 wcex.hInstance = hInstance;
 wcex.lpfnWndProc = WndProc;
 wcex.lpszClassName = APP_NAME;
 wcex.lpszMenuName = NULL;
 wcex.style = CS_HREDRAW | CS_VREDRAW;
 
 return RegisterClassEx(&wcex);
}

BOOL InitInstance(HINSTANCE hInstance,int iCmdShow)
{
 HWND hWnd;
 
 hWnd = CreateWindowEx(WS_EX_APPWINDOW,
  APP_NAME,
  APP_NAME,
  WS_OVERLAPPEDWINDOW,
  CW_USEDEFAULT,
  CW_USEDEFAULT,
  CW_USEDEFAULT,
  CW_USEDEFAULT,
  NULL,
  NULL,
  hInstance,
  NULL);
 if (!hWnd)
  return FALSE;
 
 ShowWindow(hWnd,iCmdShow);
 UpdateWindow(hWnd);
 
 
 return TRUE;
}

LRESULT CALLBACK WndProc(HWND hWnd,UINT uMsg,WPARAM wParam,LPARAM lParam)
{
 switch(uMsg)
 {
 case WM_MOUSELEAVE:
  MessageBox(hWnd,TEXT("MouseLeave!"),TEXT("MouseLeave"),0);
  break;
 case WM_MOUSEHOVER:
  MessageBox(hWnd,TEXT("MouseHover"),TEXT("MouseHover"),0);
  break;
 case WM_NCMOUSELEAVE:
  MessageBox(hWnd,TEXT("MouseNClient!"),TEXT("MouseNClient!"),0);
  break;
 case WM_MOUSEMOVE:          //因为 TRACKMOUSEEVENT 只发送一次消息，且随着其它消息产生而失效，所以在此消息中调用函数。

  TRACKMOUSEEVENT trmouse;
  trmouse.cbSize = sizeof(TRACKMOUSEEVENT);
  trmouse.dwFlags = TME_LEAVE | TME_HOVER | TME_NONCLIENT;
  trmouse.dwHoverTime = 2000;
  trmouse.hwndTrack = hWnd;
  
  if(!_TrackMouseEvent(&trmouse))   
   return FALSE;
  
  break;
  
 case WM_DESTROY:
  PostQuitMessage(0);
  break;
 default:
  return DefWindowProc(hWnd,uMsg,wParam,lParam);
  break;
 }
 return SUCCEED;
}

//此文件是纯 WIN32 SDK 编写，不需要MFC等支持。可在DOS模式下编译。在WINDOWS98，2000下，VC6，VC7 BETA2中均编译通过且正确执行。