Win32 API 实现系统托盘程序

Win32 API 实现系统托盘程序

#include <windows.h>

LPCTSTR szAppName = TEXT("TrayHelper");
LPCTSTR szWndName = TEXT("TrayIcon");

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
 NOTIFYICONDATA nid;
 UINT WM_TASKBARCREATED;

 // 不要修改TaskbarCreated，这是系统任务栏自定义的消息
 WM_TASKBARCREATED = RegisterWindowMessage(TEXT("TaskbarCreated"));
 switch (message)
 {
 case WM_CREATE:
  nid.cbSize = sizeof(nid);
  nid.hWnd = hwnd;
  nid.uID = 0;
  nid.uFlags = NIF_ICON | NIF_MESSAGE | NIF_TIP;
  nid.uCallbackMessage = WM_USER;
  nid.hIcon = LoadIcon(NULL, IDI_APPLICATION);
  lstrcpy(nid.szTip, szAppName);
  Shell_NotifyIcon(NIM_ADD, &nid);
  break;
 case WM_USER:
  if (lParam == WM_LBUTTONDOWN)
   MessageBox(hwnd, TEXT("Win32 API 实现系统托盘程序!"), szAppName, MB_OK);
  if (lParam == WM_LBUTTONDBLCLK)
   SendMessage(hwnd, WM_CLOSE, wParam, lParam);
  break;
 case WM_DESTROY:
  Shell_NotifyIcon(NIM_DELETE, &nid);
  PostQuitMessage(0);
  break;
 default:
  /*
   * 防止当Explorer.exe 崩溃以后，程序在系统系统托盘中的图标就消失
   *
   * 原理：Explorer.exe 重新载入后会重建系统任务栏。当系统任务栏建立的时候会向系统内所有
   * 注册接收TaskbarCreated 消息的顶级窗口发送一条消息，我们只需要捕捉这个消息，并重建系
   * 统托盘的图标即可。
   */
  if (message == WM_TASKBARCREATED)
   SendMessage(hwnd, WM_CREATE, wParam, lParam);
  break;
 }
 return DefWindowProc(hwnd, message, wParam, lParam);
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
     LPSTR szCmdLine, int iCmdShow)
{
 HWND hwnd;
 MSG msg;
 WNDCLASS wndclass;

 HWND handle = FindWindow(NULL, szWndName);
 if (handle != NULL)
 {
  MessageBox(NULL, TEXT("Application is already running"), szAppName, MB_ICONERROR);
  return 0;
 }

 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("This program requires Windows NT!"), szAppName, MB_ICONERROR);
  return 0;
 }

 // 此处使用WS_EX_TOOLWINDOW 属性来隐藏显示在任务栏上的窗口程序按钮
 hwnd = CreateWindowEx(WS_EX_TOOLWINDOW,
      szAppName, szWndName,
      WS_POPUP,
      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;
}