windows API 创建系统托盘图标

系统托盘在我们使用的程序中很普遍，下面我们来看一个很不错的例子，使用Win32 API实现，对理解系统托盘有些帮助。

#include <windows.h>
#define IDR_PAUSE 12
#define IDR_START 13
/*
#include <shellapi.h>
#pragma   comment(lib,   "shell32.lib")
*/
LPCTSTR szAppName = TEXT("服务程序");
LPCTSTR szWndName = TEXT("服务程序");
HMENU hmenu;//菜单句柄

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    NOTIFYICONDATA nid;
    UINT WM_TASKBARCREATED;
    POINT pt;//用于接收鼠标坐标
    int xx;//用于接收菜单选项返回值

    // 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://窗口创建时候的消息.
        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);
        hmenu=CreatePopupMenu();//生成菜单
        AppendMenu(hmenu,MF_STRING,IDR_PAUSE,"暂停服务");//为菜单添加两个选项
        AppendMenu(hmenu,MF_STRING,IDR_START,"恢复服务");
        break;
    case WM_USER://连续使用该程序时候的消息.
        if (lParam == WM_LBUTTONDOWN)
            MessageBox(hwnd, TEXT("Win32 API 实现系统托盘程序,双击托盘可以退出!"), szAppName, MB_OK);
        if (lParam == WM_LBUTTONDBLCLK)//双击托盘的消息,退出.
            SendMessage(hwnd, WM_CLOSE, wParam, lParam);
        if (lParam == WM_RBUTTONDOWN)
        {
            GetCursorPos(&pt);//取鼠标坐标
            ::SetForegroundWindow(hwnd);//解决在菜单外单击左键菜单不消失的问题
            EnableMenuItem(hmenu,IDR_PAUSE,MF_GRAYED);//让菜单中的某一项变灰
            xx=TrackPopupMenu(hmenu,TPM_RETURNCMD,pt.x,pt.y,NULL,hwnd,NULL);//显示菜单并获取选项ID
            if(xx==IDR_PAUSE) MessageBox(hwnd, TEXT("111"), szAppName, MB_OK);
            if(xx==IDR_START) MessageBox(hwnd, TEXT("222"), szAppName, MB_OK);
            if(xx==0) PostMessage(hwnd,WM_LBUTTONDOWN,NULL,NULL);
            //MessageBox(hwnd, TEXT("右键"), szAppName, MB_OK);
        }
        break;
    case WM_DESTROY://窗口销毁时候的消息.
        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;
}