VC 将程序最小化到托盘

这篇文章内容比较基础，最近看到觉得有用，顺便翻译一下
有空可以写一个自己的TrayIcon类，化简这些原始的操作。

Introduction

这篇文章解析了 Shell_NotifyIcon 这个函数用法--用来建立你自己的应用程序的系统托盘图标.
这篇文章给了基本的缩小到托盘的操作过程并让你从中了解.
这篇文章提供8个简单的步骤让你成功的实现在你的程序中建立系统托盘图标.
源代码提供了一个基于对话框的演示程序.

Tray Icons

为了用托盘图标你需要用一个shell函数 :)

BOOL Shell_NotifyIcon( DWORD dwMessage, PNOTIFYICONDATA pnid );

The dwMessage 可选的参数包括 the NIM_ADD,NIM_DELETE and NIM_MODIFY功能分别是添加删除以及修改图标于系统图标.

PNOTIFYICONDATA 结构包括这些系统需要处理的任务图标状态区域消息等信息.
typedef  struct _NOTIFYICONDATA {
    DWORD cbSize;
    HWND hWnd;
    UINT uID;
    UINT uFlags;
    UINT uCallbackMessage;
    HICON hIcon;
    #if (_WIN32_IE < 0x0500)
        TCHAR szTip[64];
    #else
        TCHAR szTip[128];
    #endif    #if (_WIN32_IE >= 0x0500)
        DWORD dwState;
        DWORD dwStateMask;
        TCHAR szInfo[256];
        union {
            UINT uTimeout;
            UINT uVersion;
        } DUMMYUNIONNAME;
        TCHAR szInfoTitle[64];
        DWORD dwInfoFlags;
    #endif    #if (_WIN32_IE >= 0x600)
        GUID guidItem;
    #endif
} NOTIFYICONDATA, *PNOTIFYICONDATA;

*Note: 更完全的信息可以去参考MSDN

Creating the Application

Create a new VC++ dialog based project and call it TrayMin.
创建一个名叫TrayMin的基于对话框的VC++工程

Step: 1

自定义消息于 TrayMinDlg.h 头文件.

               #define WM_TRAY_MESSAGE (WM_USER + 1)

The WM_USER 常量用来帮助用户定义自己的消息被用来建立个人的窗口类, 定义时通常用这种格式 WM_USER+X, 这里 X 是一个整形变量.

*更详细的看MSDN

Step: 2

现在在Now add the DECLARE_MESSAGE_MAP() 之前添加下面的用户函数吧（ TrayMinDlg.h file） afx_msg void OnTrayNotify(WPARAM wParam, LPARAM lParam);

当添加一个图标到托盘时这有一个图标的回调消息，注意到 NOTIFYICONDATA 结构中有uCallbackMessage成员是回调消息识别的关键，它会被传给NIM_ADD（我们之后将会见到更详细的）。当添加托盘图标这个事件发生时，系统发送一个回调函数到由hWnd成员对象指定的窗口过程（winproc），wParam 参数可以用来被识别究竟发生了什么操作。lParam参数存放发生事件相关的鼠标或者键盘消息。举个例子，当一个鼠标指针指向一个托盘图标，lParam将包括WM_MOUSEMOVE

Step: 3

现在添加下面的这行在消息宏中（MessageMap）在TrayMinDlg.cpp

ON_MESSAGE(WM_TRAY_MESSAGE,OnTrayNotify)

现在应该是这样的.

    BEGIN_MESSAGE_MAP(CTrayMinDlg, CDialog)
//{{AFX_MSG_MAP(CTrayMinDlg)
ON_WM_SYSCOMMAND()
ON_WM_PAINT()
ON_WM_QUERYDRAGICON()
ON_MESSAGE(WM_TRAY_MESSAGE ,OnTrayNotify)
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

Step: 4

现在在TrayMinDlg.cpp 定义OnTrayNotify函数，不要忘记在函数头部添加afx_msg。

  afx_msg void CTrayMinDlg::OnTrayNotify(WPARAM wParam, LPARAM lParam)
{
UINT uID;
UINT uMsg;
uID = (UINT) wParam;
uMsg = (UINT) lParam;
if (uID != 1)
return;
CPoint pt;
switch (uMsg )
{
case WM_LBUTTONDOWN:
GetCursorPos(&pt);
ClientToScreen(&pt);
OnTrayLButtonDown(pt);
break;
case WM_RBUTTONDOWN:
case WM_CONTEXTMENU:
GetCursorPos(&pt);
OnTrayRButtonDown(pt);
break;
}
return;
}

Step: 5

现在在TrayMinDlg类添加两个成员函数来相应鼠标事件。

实现鼠标左键单击的相应

函数类型：void
函数声明： OnTrayLButtonDown(CPoint pt)

实现鼠标右键单击的相应

函数类型: void
函数声明: OnTrayRButtonDown(CPoint pt)

OnTrayLButtonDown(CPoint pt)的定义如下.

               void CTrayMinDlg::OnTrayLButtonDown(CPoint pt)
{
MessageBox("You have clicked Left mouse Button ");
}

The Declaration of OnTrayRButtonDown(CPoint pt) is as following.

               void CTrayMinDlg::OnTrayRButtonDown(CPoint pt)
{
//m_menu is the member of CTrayMinDlg as CMenu m_menu;
m_menu.GetSubMenu(0)->TrackPopupMenu(TPM_BOTTOMALIGN|
TPM_LEFTBUTTON|TPM_RIGHTBUTTON,pt.x,pt.y,this);
}

Step: 6

Add two member variable to the CTrayMinDlg.
为CTrayMinDlg添加两个成员变量

Variable Type: NOTIFYICONDATA
Variable Name: m_TrayData;
Variable Type: CMenu
Variable Name: m_menu;

现在添加菜单资源

Step: 7

现在画一个最小化的按钮在对话框设计中
并且添加这个按钮的执行函数

void CShellDlg::OnMinimize()
{
m_TrayData.cbSize = sizeof(NOTIFYICONDATA);
//Size of this structure, in bytes.
m_TrayData.hWnd  = this->m_hWnd;
//Handle to the window that receives notification //messages associated with an icon in the taskbar //status area. The Shell uses hWnd and uID to //identify which icon to operate on when //Shell_NotifyIcon is invoked.
m_TrayData.uID = 1;
//Application-defined identifier of the taskbar icon.//The Shell uses hWnd and uID to identify which icon //to operate on when Shell_NotifyIcon is invoked. You// can have multiple icons associated with a single //hWnd by assigning each a different uID.
m_TrayData.uCallbackMessage  = WM_TRAY_MESSAGE;
//Application-defined message identifier. The system //uses this identifier to send notifications to the //window identified in hWnd. These notifications are //sent when a mouse event occurs in the bounding //rectangle of the icon, or when the icon is selected //or activated with the keyboard. The wParam parameter //of the message contains the identifier of the taskbar //icon in which the event occurred. The lParam parameter //holds the mouse or keyboard message associated with the// event. For example, when the pointer moves over a //taskbar icon, lParam is set to WM_MOUSEMOVE.
m_TrayData.hIcon = this->m_hIcon;
//Handle to the icon to be added, modified, or deleted
strcpy(m_TrayData.szTip,"My Icon");
//Pointer to a null-terminated string with the text //for a standard ToolTip. It can have a maximum of 64 //characters including the terminating NULL.
m_TrayData.uFlags = NIF_ICON|NIF_MESSAGE;
//Flags that indicate which of the other members contain
valid data.
BOOL bSuccess = FALSE;
BOOL BSus = FALSE;
BSus = m_menu.LoadMenu(IDR_MENU1);
if(!(BSus))
MessageBox("Unabled to Loa menu");
bSuccess = Shell_NotifyIcon(NIM_ADD,&m_TrayData);
if(!(bSuccess))
MessageBox("Unable to Set Tary Icon");
else
{
this->ShowWindow(SW_MINIMIZE);
this->ShowWindow(SW_HIDE);
}
}

Step: 8

在退出菜单的执行函数写下如下

Shell_NotifyIcon(NIM_DELETE,&m_TrayData);
DestroyWindow();

现在可以运行程序，并且尝试最小化按钮的使用（他会最小化导系统托盘）。
现在尽情发挥，完善这些步骤，完成自己的系统托盘图标吧！