鼠标放在系统托盘图标上没有提示信息（evc）

whc123 2009-6-1 22:41 楼主

把鼠标移动到系统托盘图标上时，显示提示信息。我使用下面代码实现，可是鼠标放上去后，提示信息并没有出来。

BOOL CMKNKDlg::OnInitDialog()
{
CDialog::OnInitDialog();

// Set the icon for this dialog.  The framework does this automatically
//  when the application's main window is not a dialog
SetIcon(m_hIcon, TRUE); // Set big icon
SetIcon(m_hIcon, FALSE); // Set small icon

CenterWindow(GetDesktopWindow()); // center to the hpc screen

// TODO: Add extra initialization here
m_cTrayIcon.TrayIconAdd( m_hWnd,
ID_TRAY,
TRAY_NOTIFYICON,
LoadIcon( AfxGetInstanceHandle(), MAKEINTRESOURCE(IDI_ICON_MKNK) ),
AfxGetInstanceHandle(),
IDS_TIP,
NULL );
return TRUE;  // return TRUE  unless you set the focus to a control
}

void CTrayIcon::TrayIconAdd( HWND hwnd,
   UINT uID,
   UINT uCallbackMessage,
   HICON hIcon,
   HINSTANCE hInstance,
   UINT uTipID,
   PTSTR pszTip )
{
TrayMessage(hwnd, NIM_ADD, uID, uCallbackMessage, hIcon, hInstance, uTipID, NULL);
}

BOOL CTrayIcon::TrayMessage( HWND hwnd,
   DWORD dwMessage,
   UINT uID,
   UINT uCallbackMessage,
   HICON hIcon,
   HINSTANCE hInstance,
   UINT uTipID,
   PTSTR pszTip )
{
BOOL res = FALSE;
NOTIFYICONDATA tnd;

tnd.cbSize = sizeof(NOTIFYICONDATA);
tnd.hWnd = hwnd;
tnd.uID = uID;
tnd.uFlags = NIF_MESSAGE|NIF_ICON|NIF_TIP;
tnd.uCallbackMessage = uCallbackMessage;
tnd.hIcon = hIcon;
// tnd.szTip[0] = '\0';
if ( dwMessage==NIM_ADD )
LoadString( hInstance, uTipID, tnd.szTip, sizeof(tnd.szTip) );

res = Shell_NotifyIcon(dwMessage, &tnd);
return res;
}

但是鼠标放上去之后，图标并没有出现，不知道咋回事。